Del Mar Photonics - Newsletter Fall 2010 - Newsletter Winter 2010

40th EGAS Conference
Technische Universität Graz
Institut für Experimentalphysik
2 - 5 July 2008
European
Group for
Atomic
Systems
ABSTRACTS
Editor: L. Windholz
ORGANIZING COMMITTEE:
W.E. Ernst (Vice Chairman), T. Neger, G. Pottlacher, L. Windholz (Chairman)
CONTACT ADDRESS:
Institut für Experimentalphysik, Technische Universität Graz,
Petersgasse 16, A-8010 Graz
Tel. ++43 316 873 8144 (8141), Fax ++43 316 873 8655
e-mail: windholz@tugraz.at
This volume is published under the copyright of the European Physical Society
(EPS). We want to inform the authors that the transfer of the copyright to EPS should
not prevent an author to publish an article in a journal quoting the original first
publication or to use the same abstract for another conference. This copyright is just
to prevent EPS against using the same material in similar publications.
The EGAS logo shows the hyperfine pattern of a Pr I line in which the intensities of the
components does not follow the theoretically predicted rules.
II
The 40th EGAS Conference is sponsored by
Bundesministerium für
Wissenschaft und Forschung
http://www.bmwf.gv.at
Landeshauptmann Mag. Franz
Voves
Landesrätin Mag. Kristina Edlinger-
Ploder
http://www.graz.at/EN
Technische Universität Graz
http://www.tugraz.at
TOPTICA Photonics AG
http://www.toptica.com
Springer-Verlag GmbH
http://www.springer.com
piezosystem jena GmbH
http://www.piezojena.com/
Coherent (Deutschland) GmbH
http://www.coherent.de/
III
Pfeiffer Vacuum GmbH
http://www.pfeiffer-vacuum.de/
Kurt J. Lesker Company GmbH
http://www.lesker.com/
Radiant Dyes Laser & Accessories
GmbH
http://www.radiant-dyes.com/
iseg Spezialelektronik GmbH
http://www.iseg-hv.de/
ILMVAC GmbH
http://www.ilmvac.de/
Journal of Physics B: Atomic,
Molecular and Optical Physics
http://www.iop.org/journals/jphysb
MEWASA FLEX GmbH
http://www.mewasaflex.de/
Bernhard Halle Nachfl. GmbH
http://www.b-halle.de/
IV
Members of the board of the EUROPEAN GROUP FOR ATOMIC SYSTEMS
Prof. Hartmut HOTOP , CHAIR
Fachbereich Physik, Universität
Kaiserslautern
Postfach 3049
D-67653 KAISERSLAUTERN, Germany
Tel.: +49-631-205-2328
Fax: +49-631-205-3906
E-mail: hotop@physik.uni-kl.de
Prof. Frédéric MERKT (SECRETARY)
Laboratorium für Physikalische Chemie
ETH Zurich, HCI Hönggerberg
CH-8093 ZURICH, Switzerland
Tel.: +41-44 632 4367
Fax.: +41-44 632 1021
E-mail : frederic.merkt@ethz.ch
Dr. Christian BORDAS
Laboratoire de spectrométrie ionique et
moléculaire (LASIM)
université Lyon I bâtiment Kastler
43, boulevard du 11-Novembre 1918
F 69622 VILLEURBANNE, France
Tel. : +33 4 7243 1086
Fax : +33 4 7243 1507
E-mail : bordas@lasim.univ-lyon1.fr
Prof. Mike CHARLTON
Department of Physics
University of Wales Swansea
Singleton Park
SWANSEA SA2 8PP, United Kingdom
Tel. : +44 (0)1792 295 372
Fax : +44 (0)1792 295 324
E-mail : M.Charlton@swansea.ac.uk
Prof. Michael DREWSEN
Departement of Physics and Astronomy
University of Aarhus
NY Munkegade, BYG.520
DK-8000 AARHUS, Denmark
Tel.: +45 8942 3752
Fax.: +45 8612 0740
E-mail : drewsen@phys.au.dk
Prof. Wolfgang E. ERNST
Institute of Experimental Physics
Graz University of Technology
Petergasse 16
A-8010 GRAZ, Austria
Tel. : +43 316 873 8140
Fax : +43 316 873 8655
E-mail : wolfgang.ernst@tugraz.at
Prof. Jürgen ESCHNER
ICFO, Institute of Quantum Optics
Jordi Girona 29, Nexus II
08034 BARCELONA, Spain
Tel: +34-933964695
Fax: +34-934137943
E-mail : Juergen.Eschner@icfo.es
Prof. Nikolay KABACHNIK
Department of physics
Moscow State University,
Leninskiz Gory, Moscow 119992,
Russia
Tel. +7 495 939 3605
Fax +7 495 939 0896
E-mail : nkabach@mail.ru
V
Prof. Eva LINDROTH
Atomic Physics, Fysikum
Stockholm University
AlbaNova University Centre
SE-106 91 STOCKHOLM, Sweden
Tel.: +46-8 5537 8616
Fax.: +46-8 5537 8601
E-mail : lindroth@physto.se
Prof. Krzysztof PACHUCKI
Institute of Theoretical Physics
Warsaw University
Ul. Hoza 69
PL - 00-681 WARSAW, Poland
Tel.: +48-22-5532246
Fax: +48-22-6219475
E-mail: Krzysztof.Pachucki@fuw.edu.pl
Prof. Antonio SASSO
Università di Napoli Federico II
Dipartemento di Scienze Fisiche
Complesso Universitario Monte S.
Angelo
Via Cinthia, I-801236 NAPOLI, Italia
Tel. +39 081 67 6120 / 6273
Fax +39 081 67 6346
E-mail: sasso@na.infn.it
Prof. Kenneth TAYLOR
Department of applied mathematics and
theoretical physics
Queen's University of Belfast
BELFAST BT7 1NN, Northern Ireland,
UK
Tel. : 028 9033 5049
Fax : 028 9023 9182
E-mail : k.taylor@qub.ac.uk
Prof. Nikolay V. VITANOV
Department of Physics,
Sofia university
James Bourchier 5 Blvd.
Tel. +359 2 8161 652
Fax +359 2 9625 276
E-mail: vitanov@phys.uni-sofia.bg
Prof. Marc J.J. VRAKKING
AMOLF-FOM
Institute for Atomic and molecular
Physics
Kruislaan 407
1098 SJ AMSTERDAM, The
Netherlands
Tel. ?
Fax +31 20 6684106
E-mail: vrakking@amolf.nl
Webmaster
Prof. Henri-Pierre GARNIR
Université de Liège
IPNAS, Sart Tilman B15
B-4000 LIEGE, belgium
Tel. +32 4 366 3764
Fax +32 4 366 2884
E-mail: hpgarnir@ulg.ac.be
VI
Contents
This book contains all abstracts arrived in Graz before June 15, 2008
VII
VIII
A Brief History of Elemental Carbon
R.F. Curl, jr.
University Professor Emeritus, Pitzer-Schlumberger Professor of Natural Sciences
Emeritus, Professor of Chemisty Emeritus, Departement of Chemistry, Rice University,
Houston, Texas, U.S.A., rfcurl@rice.edu
Carbon is the only element that humanity has routinely been in contact with in reasonably
pure form since the origin of the species. With this much experience with it, one might
think that the chemistry of pure carbon is completely understood and developed. Nothing
could be further from the real situation. Although many important advances have been
made recently, there is much that is not understood and probably much to be discovered
about the chemistry and uses of this extremely flexible element. This talk will be a rapid
survey of human experience with elemental carbon and the variety of forms it can take.
EL 1
1
Non-demolition photon counting and field quantum
state reconstruction in a cavity: a new way to look at
light
Serge Haroche
ENS and Collège de France, Paris
While usual photo-detection destroys light quanta, we have developed a quantum nondemolition
way to count photons trapped in a cavity without absorbing them, making
it possible to measure the same field repeatedly. We use as detectors atoms prepared in
Rydberg states which cross the cavity one at a time and behave as microscopic clocks
whose ticking rate is affected by light. By measuring the clocks’ delay, information is
extracted without energy absorption and the field progressively collapses into a welldefined
photon number state. Quantum jumps between decreasing photon numbers are
recorded as the cavity field subsequently relaxes towards vacuum. This new way to
look at light can also generate coherent superpositions of photonic states with different
phases called "Schrödinger cats". By exploiting information provided by sequences of
atoms crossing the cavity and interacting non-destructively with its field, we reconstruct
these Schrödinger cat states which are represented in phase space by Wigner functions
exhibiting striking non-classical features. We directly monitor in this way the process
of decoherence in experiments opening new avenues for the exploration of the boundary
between the quantum and classical worlds.
PL 1
2
Theory and Spectroscopy of Parity Violation in
Chiral Molecules
Martin Quack
ETH ZÄurich, Laboratorium fÄur Physikalische Chemie, Wolfgang-Pauli-Str. 10,
CH-8093 ZÄurich,
web: www.ir.ethz.ch; email: Martin@Quack.ch
Parity violation plays a crucial role in the Standard Model of Particle Physics and ac-
cording to current understanding it has crucial connections to fundamental symmetry
violations in general and to such fundamental phenomena as the existence of mass of the
elementary particles (see [1,2]) and references cited therein). In chemistry, one important
consequence is a \parity violating energy di®erence"¢PV E of the ground state energies of
enantiomers of chiral molecules, corresponding to a non zero enthalpy of stereomutation
or enantiomerisation ¢RH0
0 = NA¢PV E, which would be exactly zero if perfect inversion
symmetry were true. An experiment to measure this very small energy di®erence in the
sub-femto-eV (or atto-eV) range, typically, has been proposed some time ago [3]. Recent
improved theory [4,5,6] predicts parity violating potentials to be larger by about two or-
ders of magnitude for the prototype compound H2O2 and related molecules, as compared
to older theories, and this large increase has been con¯rmed by subsequent independent
theoretical results in several groups. Thus the prospects for successful experiments look
brighter today than ever before [7].
In the lecture we will discuss the current status of the ¯eld and report in some detail on
the various spectroscopic approaches, which can be used, as well as the current challenges
of these experiments [7]. If time permits, even more fundamental symmetry violations
such as CP and CPT violation will be discussed [1,8].
References
[1] M. Quack, in \Modelling Molecular Structure and Reactivity in Biological Sys-
tems", Proc. 7th WATOC Congress, Cape Town January 2005 (Eds.: K. J. Naidoo,
J. Brady, M. J. Field, J. Gao, M. Hann), Royal Society of Chemistry, Cambridge
(2006), ISBN 0-85404-668-2, pages 3 - 38
[2] M. Quack, Nova Acta Leopoldina 81, 137 (1999), (earlier version of [1], in German).
[3] M. Quack, Chem. Phys. Lett. 132, 147 (1986); M. Quack, Angew. Chem. Int. Ed.
(Engl.) 28, 571 (1989).
[4] A. Bakasov, T. K. Ha, M. Quack, in \Chemical Evolution, Physics of the Origin
and Evolution of Life ", Proc. of the 4th Trieste Conference (1995) (Eds.: J. Chela-
Flores, F. Raulin), Kluwer Academic Publishers, Dordrecht (1996), ISBN 0-7923-
4111-2, pages 287-296.
[5] A. Bakasov, T. K. Ha, M. Quack, J. Chem. Phys. 109, 7263 (1998).
[6] R. Berger, M. Quack, J. Chem. Phys. 112, 3148 (2000).
[7] M. Quack, J. Stohner, M. Willeke, Annu. Rev. Phys. Chem. 59, 741 (2008).
[8] M. Quack, Paper at EGAS Conference 2 to 5 July (2008)
PL 2
3
Precision Experiments with Highly Charged Ions
H.-Jurgen Kluge for the HITRAP Collaboration
GSI/Darmstadt and University of Heidelberg, Germany
Highly-charged ions (HCI) con ned in Penning traps and storage rings have been applied
for high-precision experiments such as mass spectrometry or x-ray, laser and radiofrequency
spectroscopy. Storage and cooling of HCI in trapping devices are prerequisites
for such high-accuracy experiments in which even a single stored particle can be observed.
In the case of a radioactive ion, the fate of an individual ion, undergoing a nuclear decay,
can be studied in detail by observing the disappearance of the signal of the mother and
the appearance of that of the daughter isotope. Since the mass resolving power of mass
spectrometry using Penning traps or storage rings increases with the charge state, charge
breeding and the use of HCI is planned for quite a number of radioactive beam facilities.
Few-electron ions are simple systems which are calculable by theory with high accuracy.
In such systems, the electric eld strength increases roughly with the third power of the
nuclear charge and reaches values much larger than presently achievable with the most
powerful short-pulse lasers. These HCI up to hydrogen-like U91+ are testing grounds for
QED in the little explored regime of extreme electromagnetic elds.
In order to increase the accuracy further for investigating simple systems, the Highlycharged
Ion TRAP (HITRAP) facility is presently being built up at GSI. Stable or radioactive
HCI are produced by stripping relativistic ions in a target and injecting them
into the storage ring ESR at GSI. After electron cooling and deceleration to 4 MeV per
nucleon, these ions are ejected out of the storage ring, decelerated further in a linear
decelerator, and injected into a Penning trap where a temperature of 4 K is reached by
electron and resistive cooling. From here, the cooled HCI are transferred at low energies
to experimental setups. A large number of unique experiments with very heavy ions up
to hydrogen-like U91+ are being prepared by the international HITRAP Collaboration:
Clean samples of stored and cooled HCI in a chosen speci c charge state can be
investigated by observation of x-rays from a quasi point-like source.
If the accuracy of QED calculations is improved, the ne structure constant can
be determined with high accuracy measuring the g-factor of the bound electron.
Mass measurements can be performed with extreme accuracy of better than 10􀀀11
and with single-ion sensitivity by using stored HCI.
A measurement and comparison of the nuclear g-factor of the bare nucleus with that
of the neutral atom allows one to check calculations of the diamagnetic correction
for the rst time.
The hyper ne structure of the ground state in hydrogen-like systems can be determined.
Optical pumping of the M1 transition will result in electronic and nuclear
polarization enabling clean nuclear-decay experiments and, in this way, sensitive
tests of weak interaction.
Recoil ion momentum spectroscopy, ion-surface interaction experiments, and hollowatom
spectroscopy can be performed in a regime of extr. low energies using HCI.
PL 3
4
AtomChips:
Integrated circuits for matter waves
Jorg Schmiedmayer
Atominstitut der  Osterreichischen Universitaten, TU-Wien
AtomChips [1] aim at the miniaturization and integration of quantum optics and atomic
physics on to a single chip, analogous to electronic circuits. It combines the best of both
worlds: The perfected manipulation techniques from atomic physics with the capability
of nanofabrication. AtomChips promise to allow coherent manipulation of matter waves
on the quantum level by using high spatial resolution electro magnetic potentials from
structures on the atom chip or by employing adiabatic radio frequency (RF) or micro
wave (MW) potentials.
The talk will give an overview of the recent advances in the concepts, fabrication and
experimental realization of AtomChips by illustrating the many di erent tasks that can
be performed using ultra cold or Bose-Einstein condensed (BECs) atoms manipulated on
the chip. These range from measuring magnetic and electric elds with unprecedented
sensitivity by observing the density modulations in trapped highly elongated 1d BECs
[2], to fundamental studies of the universal properties in low dimensional systems like non
equilibrium dynamics and coherence decay [3] or signatures of thermal and quantum noise
[4] in one dimensional super uids. The talk will give an overview of the recent advances
and experiments.
This work was supported by the European Union MC network AtomChips, integrated
project SCALA, the DIP the FWF and the Wittgenstein Prize.
[1] For an overview see: Microscopic atom optics: from wires to an atom chip. Folman,
R., Krger, P., Schmiedmayer, J., Denschlag, J. Henkel,C., Adv. At. Mol. Opt. Phys.
48, 263 (2002).
[2] St. Wildermuth et al. Nature 435, 440 (2005); S. Aigner et al. Science 319, 1226
(2008)
[3] Ho erberth et al. Nature 449, 324 (2007)
[4] Ho erberth et al. Nature Physics (2008), DOI:10.1038/nphys941; arXiv:0710.1575
PL 4
5
Optical Atomic Clocks at the Frontiers of Metrology
Fritz Riehle
Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38 116 Braunschweig Germany
Several optical atomic clocks are now beginning to outperform the best caesium atomic
clocks that represent the realization of the definition of the unit of time in the International
Systems of Units (SI). Consequently, four optical frequency standards have recently been
selected and recommended as secondary representations of the second by the International
Committee of Weights and Measures. Among them are the 171Yb+ frequency standard at
688 THz which is based on an electric quadrupole transition of a single, laser-cooled ion
held in a rf Paul trap and the 87Sr standard at 429 THz based on a cloud of neutral atoms
in an optical lattice at the magic wavelength. Due to the large number of atoms that can
be interrogated in parallel, neutral atom optical frequency standards and clocks allow for
unprecedented high short-term stability as compared to single ion standards whereas up
to now single-ion standards seem to have the best prospects for fractional uncertainties
around 10−17 and below. In the talk the status of both standards at PTB and elsewhere
will be reviewed.
Apart from possible future realizations of the second those optical clocks clocks are used
to give upper limits for a possible drift of fundamental constants that is asked for by a
certain class of theories that aim to combine quantum theory and General Relativity.
The unprecedented high accuracies and stabilities of optical clocks require novel solutions
for meaningful comparisons of remote optical clocks. A particular interesting, novel
and challenging approach is to phase-coherently shift the frequency of a particular optical
atomic clock to the 1.54 μm band by means of a femtosecond comb, to transfer
this frequency over an existing commercial telecommunication network and to employ a
second frequency comb at the user end for comparison or calibration of the optical frequency
standard at this place. First experimental results and planned realizations will be
reported.
The remote comparison of optical clocks with fractional uncertainties around 10−18 is
extremely challenging. A frequency shift of this magnitude results e.g. from the Doppler
effect already by a relative motion of a few micrometers per day or by the gravitational
red shift due to a vertical height difference of 1 cm in the gravitational potential near
the surface of the Earth. It can be expected that frequency stabilized lasers of such high
accuracy apart from their use as precise clocks might be used as sensitive probes for their
relativistic environment and for other novel applications.
PL 5
6
Alkali Atoms, Dimers, Exciplexes and Clusters
in 4He Crystals
A. Weis, P. Moroshkin, V. Lebedev, and A. Hofer
Physics Department, University of Fribourg, Chemin du Mus¶ee 3, CH-1700 Fribourg
A closed-shell He atom and a single-electron alkali atom strongly repel each other be-
cause of the Pauli principle. As a consequence, an alkali atom immersed into condensed
(super°uid or solid) 4He forms a spherical bubble state, in which the alkali repels the He
quantum °uid/solid by imposing its own symmetry on the local He environment. For 15
years we have investigated such atomic bubbles in solid 4He using optical and magnetic
resonance spectroscopy.
In this talk I will ¯rst review our high resolution magnetic resonance studies performed on
solid He matrix-isolated alkali atoms in the radio-frequency and microwave domains with
special emphasis on their sensitive dependence on the crystalline structure (body-centered
cubic, bcc, versus hexagonally close-packed, hcp) of the helium matrix.
In recent years we have extended the purely atomic studies to larger bound complexes,
such as exciplexes, dimers and clusters. I will present some of our intriguing recent results:
² In their respective ground states, alkali and He atoms are the worst enemies in the
periodic table and strongly repel each other. Excited alkali atoms, however, attract
He atoms and form bound states (so-called exciplexes), in which up to 7 He atoms
can be attached to one alkali atom.
² Cs2 and Rb2 dimers in solid He can be excited via a large variety of absorption
bands, and the deexcitation proceeds either by photodissociation or by emission
of radiation. We made the strange observation that, irrespective of the excitation
band, dimer °uorescence is only emitted on the (1)3¦u ! X 1§g triplet-singlet
transition which is forbidden in the free dimer.
² When the ¯rst excited P1=2 state of an alkali atom is populated by direct atomic
excitation, it °uoresces at 879 nm (1.7% blueshifted from the free atomic transition
at 894 nm), a quantitatively well explained fact. However, when the same state is
populated by photodissociation of the dimer, the emission wavelength is 885 nm.
We attribute this e®ect to the formation of an entangled diatomic bubble state.
² The doped region of the He crystal has a bluish color that originates from Mie
scattering by alkali clusters, the size distribution of which can be inferred from the
extinction spectrum.
² When the doped He crystal is molten by lowering the He pressure, the doped
(column-shaped) region remains solid at pressures, where pure He is super°uid.
We present experimental support for our hypothesis that this new form of solid He
is an amorphous or crystalline ionic structure formed by snowballs (nanoscopic solid
He structures formed around positive ions) and electron bubbles.
PL 6
7
Generation of Short Wavelength Radiation via
Coherent Hyper Raman Superradiance
Marlan O. Scully
Texas AM University and Princeton University
We nd that intense short pulses of XUV radiation can be produced by cooperative
spontaneous emission from visible or IR laser pulses driving atoms or ions. The process
depends on the generation and utilization of atomic coherence as is the case in lasing
without inversion. However, the radiation process is not stimulated emission, but is
rather cooperative spontaneous emission in the since of Dicke. More precisely, the many
atom mathematics of the problem is the same as that of coherent anti-Stokes Raman
scattering.
PL 7
8
Cold Atom Interferometry
for Gravitational Experiments
G. M. Tino
Dipartimento di Fisica and LENS Laboratory - Università di Firenze
Istituto Nazionale di Fisica Nucleare, Sezione di Firenze
via Sansone 1, Polo Scientifico, I-50019 Sesto Fiorentino (Firenze), Italy
E-mail: guglielmo.tino@fi.infn.it
Experiments we are performing using atom interferometry to determine the
gravitational constant G [1] and test the Newtonian gravitational law at micrometric
distances [2] will be presented. Other experiments in progress, planned or being
considered using atom interferometers in ground laboratories [3] and in space [4] will be
also discussed.
References
1. G. Lamporesi, A. Bertoldi, L. Cacciapuoti, M. Prevedelli, and G. M. Tino, Phys. Rev. Lett. 100, 050801,
(2008).
2. G. Ferrari, N. Poli, F. Sorrentino, and G. M. Tino, Phys. Rev. Lett. 97, 060402, (2006).
3. M. de Angelis, A. Bertoldi, L. Cacciapuoti, A. Giorgini, G. Lamporesi, M. Prevedelli, G. Saccorotti, F.
Sorrentino, G.M. Tino, to be published.
4. G. M. Tino, L. Cacciapuoti, K. Bongs, Ch. J. Bordé, P. Bouyer, H. Dittus, W. Ertmer, A. Görlitz,
M. Inguscio, A. Landragin, P. Lemonde, C. Lammerzahl, A. Peters, E. Rasel, J. Reichel, C. Salomon,
S. Schiller, W. Schleich, K. Sengstock, U. Sterr, M. Wilkens, Nuclear Physics B (PS) 166, 159, (2007).
PL 8
9
Photodetachment microscopy in a magnetic field
C. Blondel, W. Chaibi, C. Delsart and C. Drag
Laboratoire Aim´e-Cotton, Centre national de la recherche scientifique,
Univ. Paris-sud 11, bˆatiment 505, F-91405 Orsay, France
Among some remarkable properties of charged-particle interferometry, one has known for
sixty years of the case where a perturbation can induce a shift of interference fringes even
though no physical field acts on the classical particle trajectories [1,2]. In such an extreme
case, of course, all trajectories remain unperturbed, and the fringes shift with respect to
a motionless envelope.
Less attention was paid to the other extreme situation, where a uniform, e.g. magnetic
field acts on all possible trajectories of the interferometer volume. In this case, the Lorentz
force is expected to bend all trajectories, while the added magnetic flux is expected to
change the interferometer phase. No doubt that, on a microscopic scale, the latter (phase
shift) is the quantum-mechanical explanation of the former (trajectory shift). Interferometers,
however, provide a situation where the added magnetic flux is no longer between
infinitesimally close trajectories, but between pairs of trajectories with a macroscopic separation.
In the ordinary photodetachment microscopy situation [3], a μT is enough to
produce a 100 radian phase shift between trajectories of the most sensitive pairs, which
is definitely beyond the perturbative regime.
A review of past interference experiments shows that the identity of fringe and trajectory
shifts was actually seldom addressed. The well-known sensitivity of interferometers to
external perturbations can even be misinterpreted as an argument for a greater shift of
the interference fringes. On the other hand, analogy of the magnetic field action to the
effect of rotation of the whole apparatus can serve as an argument for the identity of
fringe and trajectory displacements. Rotation vs. magnetic field analogy is however only
a first-order approximation.
Photodetachment microscopy provides us with a remarkable situation where the electron
interference pattern has a clear-cut envelope. Experiments done with and without a magnetic
field show a pattern shifted with no internal change, which demonstrates that all
trajectories and fringes undergo the same macroscopic displacement together [4]. This has
important consequences for the reliability of electron affinity measurements performed by
photodetachment microscopy. The property can actually be demonstrated by vector analysis.
A non-zero second-order effect is expected however, which produces but a negligible
phase-shift in the present experimental situations.
References
[1] W. Ehrenberg and R.E. Siday, Proc. Phys. Soc. B 62, 8 (1949)
[2] Y. Aharonov and D. Bohm, Phys. Rev. 115, 485 (1959)
[3] C. Blondel, C. Delsart and F. Dulieu Phys. Rev. Lett. 77, 3755 (1996)
[4] W. Chaibi, C. Blondel, C. Delsart and C. Drag, Europhys. Lett. 82, 20005 (2008)
PL 9
10
Laser Induced { Tunneling, Electron Di®raction and
Molecular Orbital Imaging
Paul Corkum
University of Ottawa
National Research Council of Canada
Ottawa, Ontario, Canada
Multiphoton ionization in the tunneling limit is similar to tunneling in a scanning tunnel-
ing microscope. In both cases an electron wave packet tunnels from a bound (or valence)
state to the continuum. I will show that multiphoton ionization provides a route to extend
tunneling spectroscopy to the interior of transparent solids. Rotating the laser polariza-
tion is the analogue of scanning the STM tip - a means of measuring the crystal symmetry
of a solid [1].
In gas phase molecules the momentum spectrum of individual electrons can be measured.
I will show that, as we rotate the molecule with respect to the laser polarization, the
photoelectron spectrum samples a ¯lter projection of the momentum wave function (the
molecular analogue to the band structure) of the ionizing orbital [2].
Some electrons created during multiphoton ionization re-collide with their parent ion. I
will show that they di®ract, revealing the scattering potential of the ion - the molecular
structure [3]. The electron can also interfere with the initial orbital from which it sepa-
rated, creating attosecond XUV pulses or pulse trains. The amplitude and phase of the
radiation contains all information needed to re-construct the image of the orbital [4] (just
as a sheared optical interferometer can fully characterize an optical pulse).
Strong ¯eld methods provide an extensive range of new tools to apply to atomic, molecular
and solid-state problems.
[1] M. Gertsvolf, D. Grojo, D. Rayner and P. B. Corkum, unpublished results.
[2] A. Staudte, D. M. Villeneuve, M. Yu Ivanov and P. B. Corkum, unpublished results.
[3] M. Meckel, D. Comtois, D. Zeidler, D. M. Villeneuve, R. DÄorner and P. B. Corkum,
unpublished results.
[4] J. Itatani et al, Nature 432, 867 (2004).
PL 10
11
Few-electron dynamics
in the interaction with strong fields
Armin Scrinzi
Vienna U. of Technology, Photonics Institute
Simple single active electron models have been highly successful in describing the interaction
of strong laser fields with atoms and have inspired a large number of experiments.
Still, the validity and predictive power of these models for few-electron atoms and in
particular for molecules remains to be investigated. There are only few (semi-)analytical
models that include electron correlation. Alternatively, the numerical integration of the
time-dependent Schr¨odinger equation (TDSE) is a challenging task because of the exponential
growth of the problem size with the particle number, which has largely limited
computations to n = 2 active electrons.
In recent years, we have developed the MCTDHF (Multi-Configuration Time-Dependent
Hartree-Fock) method for the solution of the TDSE for atoms and molecules in IR laser
fields. The method scales like ∼ n
4 with the number of active electrons, as opposed to
the exponential scaling encountered in direct discretizations of the TDSE. Different from
time-dependent density-functional theory, which has an even more favorable n
2-scaling,
MCTDHF allows for the straight forward computation of two-electron observables and
for systematic convergence studies.
As examples, we show calculations of the strong field ionization of linear molecules with
up to 6 active electrons, electron-assisted laser ionization of an atom, high harmonic
generation on a diatomic 4-electron molecule, and the XUV-IR pump-probe ionization of
Helium. While for our parameters, the effects of electron correlation on ionization are
rather straight forward and can be incorporated into simple models, we find dramatic
qualitative modifications of the high harmonic spectrum by multi-electron effects. For
the pump-probe scenario, we find find significant crosstalk between the XUV pump and
the IR probe pulses.
PL 11
12
Molecular reaction dynamics at low energies
Roland Wester
Department of Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg,
Germany
Low-energy collisions of small molecules represent model systems for complex quantum
reaction dynamics. The dynamics of negative ion reactions are particularly interesting,
being characterized by a corrugated potential energy landscape that originates in the
competition of long-range attractive and short-range repulsive forces. Scattering on such
multi-dimensional potentials only leads to reaction products if the different molecular
degrees of freedom are sufficiently coupled. This leads to unexpected dynamical features
in the scattering cross sections.
To study ion-molecule reaction dynamics, we have developed two complementary experimental
approaches. Using velocity map imaging in combination with crossed beams at
low energy, the differential scattering cross section of negative ion reactions is measured
at a controlled relative energy [1]. This setup has allowed us to image the nucleophilic
substitution reaction, a prototypical reaction in organic synthesis, and we have observed
several distinct reaction mechanisms as a function of collision energy [2]. Currently we
are preparing experiments to investigate the stereodynamics of reactions that take place
in a strong laser field.
Using a 22-pole ion trap, which allows for efficient buffer gas cooling of all degrees of
freedom of trapped molecular ions, we study reaction rates of negative ions at cryogenic
temperatures down to 8 Kelvin [3,4]. Due to the recent detection of negative ions in interstellar
molecular clouds, these measurements have become important for understanding
the interstellar abundance of anions. Absolute cross sections for anion photodetachment,
a significant destruction mechanism in photon dominated regions, are measured in our
22-pole trap with high systematic accuracy [5]. In addition, we have observed unexpected
temperature-dependences for a proton transfer reaction as well as for a ternary cluster
stabilization reaction at low temperatures [6,7]. In the future this work will be extended
to ultracold ion-atom interactions.
[1] J. Mikosch, U. Fr¨uhling, S. Trippel, D. Schwalm, M. Weidem¨uller, R. Wester, Phys.
Chem. Chem. Phys. 8, 2990 (2006)
[2] J. Mikosch S. Trippel, C. Eichhorn, R. Otto , U. Lourderaj, J. X. Zhang, W. L. Hase,
M. Weidem¨uller, R. Wester, Science 319, 183 (2008)
[3] J. Mikosch, U. Fr¨uhling, S. Trippel, D. Schwalm, M. Weidem¨uller, R. Wester, Phys.
Rev. Lett. 98, 223001 (2007)
[4] J. Mikosch et al., submitted
[5] S. Trippel, J. Mikosch, R. Berhane, R. Otto, M. Weidem¨uller, R. Wester, Phys. Rev.
Lett. 97, 193003 (2006)
[6] R. Otto et al., submitted
[7] J. Mikosch et al., submitted
PR 1
13
1, 2, 3 Photons for Trapped Ion Spectroscopy
C. Champenois, G. Hagel, M. Houssin, C. Zumsteg, F. Vedel, and M. Knoop
CNRS/Université de Provence, Centre de St.Jérôme, Case C21,
13397 Marseille Cedex 20, France
Rf trapped ions are versatile candidates for a large panel of applications ranging from
quantum information to the creation of cold molecules. Sample size can range from
a single to 106 ions, and the internal and external energy states of the atoms can be
controlled with high precision. In our experiment, we focus on di erent protocols in
frequency metrology using rf trapped Ca+ ions.
A single Ca+ ion, cooled in a miniature radiofrequency trap and con ned in the Lamb-
Dicke regime, is an almost perfectly isolated atomic system suited for long interroga-
tion times. The electric quadrupole transition between the ground 4S1=2 and the upper
metastable 3D5=2 state is a rst choice for a frequency standard in the optical domain, its
natural linewidth below 200 mHz results in a quality factor = higher than 2 1015 [1].
Probing of the clock transition of a single ion is carried out using quantum jump statistics
which requires interrogation times of several seconds to avoid power broadening. Care
must be taken to eliminate residual e ects which may perturb the one-photon interro-
gation. The line width of the probe laser (local oscillator) should reach the hertz level for
a duration at least as long as the interrogation time to take full advantage of the quality
factor of the clock transition.
Clock performances are limited by the signal to noise ratio which can be obtained on
a single ion. We propose a novel interrogation protocol allowing to separate the two-
photon two-color cooling laser and the uorescence detection in two distinct wavelength
domains, which allows detection without background and thus high cycle times. An
additional advantage is the tuning of the limit temperature only by the variation of laser
detuning and power [2]. This protocol implying cooling on a dipole forbidden transition
has been demonstrated experimentally [3].
The interrogation of an ion cloud by a three-photon protocol can be made in a Doppler-
free con guration of the laser beams [4]. A coherent superposition of the two metastable
states is obtained by a coherent population trapping protocol, providing a high-resolution
dark line in the THz domain. The referenced 1.8 THz signal can be propagated over long
distances, as the useful information is carried by three optical photons.
[1] C. Champenois et al., Phys. Lett. A 331/5, 298-311 (2004)
[2] C. Champenois et al., Phys. Rev. A 77, 033411 (2008)
[3] R. Hendricks et al., Phys. Rev. A 77, 021401(R) (2008)
[4] C. Champenois et al., Phys. Rev. Lett. 99, 013001 (2007)
PR 2
14
Non-linear Photoionization in the Soft X-ray Regime
Mathias Richter and Andrei A. Sorokin
Physikalisch-Technische Bundesanstalt, Berlin, Germany
The investigation of non-linear effects on photon-matter interaction like multi-photon ionization
was restricted, for many years, to optical wavelengths. This has changed with the
development of X-ray lasers like the Free-Electron LASer in Hamburg FLASH [1]. First
gas-phase studies performed at FLASH demonstrate that non-linear photoionization in
the spectral range of the classical photoelectric effect, i.e. at photon energies above atomic
ionization thresholds, differs in some respect from the behaviour in the optical regime [2-
4]. Here, we present results of ion Time-Of-Flight (TOF) spectroscopy on rare gases at
peak irradiance levels above 1013 W cm−2 up to 1016 W cm−2 and photon energies around
40 eV and 90 eV. Non-linearities due to space-charge effects, target depletion, and sequential
and direct multi-photon ionization were observed. Our result of 21-fold ionization of
xenon seems to be even beyond a perturbative description [4]. The work is related to
the development of photon diagnostic tools that are based on gas-phase photoionization
but might be of significance for any experiment at current and future X-ray laser facilities.
References
[1] W. Ackermann et al., Nat. Photonics 1, 336 (2007)
[2] A.A. Sorokin, S.V. Bobashev, K. Tiedtke, M. Richter, J. Phys. B 39, L299 (2006)
[3] A.A. Sorokin, S.V. Bobashev, K. Tiedtke, M. Wellh¨ofer, M. Richter, Phys. Rev. A
75, 051402(R) (2007)
[4] A.A. Sorokin, S.V. Bobashev, T. Feigl, K. Tiedtke, H. Wabnitz, M. Richter, Phys.
Rev. Lett. 99, 213002 (2007)
PR 3
15
Multi-photon ionization and excitation oft the rare
gases by Free Electron Laser radiation
Uwe Becker
Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Germany
Multi-photon processes in the vacuum ultraviolet and soft X-ray regions became experi-
mentally accessible only very recently when the Free Electron Laser FLASH at DESY in
Hamburg was put into operation. The high brilliance of its light pulses makes it possible
to study non-linear processes in the photoionization of atoms, molecules and clusters.
First priority in the study of these processes has the spectroscopy of atoms, in particular
rare gas atoms. The study of non-linear processes in theses atoms was due to their high
ionization thresholds with normal laser radiation not feasible; only the SASE-FEL with
its ultra-bright VUV radiation made this now possible.
Studying the intensity dependence proved the well-known relationship between the num-
ber of involved photons and the exponential behavior of photon intensity versus ionization
probability. More interesting was the relationship between simultaneous and sequential
double photo-ionization. Our preliminary data analysis points to a predominance of the
latter by two photons, if the necessary threshold energy for this process is exceeded. The
last in a way most interesting aspect in this regard is the angular distribution of the
corresponding photoelectrons.
Multi-photon processes are characterized by photoelectron angular distributions, which
re ect the number of photons involved in the ionization process. This general rule is
clearly exhibited in our angular distribution results. However, the di erent photolines
show very distinct di erences in this respect, which needs further theoretical explanation.
PR 4
16
Ultracold deeply-bound Rb2 molecules
F. Lang1, K. Winkler1, C. Strauss1, R. Grimm1;2 & J. Hecker Denschlag1
1 Institut fÄur Experimentalphysik und Quantenzentrum, UniversitÄat Innsbruck, A-6020
Innsbruck, Austria
2 Institut fÄur Quantenoptik and Quantuminformation der sterreichischen Akademie der
Wissenschaften, A-6020 Innsbruck, Austria
The tremendous success of the ¯eld of ultracold atomic gases has triggered the quest for
ultracold molecular gases. The production of such molecular gases was hindered by the
absence of standard laser cooling techniques for molecules because of their richer internal
structure. Other pathways to cold and dense samples of molecules such as sympathetic
cooling or association of ultracold atoms are required. Association via Feshbach reso-
nances has already led to quantum degenerate or nearly quantum degenerate ultracold
molecular gases, but only in very weakly bound states with high vibrational quantum
numbers. Such molecules are in general unstable under collisions with each other.
We overcome this limitation by optically transferring weakly bound Rb2 Feshbach molecules
to the intrinsically more stable ro-vibrational ground state of the triplet potential. The
transfer is carried out in a single step using stimulated Raman adiabatic passage (STI-
RAP) with an e±ciency of about 60%, which is only technically limited. Because we
begin with a nearly quantum degenerate gas of Feshbach molecules, we thus enter for the
¯rst time the regime of an ultracold and dense ensemble of tightly bound molecules. The
molecules which are held in a 3D optically lattice exhibit a lifetime longer than 100 ms.
These results open the door for a new generation of experiments with tightly bound ultra-
cold molecules allowing for investigations of ultracold collisions and chemistry, production
of a molecular BEC, as well as molecular quantum optics.
PR 5
17
Manipulating cold molecular gases with intense
optical elds
P. F. Barker
Department of Physics and Astronomy, University College London
Over last few years we have been exploring the application of intense, far o -resonant,
optical elds for manipulating the centre-of-mass motion of molecular gases using large
optical potentials in the 100 K range. This unique means of control, which can be applied
to essentially any gas, has been used to decelerate molecular beams from supersonic speeds
to rest to creating cold stationary molecular ensembles. Using these tailored light elds we
have also focused molecular beams to micron dimensions and have even brie y trapped
room temperature gases. In this update I will review these experiments and describe
more recent work, which is studying the role of laser-induced molecular alignment on the
manipulation of molecules, and also the trapping and sympathetic cooling of molecules
with ultracold atoms.
PR 6
18
Resonant laser spectroscopy in the soft X-ray region
Jos e R. Crespo L opez-Urrutia, S. W. Epp, and J. Ullrich
Max Planck Institute for Nuclear Physics,
Saupfercheckweg 1, 69117 Heidelberg, Germany
In vast regions of the universe highly charged ions (HCI) are the predominant form of
visible matter. They also appear in nuclear fusion devices as well as in high-temperature
laser produced plasmas. Yet, their electronic structure still remains a challenge for both
theory and experiment. As a result of the limitations of traditional spectroscopic methods
in the soft and hard x-ray regions, accuracy currently constrains our knowledge of quantum
electrodynamics (QED) in strong elds. The application of laser spectroscopy to such
studies, which in the visible and ultraviolet range has already led to the most comprehensive
veri cation of a physical theory, QED, in weak elds, being even capable of testing
the time drift of fundamental constants, was until now not possible due to the lack of
appropriate light sources. Extending such precision tests to strong elds beyond perturbation
theory has general implications for the formalism of other quantum eld theories,
nuclear physics and parity-non-conservation studies. In our experiment [1], HCIs stored
in an electron beam ion trap(EBIT) were excited by tunable ultra-intense soft x-rays generated
at the Free electron LASer in Hamburg (FLASH), the rst free electron laser in
the world operating in that spectral range. With this setup, resonant laser excitation of
bound-bound electronic transitions, namely the 1s22s 2S1=2 to 1s22p 2P1=2;3=2 lines of the
Li-like Fe23+ ion at 48.6 and 65.5 eV and of the isoelectronic Cu26+, became possible in
an energy range hitherto unattainable with powerful lasers. This and more recent experiments,
yielding a relative statistical error of only 2 ppm corresponding to 0.1% of the QED
contributions, demonstrate immediate potential to push the current limits of precision by
up to three orders of magnitude. They allow for tests of the QED theory in a regime in
which standard perturbation methods fail, in the environment of the highest stationary
electromagnetic elds found in nature, in the vicinity of the nucleus. Future experiments
at upcoming x-ray free electron lasers (X-FEL) like the Stanford Linear Coherent Light
Source (LCLS) or the European X-FEL will pave the way into the hard x-ray region, at
energies appropriate for even deeper probing of strong eld QED e ects. Investigations of
the photoionization of HCI and precision determinations of the lifetimes of excited states
are possible with this EBIT method. It will also allow establishing atomic frequency
standards at these high photon energies by coupling laser emission by e.g. high-harmonic
generation directly to bound-bound transitions of { ideally { hydrogen-like ions, overcoming
the present uncertainties found in x-ray standards derived from solid-state samples.
[1] S.W. Epp, J. R. Crespo L opez-Urrutia, G. Brenner, V. Mackel, P. H. Mokler, R.
Treusch, M. Kuhlmann, M. V. Yurkov, J. Feldhaus, J. R. Schneider, M. Wellhofer, M.
Martins, W. Wurth, and J. Ullrich, Phys. Rev. Lett 98, 183001 (2007)
PR 7
19
Resonances in Rare Gas Atoms:
Many-Electron Theory and Experiment
V. L. Sukhorukov
Rostov State University of Transport Communications,
344038 Rostov-on-Don, Russia
E-mail: vls@rgups.ru
Excitation processes in the rare gas atoms Ne, Ar, Kr and Xe with energies between the
two lowest ionization thresholds mp5
3=2 and mp5
1=2(m = 2¡5) are dominated by resonances
stemming from mp5
1=2n`0[K]J autoionizing Rydberg states (ARS). These states provide
very suitable objects for the investigation of many-electron e®ects, both outside the atomic
core, where the n`0- electron is localized, and inside the core, which is responsible for the
lifetime of the ARS. Starting with the pioneering work of Beutler [1] these resonances
have been intensively studied experimentally (see, e.g. [2{5]). The two main properties
of the resonances which are derived from experimental spectra are the quantum defect
¹`, which determines the resonance energy, and the autoionization width ¡n, i.e. the
resonance lifetime ¿n = ~=¡n.
In this talk we focus on the in°uence of many-electron e®ects on the processes responsible
for the excitation and decay of the ARS. The lineshapes used for the evaluation of ¹` and
¡n are strongly dependent on the level from which the ARS are excited. In order to gain
detailed insight into the dynamics for excitation and decay of the ARS, we applied the
con¯guration interaction Pauli-Fock approach including the e®ects of core polarization
(CIPFCP) [6,7]. Using the CIPFCP method, we calculated resonance parameters (¹`,
¡n) [4,8,9] and the absolute photoionization cross sections (including the lineshapes) [5,9{
11] for a broad range (`0 = 0 ¡ 5) of the autoionizing resonances in the rare gas atoms
Ne-Xe. By comparing measured ARS lineshapes with the computed pro¯les and adopting
step-by-step inclusion of many electron e®ects in the calculations, the important types of
electron correlations are identi¯ed.
Support of this work by the Deutsche Forschungsgemeinschaft is gratefully acknowledged.
References
[1] H. Beutler, Z. Phys. 93, 177 (1935).
[2] J. Berkowitz, Adv. Chem. Phys. 72, 1 (1988).
[3] H. Hotop, D. Klar, and S. Schohl, Proc. 6th Int. Symp. on Resonance Ionization
Spectroscopy (RIS-92) volume 128 of Inst. Phys. Conf., 45 (1992).
[4] I. D. Petrov, V. L. Sukhorukov, and H. Hotop, J. Phys. B 35, 323 (2002).
[5] I. D. Petrov et al J. Phys. B 39, 3159 (2006).
[6] I. D. Petrov, V. L. Sukhorukov, and H. Hotop, J. Phys. B 32, 973 (1999).
[7] I. D. Petrov et al Eur. Phys. J. D 10, 53 (2000).
[8] I. D. Petrov, V. L. Sukhorukov, and H. Hotop, J. Phys. B 36, 119 (2003).
[9] T. Peters et al J. Phys. B 38, S51 (2005).
[10] I. D. Petrov et al Eur. Phys. J. D 40, 181 (2006).
[11] I. D. Petrov, V. L. Sukhorukov, and H. Hotop, J. Phys. B 41, 065205 (11pp) (2008).
PR 8
20
Attosecond spectroscopy in atoms and solids
Reinhard Kienberger
Max-Planck-Institut f¨ur Quantenoptik, Hans-Kopfermann-Straße 1, D-85748 Garching
The generation of ever shorter pulses is a key to exploring the dynamic behavior of matter
on ever shorter time scales. Over the past decade novel ultrafast optical technologies
have pushed the duration of laser pulses close to its natural limit, to the wave cycle,
which lasts somewhat longer than one femtosecond (1 fs = 10􀀑15 s) in the visible spectral
range. Time-resolved measurements with these pulses are able to trace atomic motion
in molecules and related chemical processes. However, electronic dynamics inside atoms
often evolve on an attosecond (1 as = 10􀀑18 s) timescale and require sub-femtosecond
pulses for capturing them. Atoms exposed to a few oscillation cycles of intense visible
or near-infrared light are able to emit a single electron and XUV photon wavepacket of
sub-femtosecond duration [1, 2]. Precise control of these sub-femtosecond wavepackets
have been achieved by full control of the electromagnetic field in few-cycle light pulses
[3]. These XUV pulses together with the few-cycle (few-femtosecond) laser pulses used for
their generation have opened the way to the development of a technique for attosecond
sampling of electrons ejected from atoms or molecules [4]. This is accomplished by probing
electron emission with the oscillating electric field of the few-cycle laser pulse following
excitation of the atom by the synchronized sub-femtosecond XUV pulse. Sampling the
emission of photo electrons in this manner allows time-resolved measurement of the XUV
pulse duration as well as of the laser field oscillations [5]. After the full characterization of
these tools, first experiments have been carried out to measure sub-femtosecond behavior
of matter. Recently, the dynamics of the photoionization process on solids has been studied
[6]. Not only that attosecond metrology now enables clocking on surface dynamics,
but also the individual behaviour of electrons of di􀀦erent type (core electrons vs. conduction
band electrons) can be resolved. Here, we measured a time delay of about 100
as on the emission of the aforemention two types of electrons. The information gained in
these experiments may have influence on the development of many modern technologies
including semiconductor and molecular electronics, optoelectronics, information processing,
photovoltaics, electronically stimulated chemistry on surfaces and interfaces, optical
nano-structuring, and interference e􀀦ects in spectroscopy.
References
[1] M. Hentschel et al., Nature 501 (2001).
[2] R. Kienberger et al. Science 297, 1144 (2002).
[3] A. Baltuska et al., Nature 421, 611 (2003).
[4] R. Kienberger et al., Nature 427, 817 (2004).
[5] E. Goulielmakis et al. Science 305, 1267 (2004).
[6] A. Cavalieri et al., Nature 449, 1029 (2007).
PR 9
21
Above, Around, and Below Threshold Ionization
using Attosecond Pulses
Johan Mauritsson¤
Department of Physics, Lund University, P.O. Box 118, SE-221 00 Lund, Sweden
Attosecond pulses o®er a new route to produce temporally localized electron wave packets
that can easily be tailored by altering the properties of the attosecond pulses. In this talk
we will present three di®erent experiments where attosecond pulses are used to inject
electron wave packets into a continuum which is dressed by an infrared laser ¯eld. By
tuning the central frequency of the attosecond pulses and/or changing the target gas, the
initial energy of the wave packets is set to be either above, around, or below the ionization
potential.
To capture the motion of electron wave packets created above or around the ionization
potential we have developed a quantum stroboscope to record the electron momentum
distribution from a single ionization event. The quantum stroboscope is based on a
sequence of identical attosecond pulses that are used to release electrons into a strong
laser ¯eld exactly once per laser cycle. With this periodicity, the pulses create identical
electron wave packets that add up coherently, with the result that the properties of an
individual wave packet can be studied stroboscopically. We use this technique to study
the coherent electron scattering of electrons that are driven back to the ion by the laser
¯eld [1].
For electron wave packets created below the ionization potential we ¯nd that the ionization
is greatly enhanced by the presence of the infrared laser ¯eld and that this enhancement
strongly depends on the timing between the attosecond pulses and the laser ¯eld. We
show that this e®ect can be attributed to interference between consecutive wave packets,
which indicates that the wave packets stay in the vicinity of the ion over an extended
time period [2].
Using instead isolated attosecond pulses generated from an ultrashort, carrier-envelope-
phase stabilized infrared laser with a time-dependent polarization [3] we show that it is
possible to also probe ultrafast bound electron dynamics. These attosecond pulses are
broad enough to excite coherently all the p-states in Helium and a fraction of the contin-
uum. The wave packets created in Helium, partly trapped in the atomic potential, are
probed by a 7 fs 750 nm infrared laser ¯eld, with an intensity of 3 £ 1012 W/cm2. Using
this method we can extract the amplitudes and the phase evolutions of the bound, excited
states.
¤ Part of the work was done in collaboration with LSU, AMOLF, MPQ and CUSBO.
References
[1] J. Mauritsson et al., Phys. Rev. Lett. 100, 073003 (2008).
[2] P. Johnsson et al., Phys. Rev. Lett. 99, 233011 (2007).
[3] G. Sansone et al., Science 314, 443 (2006).
PR 10
22
Few-body physics with ultracold Cs atoms and
molecules
F. Ferlaino, S. Knoop, M. Mark, M. Berninger, H. SchÄobel, H. C. NÄagerl, and R. Grimm
Institut fr Experimentalphysik, Innsbruck, Austria Institut fr Quantenoptik und
Quanteninformation, Innsbruck,Austria
Ultracold gases are versatile systems to study few-body physics because of full control
over the external and internal degrees of freedom. Scattering properties can be controlled
because of the magnetic tunability of the two-body scattering length in the proximity of a
Feshbach resonance and weakly bound dimers can be produced. Here we experimentally
study three- and four-body physics by investigating ultracold (30-250 nK) atom-dimer
and dimer-dimer collisions with Cs Feshbach molecules in various molecular states and Cs
atoms in di®erent hyper¯ne states. Resonant enhancement of the atom-dimer relaxation
rate is observed in a system of three identical bosons and interpreted as being induced
by a trimer state, possibly an E¯mov state. A strong magnetic ¯eld dependence of the
relaxation rate is also observed in a atom-dimer mixture made of non-identical bosons.
Dimer-dimer inelastic collisions have been studied in a pure, trapped sample of Feshbach
dimers in the quantum halo regime. We identify a pronounced loss minimum with varying
scattering length along with a further suppression of loss with decreasing temperature.
This observations provide insight into the physics of a few-body quantum system that
consists of four identical bosons at large values of the two-body scattering length.
CP 1
23
Weakly bound molecules : Analysis by the Lu-Fano method
coupled to the LeRoy-Bernstein model.
Haikel Jelassi, Bruno Viaris de Lesegno, Laurence Pruvost
Laboratoire Aimé Cotton, CNRS II, bat 505, campus d’Orsay
91405 Orsay, France
E-mail: laurence.pruvost@lac.u-psud.fr
We have performed experiments on photo-association spectroscopy of cold 87Rb atoms,
below the (5s1/2+5p1/2) dissociation limit. By applying the trap loss spectroscopy method
[1] we have measured the binding energies of the weakly bound molecules, associated to
the 0−
g , 0+
u and 1g symmetries.
Such weakly bound molecules are described by the dipole-dipole atom interaction which
varies, according to the molecular symmetry, either as 1/R3 or as 1/R6, where R is
the inter-nuclear distance. The eigen energies of the weakly bound molecules are then
very close to those obtained by the well-known Le Roy-Bernstein (LRB) model [2]. The
discrepancies to the LRB law are due to the short distance behavior of the molecular
potentials or to couplings between molecular potentials resulting from interactions, for
example spin-orbit or spin-spin interactions.
To analyze the data, we have adapted the Lu-Fano (LF) method - well-known for Rydberg
atoms - to the weakly bound molecules. Using the LRB law, a molecular quantum defect
is defined and deduced from the data. The LF graph - quantum defect versus the binding
energy - allows us to characterize the molecular potential and the couplings.
For the 0−
g molecular levels, we observe a linear LF graph, which is the signature of the
short range behavior of the molecular potential. A model for the barrier allows us to
connect the slope to the barrier location [3]. The method has also been applied to 85Rb
and 133Cs [4].
For 0+
u molecular levels, the LF graph exhibits sharp variations which indicate a coupling
with a neighboring molecular series. The coupling is due to the spin-orbit interaction
in the molecule. A two series model allows us to evaluate the coupling, to identify two
perturbing levels of the (5s1/2+5p3/2) 0+
u series and to predict the energy position and the
width of its first pre-dissociated level. An experimental signal agrees with the prediction
[4]. The method has also been successfully applied to 133Cs.
References
[1] P. D. Lett et al., Phys. Rev. Lett. 71, 2200 (1993)
[2] R. J. Le Roy, R. B. Bernstein, J. Chem. Phys. 52, 3869 (1970)
[3] H. Jelassi, B. Viaris De Lesegno, L. Pruvost, Phys. Rev. A. 73, 32501 (2006)
[4] H. Jelassi, B. Viaris De Lesegno, and L. Pruvost, AIP Conference Proceedings, ISC
2007, 935, 203, (2007)
[5] H. Jelassi, B. Viaris De Lesegno, L. Pruvost, Phys. Rev. A. 74, 12510 (2006)
CP 2
24
Calculations of static polarizabilities of alkali dimers
and alkali hydrides. Prospects for alignment of
ultracold molecules.
Mireille Aymar,+, Johannes Deiglmayr¤, and Olivier Dulieu +
+Laboratoire Aim¶e Cotton, CNRS and Univ Paris Sud, B^at. 505,91405 Orsay Cedex,
France
¤ Physikalisches Institut, UniversitÄat Freiburg, Hermann-Herder-Strasse 3, 79104
Freiburg, Germany.
The rapid development of experimental techniques to produce ultracold alkali molecules
opens the ways to manipulate them and to control their dynamics using external electric
¯elds. A prerequisite quantity for such studies is the knowledge of their static dipole
polarizabilities.
We computed the variations with internuclear distance and with vibrational index of the
static dipole polarizability components of all homonuclear alkali dimers including Fr2, and
of all heteronuclear alkali dimers involving Li to Cs, in their electronic ground state and
in their lowest triplet state and of alkali hydrides LiH to CsH in their ground state. We
use the same quantum chemistry approach than in our work on dipole moments [1] based
on pseudopotentials for atomic core representation, Gaussian basis sets, and e®ective
potentials for core polarization. Polarizabilities are extracted from electronic energies
using the ¯nite-¯eld method [2].
For the heaviest species Rb2, Cs2 and Fr2 and for all heteronuclear alkali dimers and for
CsH, such results are presented for the ¯rst time. The accuracy of our results on atomic
and molecular static dipole polarizabilities is discussed by comparing our values with the
few available experimental data and elaborate calculations. We found that for all alkali
pairs, the parallel and perpendicular components of the ground state polarizabilities at the
equilibrium distance Re scale as (Re)3. Prospects for possible alignment and orientation
e®ects with these molecules in forthcoming experiments are discussed.
[1] M. Aymar and O. Dulieu, J. Chem. Phys 122, 204302(2005).
[2] J. Deiglmayr, M. Aymar, M. WeidemÄuller, R. Wester, and O. Dulieu, submitted to J.
Chem. Phys.
CP 3
25
Electrostatically extracted cold molecules from a
cryogenic bu®er gas
Laurens D. van Buuren, Christian Sommer, Michael Motsch, Markus Schenk,
Pepijn W.H. Pinkse, and Gerhard Rempe
Max-Planck-Institut fÄur Quantenoptik,
Hans-Kopfermann-Str. 1, 85748 Garching, Germany
Dense samples of cold polar molecules o®er new perspectives in physics [1]. Studies of
cold collisions and chemical reactions as well as high precision measurements will bene¯t
from these samples. For this kind of studies there is still need for new sources which
deliver a high density and a high °ux of cold molecules.
We present a source which delivers a continuous, high-density beam of slow and internally
cold polar molecules. In the source, warm molecules are injected into a cryogenic cell,
in which their external and internal degrees of freedom are cooled by collisions with a
helium bu®er gas [2]. Cold molecules are extracted out of the cryogenic environment by
means of an electric quadrupole guide. Information on the state purity of the extracted
beam is obtained by laser depletion of H2CO within the guide [3]. In future, the beam
can be loaded into a large volume electrostatic trap (as previously shown [4]) to perform
for example collision experiments.
References
[1] J. Doyle, B. Friedrich, R. V. Krems and F. Masnou-Seeuws, Eur. Phys. J. D 31, 149
(2004).
[2] J. Weinstein, R. DeCarvalho, T. Guillet, B. Friedrich and J. Doyle, Nature (London)
395, 148 (1998).
[3] M. Motsch, M. Schenk, L.D. van Buuren, M. Zeppenfeld, P.W.H. Pinkse, and G.
Rempe, Phys. Rev. A 76, 061402R (2007).
[4] T. Rieger, T. Junglen, S.A. Rangwala, P.W.H. Pinkse, and G. Rempe, Phys. Rev.
Lett. 95, 173002 (2005).
CP 4
26
In-situ non-invasive quality control of packaged meat
using a micro-system external cavity diode laser at
671 nm for Raman spectroscopy
Heinz-Detlef Kronfeldt1, Heinar Schmidt1, Bernd Sumpf2, Martin Maiwald2,
Götz Erbert2, Günther Tränkle2
1Technische Universität Berlin, Institut für Optik und Atomare Physik
Sekr. EW 0-1, Hardenbergstr. 36, 10623 Berlin, Germany
2Ferdinand-Braun-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Straße 4,
12489 Berlin, Germany
Diode lasers are highly attractive for spectroscopic field applications where small sizes and
low power consumption are prerequisites. They are available as light sources from the blue
up to the mid infrared spectral range and are commonly used in sensor systems. However,
in the ultraviolet and visible spectral ranges, which are of special interest to fluorescence
and Raman spectroscopy, compact diode laser based devices with narrow spectral width
are not commercially available.
In this presentation, we will show how micro-system technology can overcome these problems
with a small size high power external cavity diode laser (ECDL) emitting at 671nm
with a small emission width suitable for Raman spectroscopy. All elements used in these
devices are mounted on micro optical benches with a dimension of only (13 x 4 x
1)mm3. For our experiments the subassemblies were mounted on conduction cooled packages
(CCP) with footprints of only (25 x 25)mm2.
The ECDL system includes a broad area device as gain material, micro-optics for beam
shaping and a reflecting Bragg grating for wavelength stabilization. We present results for
devices with an output power of 200mW and a stable emission at 671 nm. The spectral
width of = 80pm ( ˜ 2 cm−1), which includes 95% of intensity fits within the
required spectral width of = 450pm ( ˜ 10 cm−1) for Raman bands of most liquid
and solid samples.
This micro-system laser device is implemented into a specifically designed Raman sensor
for in-situ measurements of meat. Raman spectroscopy offers the advantages to measure
non invasive and through the packaging. The sensor exploits the fingerprinting characteristics
of Raman spectra for substance identification and to follow the physicochemical
and biochemical changes upon aging of meat products.
The Raman probe is characterized and first results of time-dependent Raman measurements
of porcine musculus longissimus dorsi aged for up to 4 weeks at 5 C will be
presented. The usefulness of Raman spectroscopy will be discussed with a view of integrating
the sensor in a handheld laser scanner for food control.
This work was supported by the BMBF funded project „FreshScan“ 16SV2332.
CP 5
27
3H/3He mass ratio experiment MPIK/UW-PTMS in
the context of º-mass measurements
David Pinegar1, Christoph Diehl1, Robert Van Dyck, Jr.2, and Klaus Blaum1
1Max-Planck-Institut fÄur Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg, Germany
2Department of Physics, University of Washington, Seattle, WA 98195-1560, USA
e-mail: pinegar@mpi-hd.mpg.de
Beta-spectrometer experiments to constrain neutrino masses (such as KATRIN [1] and
the completed Mainz experiment [2]) have a long history, as do independent helium¡3 and
tritium mass di®erence measurements like the most precise result from SMILETRAP [3].
The main goal of MPIK/UW-PTMS, the Max-Planck-Institute for Nuclear Physics / Uni-
versity of Washington Penning Trap Mass Spectrometer collaboration, is to use simulta-
neous axial-frequency-lock in two externally-loaded hyperbolic Penning traps to perform
single-ion cyclotron frequency measurements for a determination of the 3H to 3He mass
ratio with 10¡11 uncertainty. Ideally their mass di®erence (which is easily calculated
from the mass ratio) will be found with an uncertainty much smaller than the tritium
¯-spectrum endpoint can be determined by the KATRIN experiment. For KATRIN, the
uncertainty on the endpoint depends on absolute calibration of the spectrometer retard-
ing potential as well as several other factors. Because mechanisms causing systematic
uncertainty in beta-spectrometers generally e®ect both the ¯tted endpoint E0 and the
¯tted electron neutrino mass mº, agreement between the spectrum endpoint and inde-
pendent mass di®erence measurements should reinforce con¯dence in the understanding
of KATRIN systematic uncertainties. Hopefully, in the future agreement at the » 50 meV
level will be found, just as good agreement was found at the » 2 eV level between earlier
3H to 3He mass di®erence measurements and beta-spectrometers of lower resolution than
KATRIN.
References
[1] J. Angrik, et al., FZKA Scienti¯c Report 7090, MS-KP-0501, (2004).
[2] Ch. Kraus, et al., Eur. Phys. J. C, 40, 447{468, (2005).
[3] Sz. Nagy, et al., Europhys. Lett., 74, 404{410, (2006).
CP 6
28
Optical microtraps for cold atoms based on near-¯eld
di®raction
S. Nic Chormaic1;2, T. N. Bandi2;3 and V. Minogin2;3;4
1Physics Department, University College Cork, Cork, Ireland
2Photonics Centre, Tyndall National Institute, Prospect Row, Cork, Ireland
3Dept. of Applied Physics and Instrumentation, Cork Institute of Technology,
Bishopstown, Cork, Ireland
4Institute of Spectroscopy, Russ. Ac. of Sciences, 142190 Troitsk, Moscow Region,
Russia
E-mail: S.NicChormaic@ucc.ie
In recent years there has been signi¯cant interest in studies on the development of neutral
atom traps and the applications thereof [1-4]. One novel approach to the development
of miniature atom traps involves the optical near-¯elds formed by laser di®raction on an
array of circular apertures in a thin screen [5]. This approach can be adapted in order
to fabricate an array of atom microtraps and, accordingly, produce a large number of
trapped atomic microensembles from a single initial atomic cloud or beam.
In this paper, we propose and analyze such near-¯eld Fresnel-type atom microtraps with
a characteristic aperture size approximately equal to the optical wavelength incident on
the thin screen. Our analysis of the atom microtraps shows that, for a moderate laser
intensity of about 10 W/cm2, the traps can store atoms with a kinetic energy equivalent
to » 100¹K, and with estimated lifetimes of » 1 second.
Our analysis for 85Rb and 133Cs atoms shows that the potential well depth of the micro-
traps is mainly determined by the intensity of the incident laser ¯eld and the detuning.
By varying these two parameters one can achieve robust control over the trap param-
eters. The incident laser intensity of 10 W/cm2 corresponds to about 0.5 ¹W of laser
power incident on each individual aperture. With such trap parameters one can perform
atom optics experiments by blending microfabrication technology with cold atoms for site
selective addressing of microtraps.
References
[1] V. I. Balykin, V. G. Minogin, and V. S. Letokhov, Rep. Prog. Phys. 63, 1429 (2000)
[2] W. HÄansel, P. Hommelho®, T. W. HÄansch, and J. Reichel, Nature 413, 498 (2001)
[3] S. K. Sekatskii, B. Riedo, and G. Dietler, Opt. Comm. 195, 197 (2001)
[4] K. D. Nelson, X. Li, and D. S. Weiss, Nat. Phys. 3, 556 (2007)
[5] V. I. Balykin and V. G. Minogin, Phys. Rev. A 77, 013601 (2008).
CP 7
29
Optical Spectroscopy of Rubidium Rydberg Atoms
with a 297nm Frequency Doubled Dye Laser
Th. Becker, Th. Germann, P. Thoumany, G. Stania, L. Urbonas and T. H¨ansch
Max Planck Institute for Quantum Optics
Hans Kopfermann Str. 1
85748 Garching, Germany
Rydberg atoms have played an important role in atomic physics and optical spectroscopy
since many years. Due to their long lifetime and the big dipole matrix element between
neighbouring Rydberg levels they are an essential tool in microwave cavity-qed
experiments. Ultracold Rydberg gases are a promising candidate for realizing controlled
quantum gates in atomic ensembles. In most experiments Rydberg atoms are detected
destructively, where the optically excited atoms are first ionized followed by an electronic
detection of the ionization products. A Doppler-free purely optical detection was reported
in [1] in a room temperature cell and in [2] in an atomic beam apparatus using the technique
of electromagnetically induced transparency. In all these experiments the Rydberg
atoms are excited with two lasers in a two-step ladder configuration.
Here we show that Doppler-free purely optical spectroscopy is also possible with a one
step excitation scheme involving a UV laser at 297 nm. We excite the 85Rb isotope from
the 5S1/2 ground state to the 63P3/2 state with a frequency doubled dye laser in a room
temperature gas cell without buffer gas. Rydberg transitions are detected by monitoring
the absorbtion of 780 nm laser light which is superimposed on the UV light and resonant
with one hyperfine component of the Rubidium D2 line. With these two lasers we realize a
V-scheme and utilize the quantum amplification effect due to the different natural lifetimes
of the upper levels of the two transitions: an excitation into the 63P level hinders many
absorbtion-emission cycles of the D2 transition and leads to a reduced absorption on that
line. We discuss the shape of the observed spectra in the context of electron shelving and
EIT experiments.
By applying a frequency modulation to the UV laser, we can obtain dispersive signals
which can be used to stabilize the laser to a specific Rydberg transition. By shifting
the frequency of the 780 nm laser to crossover resonances in the saturated absorbtion
spectrum of the D2 line, the stabilization point of the UV laser can be detuned from
the resonance by discrete values. Using this idea, we demonstrate the stability of the
frequency locking scheme with an atomic beam apparatus: if the detuned laser hits the
atomic beam under a small angle, only atoms of a certain velocity class will be transferred
to their upper level. We excite the atoms with pulses of 5 μsec duration and measure
their arrival times 10 cm behind the excitation region with field selective ionization. By
analyzing the time of flight spreading we can show that the long-term linewidth of the
laser is below 2 MHz in the UV, which corresponds to the specified short time stability
of the dye laser and the long term frequency drift can be effectively compensated.
references:
[1] A. K. Mohpatra, T. R. Jackson, C. S. Adams, Phys. Rev. Lett. 98, 113003 (2007).
[2] S. Mauger, J. Millen and M. P. A. Jones, J. Phys. B: At. Mol. Opt. Phys. 40, F319
(2007).
CP 8
30
Helium n1;3S excited states obtained with an angular
correlated con¯guration interaction method
K. V. Rodriguez1;4, V. Y. Gonzalez1;4, L. U. Ancarani2, D. M. Mitnik3;4
and G. Gasaneo1;4
1Departamento de F¶³sica - Universidad Nacional del Sur, 8000 Bah¶³a Blanca, Argentina
2Laboratoire de Physique Mol¶eculaire et des Collisions,
Universit¶e Paul Verlaine - Metz, France
3Instituto de Astronom¶³a y F¶³sica del Espacio, y Departamento de F¶³sica, Facultad de
Ciencias Exactas y Naturales, Universidad de Buenos Aires. C.C. 67, Suc. 28,
(C1428EGA) Buenos Aires, Argentina
4Consejo Nacional de Investigaciones Cient¶³¯cas y T¶ecnicas, Argentina
We construct approximate helium wavefunctions for ground and excited n1;3S states
through the angular correlated con¯guration interaction (ACCI) method proposed in [1].
The trial wavefunctions are given by
ªC3¡N =
X
n1;n2;n3
'n1(r1)'n2(r2)ÂC3(n12; r12)
X
ijk6=1
cn1n2n12
ijk ri
1rj
2rk
12
where r1; r2; r12 are the interparticle coordinates. The products 'n1(r1)'n2(r2)ÂC3(n12; r12)
(with (n1; n2; n12 integers) were proposed by Gasaneo and Ancarani in [2] as parameter-
free basis functions: 'ni are l = 0 hydrogenic functions, and ÂC3 = 1F1(¡n12; 2;¡r12=n12)
is the angular correlation factor [2,3] which results from the analytic continuation of the
widely used double continuum three-body Coulomb (C3) wave function [4]. Each of these
product satis¯es exactly all two-body Kato cusp conditions. Following the methodology
proposed in [1], we multiply each of them by a series which does not a®ect this property.
The trial wavefunction involves then N linear variational parameters cn1n2n12
ijk which are
obtained by solving a generalized eigenvalue problem. The n1;3S states obtained in this
way form an orthogonal set of wavefunctions.
Quite accurate energies values for both the ground and excited states can be obtained
with only a relatively low number of terms, as illustrated by the following table (the
construction includes the 1s1s; 1s2s and 1s3s multiple con¯gurations and n12 up to 2).
N n1 n2 n12 ¡E11S ¡E23S ¡E21S ¡E33S
24 1,2 1,2 1,2 2.90329 2.1752 2.14587 2.05589
38 1,2,3 1,2,3 1,2 2.90335 2.17521 2.14594 2.06866
52 1,2,3,4 1,2,3,4 1,2 2.90339 2.17522 2.14594 2.06869
Exact[5] 2.90372 2.17523 2.14597 2.06869
References
[1] K.V. Rodriguez, G. Gasaneo and D.M. Mitnik, J. Phys. B 40 (19), 3923 (2207).
[2] G. Gasaneo and L.U. Ancarani, Phys. Rev. A 77, 012705 (2008)
[3] L.U. Ancarani and G. Gasaneo, Phys. Rev. A 75, 032706 (2007)
[4] C.R. Garibotti and J.E. Miraglia, Phys. Rev. A 21, 572 (1980)
[5] G.W.F. Drake (ed) 2005 Springer Handbook of Atomic, Molecular, and Optical Physics
CP 9
31
Atomic structure calculations of Cm+4 and Am+3 ions
G. Gaigalas1
,
2, E. Gaidamauskas1 and Z. Rudzikas1
1Vilnius University Research Institute of Theoretical Physics and Astronomy,
A. Goˇstauto 12, LT-01108 Vilnius, Lithuania
2Vilnius Pedagogical University, Student¸u 39, LT-08106, Vilnius, Lithuania
E:mail:gaigalas@itpa.lt
Modern technologies require knowledge of atomic structure of the most complex chemical
elements, actinides included. The accuracy of the results obtained depends on the degree
of accounting for correlation and relativistic effects. Many phenomena or properties, e.g.
effective magnetic moments of the Cm
+4 ions measured in several compounds [1], still
remain unexplained. In this report we present ab initio calculations of the lowest energy
terms and levels of Cm
+4 and Am
+3 ions in nonrelativistic approach.
For the calculation of energy spectra of Cm
+4 and Am
+3 ions we used multiconfigurational
Hartree-Fock and configuration interaction methods accounting for relativistic efects in
Breit-Pauli approach. Configuration state functions of the multiconfiguration expansion
additionally include single and double substitutions from the valence shell (VV correla-
tions). All calculations were performed with the MCHF atomic-structure package [2]. The
dependence of fine structure of the lowest term 7
F of Cm
+4 in Breit-Pauli approach on
correlation effects taken into consideration is presented in Table. The results obtained
demonstrate that core-valence and core-core correlations are essential for the Cm
+4 and
Am
+3 term energy, whereas their role in the case of fine structure is much less compared
to that of valence-valence correlations. Therefore the latters must be accounted for while
studying the fine structure of the ions. The calculated energy levels of the Cm
+4 are in
a good agreement with experimentally obtained values [3].
Table I. The lowest 7 energy levels of Cm
+4 in MCHF+BREIT (CI) approach with dif-
ferent degree of accounting for correlation effects.
States Energy Level (cm−1)
AS6 AS7 AS8 AS9 AS10 AS11 AS12
5f
6 7
F0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
7
F1 1788.0 2019.5 2105.6 2196.5 2225.6 2265. 4 2292.6
7
F2 4838.0 5464.5 5691.9 5935.8 6012.4 6118. 0 6182.9
7
F3 8188.9 9221.8 9566.6 9960.9 10079.6 10248. 2 10340.5
7
F4 11107.3 12422.6 12797.1 13284.9 13422.3 13628. 0 13728.3
7
F5 13656.3 15143.0 15492.3 16029.8 16171.7 16396. 2 16494.6
7
F6 16117.2 17681.3 17974.2 18527.4 18664.4 18894. 1 18983.6
References
[1] S.E. Nave, R. G. Haire, P.G. Huray, Phys. Rev. B. 28, 2317 (1983)
[2] C. Froese Fischer, G. Tachiev, G. Gaigalas, M.R. Godefroid, Comput. Phys. Comm.
176, 559 (2007)
[3] G.K. Liu, J.V. Beitz, Phys. Rev. B. 41, 6201 (1990)
CP 10
32
MCDHF calculations of the electric dipole moment
of radium induced by the nuclear Schiff moment
E. Gaidamauskas1, G. Gaigalas1, J. Bieron2, S. Fritzsche3 and P. J¨onsson4
1Vilnius University Research Institute of Theoretical Physics and Astronomy,
A. Goˇstauto 12, LT-01108 Vilnius, Lithuania,
2Instytut Fizyki imienia Mariana Smoluchowskiego, Uniwersytet Jagiello´nski
Reymonta 4, 30-059 Krak´ow, Poland
3Gesellschaft f¨ur Schwerionenforschung Darmstadt, Planckstr.1, D-64291 Darmstadt,
Germany
4Nature, Environment, Society Malm¨o University, S-205 06 Malm¨o, Sweden
E-mail:gaigalas@itpa.lt
A non-zero permanent electric dipole moment (EDM) of atom, molecules or other composite
or elementary particle is one of possible manifestations of parity (P) and time
reversal (T) symmetry violations. During the last decade, several atoms were considered
as candidates for such experiments, and currently radium appears to be the most promising
one. Experiments with radium are underway in Argonne National Laboratory and in
Kernfysisch Versneller Instituut. The multiconfiguration Dirac-Hartree-Fock theory has
been employed to calculate the electric dipole moment of the metastable 7s6d
3
D2 state
of radium. One of the most important parity and time reversal symmetry violating interaction
in atoms is due to a possible Schiff moment between the electrons and the nucleus:
ˆH
SM = 4
N
X
j
=1
(S ·∇
j) (r
j) . (1)
This interaction mixes parity of atomic states and also induces a static electric dipole
moment of the atom. For the calculations of the Schiff moment interaction and electric
dipole moment operators matrix elements we extended the GRASP2K relativistic atomic
structure package [1]. In the calculations valence and core-valence electron correlation
effects have been included in a converged series of multiconfiguration expansions. In this
contribution, we investigate the mixing of two atomic levels of opposite parity, 7s7p
3
P1
and 7s6d
3
D2, which are separated by a very small energy interval 5cm
−1. The calculated
values of EDM are presented in the Table. Obtained results are in a good agreement with
other theories [2].
Table 1: EDM for different isotopes of Ra in the 3
D2 state induced by the Schiff moment.
223
88
Ra I = 3
2
F = 3
2
225
88
Ra I = 1
2
F = 3
2
MCDHF RHF+CI [2] MCDHF RHF+CI [2]
0.43 × 109
IS 0.30 × 109
IS 1.40 × 108
IS 0.94 × 108
IS
References
[1] P. J¨onsson, X. He, C. Froese Fischer, I.P. Grant, Comput. Phys. Comm. 177, 597
(2007)
[2] V.A. Dzuba, V.V. Flambaum, J.S. Ginges, Phys. Rev. A 61, 062509 (2000)
CP 11
33
On the solution of the time dependent Dirac
equation for hydrogen-like systems
S. Selstø, J. Bengtsson, E. Lindroth
Atomic Physics, Fysikum, Stockholm University, AlbaNova University Center,
SE-106 91 Stockholm, Sweden
The time dependent Dirac equation for a hydrogen-like system exposed to a short, intense
electromagnetic pulse is solved numerically by expanding the wave function in eigenstates
of the unperturbed Hamiltonian. These eigenstates are obtained by diagonalizing the
Dirac Hamiltonian on an exponential grid. As the field parameters (field strength and
frequency) increases, both magnetic and relativistic effects become important. Furthermore,
for higher nuclear charges, relativistic effects are important even for relatively weak
fields. The need for a non-dipole and relativistic treatments is investigated by direct
comparison with the corresponding predictions of the Schr¨odinger equation in the dipole
approximation.
Although the fields considered are far below the threshold for pair-creation, negative
energy states may still play a role during the interaction. The possible influence of such
states is considered by propagating the wave function in field dressed states, which are
obtained by diagonalizing the full Hamiltonian. After each diagonalization the negative
energy states are removed from the basis.
In order to minimize the number of basis states needed, complex scaling has been applied.
CP 12
34
Calculation of parity-nonconserving amplitude in Ra+
Rupsi Pal1, Dansha Jiang1, Marianna Safronova1, and Ulyana Safronova2
1University of Delaware, Newark, Delaware, 19716 USA
2University of Nevada, Reno, Nevada, 89523, USA
E-mail: msafrono@udel.edu
Experimental measurements of the spin-dependent contribution to the PNC 6s ! 7s
transition in 133Cs led to a value of the cesium anapole moment that is accurate to about
14% [1]. The analysis of this experiment, which required a calculation of the nuclear spindependent
PNC amplitude, led to constraints on weak nucleon-nucleon coupling constants
that are inconsistent with constraints from deep inelastic scattering and other nuclear
experiments. New experiments (and associated theoretical analyses) are needed to resolve
the issue.
Comparing experimental weak charges of atoms QW, which depend on input from atomic
theory, with predictions from the standard model provide important constraints on possible
extensions of the standard model. Indeed, a recent analysis [2] of parity-violating
electron-nucleus scattering measurements combined with atomic PNC measurements placed
tight constraints on the weak neutral-current lepton-quark interactions at low energy, improving
the lower bound on the scale of relevant new physics to 1 TeV.
We have calculated parity-nonconserving 7s − 6d amplitude E1PNC in Ra+, using relativistic
high-precision all-order method where all single and double excitations of the
Dirac-Hartree-Fock wave function are included to all orders of perturbation theory. Detailed
study of the uncertainty of the PNC amplitude is carried out; additional calculations
are performed to evaluate the effect of the triple excitations and to estimate some of the
missing correlation corrections. A systematic study of the parity-conserving atomic properties,
including the calculation of the transition matrix elements, lifetimes, hyperfine
constants, as well as dipole and quadrupole ground state polarizabilities, is carried out.
The comparisons are made between the size of the correlation corrections in Ba+ and Ra+.
The results are compared with other theoretical calculations and available experimental
values.
References
[1] C. S. Wood, S. C. Bennett, D. Cho, B. P. Masterson, J. L. Roberts, C. E. Tanner, and
C. E. Wieman, Science 275, 1759 (1997).
[2] R. D. Young, R. D. Carlini, A. W. Thomas, and J. Roche, Phys. Rev. Lett. 99, 122003
(2007).
CP 13
35
Development of the CI + all-order method for
atomic calculations
Marianna Safronova1, M. G. Kozlov2, and W. R. Johnson3
1University of Delaware, Newark, Delaware, 19716 USA
2Petersburg Nuclear Physics Institute, Gatchina, 188300, Russia
3University of Notre Dame, Notre Dame, Indiana, 46556, USA
E-mail: msafrono@udel.edu
The development of the relativistic all-order method where all single and double excitations
of the Dirac-Hartree-Fock wave function are included to all orders of perturbation
theory led to accurate predictions for energies, transition amplitudes, hyperfine constants,
and other properties of monovalent atoms as well as the calculation of parity-violating
amplitudes in Cs and Fr [1]. The all-order method is designed to treat core-core and corevalence
correlations with high accuracy. Precision calculations for atoms with several
valence electrons require an accurate treatment of the very strong valence-valence correlation;
a perturbative approach leads to significant difficulties. In this work, we develop
a novel method for precision calculation of properties of atomic systems with more than
one valence electron. This method combines the all-order approach currently used in precision
calculations of properties of monovalent atoms with the configuration interaction
(CI) approach.
The precision of the CI method is generally drastically limited for large systems by the
number of the configurations that can be included. As a result, core excitations are
neglected or only a small number of them are included, leading to a significant loss of
accuracy for heavy atoms. In the CI + all-order approach, core excitations are incorporated
in the CI method by constructing an effective Hamiltonian using fully converged
all-order excitations coefficients. Therefore, the core-core and core-valence sectors of the
correlation corrections for systems with few valence electrons will be treated with the
same accuracy as in the all-order approach for the monovalent system. The CI method
will then be used to treat valence-valence correlations. This method is expected to yield
accurate wave functions for subsequent calculations of various atomic properties (such as
lifetimes, polarizabilities, hyperfine constants, parity-violating amplitudes, etc).
The preliminary results for Mg, Al, Sr, and Ba are presented.
References
[1] M.S. Safronova and W.R. Johnson, Advances in Atomic, Molecular, and Optical
Physics 55, 191 (2008).
CP 14
36
Ground state wavefunctions for two-electron systems
with ¯nite nuclear mass
K. V. Rodriguez1;4, V. Y. Gonzalez1;4, L. U. Ancarani2, D. M. Mitnik3;4
and G. Gasaneo1;4
1Departamento de F¶³sica - Universidad Nacional del Sur, 8000 Bah¶³a Blanca, Argentina
2Laboratoire de Physique Mol¶eculaire et des Collisions,
Universit¶e Paul Verlaine - Metz, France
3Instituto de Astronom¶³a y F¶³sica del Espacio, y Departamento de F¶³sica, Facultad de
Ciencias Exactas y Naturales, Universidad de Buenos Aires. C.C. 67, Suc. 28,
(C1428EGA) Buenos Aires, Argentina
4Consejo Nacional de Investigaciones Cient¶³¯cas y T¶ecnicas, Argentina
The basis functions proposed by Gasaneo and Ancarani in [1] are used to construct trial
wavefunctions for several two-electron systems. The focus here is on the study of the
following negatively charged hydrogenlike ions : 1H¡, 1H¡; D¡, T¡ and Mu¡, the negative
positronium ion Ps¡, and some exotic systems e¡e¡(nme)+ in which one of the particles
is heavier than the other two. All these systems are similar to each other in the main
property of their spectra, i.e. they have only one bound (ground), singlet state with
angular momentum L = 0. The basis functions satisfy exactly all the two-body Kato
cusp conditions. Following the methodology proposed in [2], each term of the basis is
multiplied by a series which does not a®ect this property. In terms of the interparticle
coordinates rij (i 6= j), the trial wave functions, with N the number of (linear) variational
parameters, are constructed as
ªC3¡N =
X
n1;n2;n3
'n1(¹13; r1)'n2(¹23; r2)ÂC3(n3; ¹12; r12)
X
ijk6=1
cn1n2n12
ijk ri
1 rj
2rk
12
where ¹ij are the reduced masses, 'ni are l = 0 hydrogenic functions of principal quantum
numbers ni, and ÂC3 = 1F1(¡n3; 2;¡2¹12r12=n3) with n3 a positive integer is the angular
correlation factor [1,3] which results from the analytic continuation of the widely used
double continuum three-body Coulomb (C3) wave function [4].
We also investigate systems of the form e¡e¡(nme)+ where (nme)+ refers to exotic par-
ticles with masses m3 equal n times the mass of the positron but with the charge of the
positron (+). Taking n from 1 to 1 we have obtained approximate analytical expressions
for the energies and some mean radial quantities, as functions of the mass of the heaviest
particle m3.
Results of the mean energy and other radial quantities will be shown at the conference
for the ions 1H¡, 1H¡; D¡, T¡, Mu¡ and the exotic systems e¡e¡(nme)+.
References
[1] G. Gasaneo and L.U. Ancarani, Phys. Rev. A 77, 012705 (2008)
[2] K.V. Rodriguez, G. Gasaneo and D.M. Mitnik, J. Phys. B 40 (19), 3923 (2007)
[3] L.U. Ancarani and G. Gasaneo, Phys. Rev. A 75, 032706 (2007)
[4] C.R. Garibotti and J.E. Miraglia, Phys. Rev. A 21, 572 (1980)
CP 15
37
Laser separation and detecting the isotopes and
nuclear reaction products and relativistic calculating
the hyper¯ne structure parameters in the
heavy-elements
O.Yu. Khetselius
Odessa University, P.O.Box 24a, Odessa-9, 65009, Ukraine
Relativistic calculation of the spectra hyper¯ne structure parameters for heavy elements
is carried out. Calculation scheme is based on gauge-invariant QED perturbation theory
with using the optimized one-quasiparticle representation at ¯rst in the theory of the hy-
per¯ne structure for relativistic atomic systems [1,2]. Within the new method it is carried
out calculating the energies and constants of the hyper¯ne structure for valent states of
cesium 133Cs, Cs-like ion Ba, isotopes of 201Hg, 223Ra, 252Cf are de¯ned. The con-
tribution due to inter electron correlations to the hyper¯ne structure constants is about
120-1200 MHz for di®erent states, contribution due to the ¯nite size of a nucleus and
radiative contribution is till 2 dozens MHz. Obtained data for hyper¯ne structure param-
eters are used in further in laser photoionization detecting the isotopes in a beam and the
bu®er gas for systematic studying the short-lived isotopes and nuclear isomers. We pro-
pose a new approach to construction of the optimal schemes of the laser photoionization
method for further applying to problem of the nuclear reactions products detecting. It's
studied the reaction of spontaneous 252Cf isotope ¯ssion on non-symmetric fragments,
one of that is the cesium nucleus. The corresponding experiment on detecting the reac-
tions products is as follows. The heavy fragment of the Cf nucleus ¯ssion created in the
ionized track 106 electrons which are collected on the collector during 2 mks. The collec-
tor is charged negatively 40mks later after nuclear decay and 10mks before the laser pulse
action. The photo electrons, arised due to the selective two-stepped photoionization are
drafted into the proportional counter for their detecting. Usually a resonant excitation of
Cs is realized by the dye laser pulse , the spectrum of which includes the wavelengths of
two transitions 6S1/2-7P3/2 (4555A) and 6S1/2-7P1/2 (4593A). This pulse also realizes
non-resonant photoionization of the Cs excited atoms. The disadvantages of the standard
scheme are connected with non-optimality of laser photoionization one, e®ects of impact
lines broadening due to the using the bu®er gas, the isotopic shift and hyper¯ne struc-
ture masking etc. We proposed new laser photoionization scheme, which is based on a
selective resonance excitation of the Cs atoms by laser radiation into states near ioniza-
tion boundary and further autoionization decay of excited states under action of external
electric ¯eld [2]. The corresponding optimal parameters of laser and electric ¯elds, atomic
transitions, states, decay parameters etc are presented.
References
[1] A. Glushkov, O. Khetselius et al, Nucl. Phys. A. 734, e21 (2004)
[2] A. Glushkov, O. Khetselius et al, Recent Adv. in Theory of Phys. and Chem. Syst.
(Springer). 15, 285 (2006)
CP 16
38
QED approach to the photon-plasmon transitions
and diagnostics of the space plasma turbulence
A.V. Glushkov12, O.Yu. Khetselius2, A.A. Svinarenko2
1Institute for Spectroscopy of Russian Academy of Sciences, Troitsk, 142090, Russia
2Odessa University, P.O.Box 24a, Odessa-9, 65009
Energy approach in QED theory [1-4] is developed and applied to modelling photon-
plasmon transitions with emission of photon and Langmuir quanta in space and astro-
physical plasma. It is well known that the positronium Ps is an exotic hydrogen isotope
with ground state binding energy of E = 6:8 eV. The hyper¯ne structure states of Ps
di®er in spin S, life time t and mode of annihilation. The ortho-Ps atom has a metastable
state 2s1 and probability of two-photon radiation transition from this state into 1s1 state
0:0018s¡1. In the space plasma there is the competition process of destruction of the
metastable level - the photon-plasmon transition 2s ¡ 1s with emission of photon and
Langmuir quanta. We carried out calculation of the probability of the photon-plasmon
transition in the Ps. The approach represents the decay probability as an imaginary part
of energy shift dE, which is de¯ned by S-scattering matrix. Standard S-matrix calcula-
tion with using an expression for tensor of dielectric permeability of the isotropic plasma
and dispersion relation- ships for transverse and Langmuir waves allows getting the cor-
responding probability P(ph ¡ pl). Numerical value of P(ph ¡ pl) is 5:2 ¢ 106U(1=s),
where U is density of the Langmuir waves energy. Our value is correlated with others:
P(ph¡pl) = 6¢106U(1=s). Comparison of obtained probability with lifetime t (3 gamma)
allows getting the condition of predominance of photon- plasmon transition over three-
photon annihilation. The considered transition may control the population of 2s level and
search of the long-lived Ps state can be used for diagnostics of the plasma turbulence.
References
[1] A. Glushkov, L.N. Ivanov, Phys. Lett.A. 170, 33 (1992); Preprint ISAN N AS-4,
Moscow-Troitsk (1994)
[2] A. Glushkov, et al, J. Phys. CS. 11, 188 (2004)
[3] A. Glushkov, et al, Int. Journ. Quant. Chem. 99, 936 (2004)
[4] A. Glushkov, Low Energy Antiproton Phys. 796, 206 (2006)
CP 17
39
QED theory of laser-atom and laser-nucleus
interaction
A.V. Glushkov12
1Institute for Spectroscopy of Russian Academy of Sciences, Troitsk, 142090, Russia
2Odessa University, P.O.Box 24a, Odessa-9, 65009
QED theory is developed for studying interaction of atoms and nuclei with an intense
and superintense laser ¯eld. Method bases on a description of system in the ¯eld by the
k- photon emission and absorption lines. The lines are described by their QED moments
of di®erent orders, which are calculated within Gell-Mann Low adiabatic formalism [1-
4]. The analogous S-matrix approach is developed for consistent description of the laser-
nucleus interaction. We have studied the cases of single-, multi-mode, coherent, stochastic
laser pulse shape. An account for stochastic °uctuations in a ¯eld e®ect is of a great im-
portance. Results of the calculation for the multi-photon resonance and ionization pro¯le
in Na,Cs, Yb, Gd atoms are presented. It is also studied the phenomenon of the above
threshold ionization. E±ciency of method is demonstrated by QED perturbation theory
calculations for the two-photon ionization cross-sections for extended photon energy range
(including above-threshold ionization) in Mg. Comparison with the R-matrix calculation
of Luc-Koenig et al [3] is given. There is considered a phenomenon of the Rydberg stabi-
lization of the H atom in a strong laser ¯eld and estimated the rate of transition between
the stabilized Rydberg state (n=40,m=2; E 10(8)V/cm ) and ground state, when it's
possible the radiation of photons with very high energy (short-wave laser ampli¯cation).
DC strong ¯led Stark e®ect for atoms, including atoms in plasma, Rydberg atoms and
con¯ned systems is studied within new quantum approach, based on the operator PT [1].
The zeroth order Hamiltonian, possessing only stationary states, is determined only by its
spectrum without specifying its explicit form. We present here the calculation results of
the Stark resonances energies and widths for a number of atoms (H, Li, Tm,U etc.) and
for a whole number of low-lying and also Rydberg states. We discovered and analyzed
the weak ¯eld e®ect of drastic broadening of widths of the Letokhov-Ivanov re-orientation
decay autoionization resonances in Tm etc. Developed approach can be naturally applied
to studying the Stark e®ect in con¯ned systems, including quantum wells, quantum dots
etc, where especially interesting e®ects may occur.
References
[1] A. Glushkov, L.N. Ivanov, Phys. Lett.A. 170, 33 (1992); Preprint ISAN N AS-2,
Moscow-Troitsk (1992)
[2] A. Glushkov, et al, J. Phys. CS. 11, 188 (2004)
[3] A. Glushkov, et al, Int. Journ. Quant. Chem. 99, 936 (2004); 99, 889 (2004); 104,
512 (2005); 99, 562 (2005);
[4] A. Glushkov, Low Energy Antiproton Phys. 796, 206 (2006)
CP 18
40
Quantum dynamics of planar hydrogen atom in a
billiard with moving boundaries
Kh.Yu. Rakhimov
Heat Physics Department of the Uzbek Academy of Sciences,
28 Katartal St., Tashkent 100135, Uzbekistan
kh rakhimov@yahoo.com
Particle motion in con¯ned geometries is an important problem providing to explore
many features of classical nonlinear dynamics and quantum dynamics of classically non-
integrable systems. Due to recent progress in the physics of mesoscopic systems and
nanophysics this problem has become attractive from the practical viewpoint, too. Such
systems as quantum dots, trapped atoms, nanotubes are the realistic systems where con-
¯ned electron dynamics play important role. Usually in studying these systems the bound-
aries of con¯nement are considered as strictly ¯xed. However, in many practically impor-
tant situations the con¯nement boundaries are not strictly ¯xed and °uctuate in space,
oscillate or move in one direction.
In present work we study quantum dynamics of an electron in the Coulomb ¯eld whose
motion is con¯ned by time-dependent billiard boundaries. Exploring of billiards with
moving walls require solution of the two-dimensional SchrÄodinger equation with time-
dependent boundary conditions. Here we solve the SchrÄodinger equation for Coulomb
potential with the boundary conditions given on circle with time-dependent radius. It
well known that in most of the realistic situations with atoms con¯ned in various traps
the trap boundaries are not ¯xed but time-dependent. Solving the problem numerically
we obtain time-dependence of the electron energy and compute density of states. The
results obtained show that in the case of oscillating boundaries the energy of electron
grows in time. However, this growth is strongly suppressed upon reaching certain value.
This value depends on the frequency and amplitude of the billiard wall oscillations.
CP 19
41
Interchannel interaction in orientation and alignment
of Kr 4p4mp states in the excitation region
of 3d9np resonances
B.M. Lagutin1, I. D. Petrov1, V. L. Sukhorukov1, A. Ehresmann2, L.Werner2,
S. Klumpp2, K.-H. Schartner3 and H. Schmoranzer4
1Rostov State University of Transport Communications, 344038 Rostov-on-Don, Russia,
2Institut fÄur Physik, UniversitÄat Kassel, 34109 Kassel, Germany,
3I. Physikalisches Institut, Justus-Liebig-UniversitÄat, D-35392 Giessen, Germany,
4Fachbereich Physik, Technische UniversitÄat Kaiserslautern,
D-67653 Kaiserslautern, Germany
E-mail: schmoran@rhrk.uni-kl.de
In combined theoretical and experimental e®orts we studied the interchannel interaction
in°uencing the population of Kr 4p4mp ionic states in the excitation energy region around
the 3d9np resonances by photon-induced Auger decay. This resonant Auger process was
shown to be treated as an interference of strong resonant and weak direct nonresonant
ionization channels [1]. This interference leads to the energy dependence of the orientation,
O10, and the alignment, A20, of the ¯nal ionic states and also of the angular distribution
of outgoing electrons and °uorescence photons. The above quantities are rather sensitive
to the interference mechanism, especially when studied in the wings of the resonances [2].
In the present work the theoretical treatment of the non-resonant pathway was extended
with respect to the monopole shake-process considered earlier. The non-monopole pro-
cesses including both intra- and intershell correlations were taken into account. The
main non-monopole contributions to the direct transition amplitude stem from the 4p5"0`
(` = s; d) and 3d9"0` (` = p; f) intermediate states.
Correlation e®ects modify the partial monopole shake-amplitudes for the outgoing waves
"` di®erently and this e®ect changes the energy dependence of the O10 and A20 parame-
ters. The calculated data agree closely with the measured orientation parameter for the
4p4(1D)5p 2P3=2 ¯nal ionic state in the extended energy region between the 3d9
5=25p3=2
and 3d9
5=26p3=2 resonances. This result asks for new extended experimental data on the
angular distribution parameters for other ¯nal ionic states, too.
The quality of the wavefunctions used in the calculation was checked by comparing the
computed and recently measured [3] photoionization cross sections for di®erent 4p4(L0S0)mp
satellites in the region of the 3d9np resonances. Good agreement between theory and ex-
periment was observed in all cases. The photoelectron angular distribution measured and
computed in [3] for the above satellites is also compared with the present calculations.
References
[1] Lagutin B.M. et al., Phys.Rev.Lett. 90, 073001 (2003)
[2] Schartner K.-H. et al., J.Phys.B 40, 1443 (2007)
[3] Sankari A. et al., Phys.Rev.A 76, 022702 (2007)
CP 20
42
Application of new quasirelativistic approach for
treatment of oxygen-like Iron and Nickel
O. Rancova, P. Bogdanovich and R. Karpu skien_e
Institute of Theoretical Physics and Astronomy of Vilnius University
A. Go stauto st. 12, 01108 Vilnius, Lithuania
E-mail: olga@itpa.lt
An urgent demand for high precision calculations of atomic characteristics of heavy atoms
and highly charged ions with complex electron con gurations encourages the development
of new methods and computer codes. Possibilities of the new quasirelativistic approach
designed for ab initio calculations of spectral characteristics of highly charged ions and
heavy atoms are investigated and illustrated with an example of a study of spectral
characteristics of oxygen-like ions of Iron and Nickel. Within the quasirelativistic approach
the main relativistic e ects are taken already into account when obtaining the radial
orbitals. The main distinctions between the approach under investigation and the well-
known computer code by R. D. Cowan based on the methods described in [1] are the
following: the quasirelativistic equations for the radial orbitals are newly formed in a
di erent shape [2,3], the nite size of the atomic nucleus is taken into account while
solving the equations [4], the de nition of the radial integrals of the energy operator is
re ned, the transformed radial orbitals are created for the description of virtual excitations
while performing the con guration interaction.
The calculations executed within the described approach were reduplicated by the ana-
logical calculations based on the usual non-relativistic radial orbitals. It allows one to
evaluate the advantages and the new possibilities appearing while using the quasirela-
tivistic radial orbitals against the conventional non-relativistic radial orbitals when the
correlation e ects are taken into account in the same way performing the con guration
interaction on the basis of transformed radial orbitals.
The energy spectra, transition characteristics and lifetimes of Fe XIX and Ni XXI ions
calculated by two mentioned methods are calculated. The obtained results are compared
with the experimental data and with the theoretical calculations of other authors. From
the comparison it is obvious that the quasirelativistic approach enables us to obtain the
data of high precision and that the structure of the energy spectra calculated perfectly
coincides with the experimental spectra.
Acknowledgments
This work, partially supported by the European Communities under the contract of As-
sociation between EURATOM/LEI FU06-2006-00443, was carried out within the frame-
work of the European Fusion Development Agreement. The views and opinions expressed
herein do not necessarily re ect those of the European Commission.
References
[1] R. D. Cowan, The theory of atomic structure and spectra, (University of California
Press, Berkeley, 1981)
[2] P. Bogdanovich, O. Rancova, Phys. Rev. A 74, 052501 (2006)
[3] P. Bogdanovich, O. Rancova, Phys. Rev. A 76, 012507 (2007)
[4] P. Bogdanovich, O. Rancova, Lithuanian. J. Phys. 42, 257 (2002)
CP 21
43
Relativistic recoil and higher-order electron
correlation corrections to the transition energies in
Li-like ions
Y. S. Kozhedub1, D. A. Glazov1, I. I. Tupitsyn1, V. M. Shabaev1, and G. Plunien2
1 Department of Physics, St. Petersburg State University, Oulianovskaya 1,
Petrodvorets, St. Petersburg 198504, Russia
2 Institut fur Theoretische Physik, TU Dresden, Mommsenstra e 13, D-01062 Dresden,
Germany
E-mail: kozhedub@pcqnt1.phys.spbu.ru
Traditionally, investigations of isotope shift in atomic spectra have been carried out mainly
to determine the di erence in the root-mean-square nuclear radii hr2i. Recently new
applications emphasized the relevance of this e ect. For instance, isotope shift calculations
in atoms and ions can be important for astrophysical search for possible -variation,
where the isotope shift induces valuable systematic error. Moreover, investigations of this
e ect could provide information about isotopic abundances in the early Universe, which
is tightly linked with the general evolution of the Universe. The study of isotope shifts in
highly charged ions has the potential advantage of an increased sensitivity to nuclear size
and relativistic e ects due to the stronger overlap of the electronic wave function with
the nuclear matter and of the simpler electronic structure of few-electron ions as opposed
to their neutral atomic counterparts.
Nuclear recoil e ect is the most di cult part of isotope shift to evaluate. In the present
paper, we perform accurate calculations of the nuclear recoil e ect for ions along the
lithium isoelectronic sequence. The full relativistic theory of the nuclear recoil e ect
can be formulated only in the framework of QED [1]. In order to evaluate the recoil
e ect within the lowest-order relativistic approximation one can use the relativistic recoil
operator. Within this approximation the recoil correction is calculated with many-electron
wave functions in order to take into account the electron-correlation e ect. The one- and
two-electron contributions to the recoil e ect are evaluated to all orders in Z. Comparing
the isotope shifts calculated with recent experimental data indicates very good prospect
for test of the relativistic theory of the recoil e ect in middle-Z ions.
We present also the most accurate up-to-date theoretical values of the 2p1=2-2s and 2p3=2-
2s transition energies in middle-Z Li-like ions. All presently available contributions to
the transition energies are collected. Except for the one-electron two-loop corrections, all
other terms up to the two-photon level are treated within the framework of bound-state
QED to all orders in Z. The interelectronic interaction beyond the two-photon level
is evaluated within the Breit approximation by means of the large-scale con guration-
interaction Dirac-Fock-Sturm method. We report accurate numerical values of the higher-
order interelectronic-interaction correction for Li-like ions up to uranium. The results
obtained for the transition energies are in good agreement with recently published exper-
imental data. In the case of lithiumlike scandium, they were reported in Ref. [2].
References
[1] V. M. Shabaev, Phys. Rev. A 57, 59 (1998); Phys. Rep. 356, 119 (2002).
[2] Y. S. Kozhedub et al., Phys. Rev. A 76, 012511 (2007).
CP 22
44
Coupled tensorial forms of atomic two-particle
operator
R. Jurˇs˙enas
Institute of Theoretical Physics and Astronomy of Vilnius University, A. Goˇstauto 12,
LT-01108 Vilnius, Lithuania
For many-electron atoms and ions the ability to present a two-electron operator and its
matrix elements in an optimal form may be decisive for successful calculation solutions
of many theoretical spectroscopy problems. Here a two-particle operator is expressed in
second quantization representation (SQR). Special attention is paid to the approach when
the expressions for the operator considered are given in terms of submatrix elements of the
coupled two-electron wave function [1]. This gives more freedom in choosing a convenient
way for the calculations of matrix elements for open-shell atoms.
In a SQR two approaches were considered to express an arbitrary two-electron operator
in a coupled tensorial form for multi-shell atoms. The expressions of both topologically
different approaches are applicable to the study of the operators representing atomic interactions
as well as the operators describing some effective interactions appearing, for
instance, in an atomic many body perturbation theory (MBPT) or a coupled cluster
method.
The first approach is more suitable when one seeks effectively to calculate the matrix
elements of (one) particular operator because the internal ranks of operator are involved
in the calculation of many-electron angular part. The second approach is superior for
the problems where several operators with different tensorial structure are considered, for
example, the formation of energy matrix of atomic Hamiltonian in Breit-Pauli approximation.
In this case, only the resulting ranks of operators enter in the expressions for the
submatrix elements of many-electron angular part and the computer codes used for such
calculations could be more efficient if they are based on the second approach.
The final result of the study is a large set of a two-particle operators acting in the space
of the states of one-, two-, three- and four-shells. The expressions can be used for both
nonrelativistic (LS coupling) and relativistic (jj coupling) approximations.
References
[1]. R. Jurˇs˙enas, G. Merkelis, Lithuanian Journal of Physics, Vol.47, No.3, 255-266 (2007).
CP 23
45
The binominal potential of electron-proton interaction
alternative to the Coulomb law
V.K. Gudym1 and E.V. Andreeva2
1Space National Agency of Ukraine, Kyiv, Ukraine
2Institute of Physics of Semiconductors of the NASU, Kyiv, Ukraine
E-mail:vgudym@mail.ru
On the basis of only classical assumptions, we have shown earlier [1, 2, 3] that an electron
and a proton interact by the binomial law
V = 􀀀
e2
r
+
􀀀
r2 (1)
and have determined the value of the constant 􀀀 as 6:10276 10􀀀28 CGSE units.
Potential (1) has been veri ed by us in the analysis of both the Kepler task of a hydrogen
atom where the energy takes the form
E = mr_2
2
+ M2
2mr2
􀀀
e2
r
+
􀀀
r2 (2)
and the Schrodinger equation
+
2m
h2

E + e2
r
􀀀
􀀀
r2
!
= 0 : (3)
We have also analyzed the scattering of an electron by a proton, as a special case of the
Kepler task. Below, we give the formula for the de ection angle '0b as a function of the impact
parameter :
'0b =
s
E 2
E 2 + 􀀀
arccos
2
4

1 +
4E(E 2 + 􀀀)
e4
!􀀀1=2
3
5 : (4)
The calculations have shown that the formula describing the scattering of electrons in the binomial
potential well represents the process within the range of impact parameters down to
10􀀀13cm for the energies of an electron from several eV up to hundreds of MeV . Further, on
the basis of potential (1), we have shown the basic opportunity for the solution of the classical
task concerning the movement of an electron in the eld of a proton for a hydrogen atom. On
this way, we were succesful to clarify the nature of the Bohr postulates, the Planck constant,
and some other constants which were not treated earlier within the framework of classical mechanics.
For the theory of Schrodinger, we have demonstrated, with the use of potential (1), the
opportunity to understand and to resolve a number of its internal contradictions. In particular,
it turns out to be possible to derive, for the rst time, a wave package being stable in time in
the problem concerning a hydrogen atom and to explain the mechanism of birth of a quantum
in the classical interpretation.
Generally, potential (1) can be considered as a link between the classical and quantum
theories.
References
[1] Gudym V.K. 2001, Visnyk Kyiv. Univ., N. 3, P. 254.
[2] Gudym V.K., Andreeva E.V. 2003, Poverkhn., N. 5, P. 59-63.
[3] Gudym V.K., Andreeva E.V. 2006, Poverkhn., N. 3, P. 113-117.
CP 24
46
The dynamics of meta-stable states described with a
complex scaled Hamiltonian
J. Bengtsson, E. Lindroth, and S. Selst
Atomic Physics, Fysikum, Stockholm University, S-106 91 Stockholm, Sweden
The laser development has given access to light pulses in the femto- and subfemtosecond
regime and thereby opened the possibility to follow electron dynamics directly in the time
domain. Of special interest is the dynamics of resonant states, and pioneering experi-
mental studies were made a few years ago on the Auger decay of inner-shell vacancies [1].
One widely spread theoretical technique, that successfully describes resonant states, is
that of complex scaling. With this method, the meta-stable states are obtained as unique
eigenstates to the eld-free complex scaled Hamiltonian. The half-width and the energy
position of the meta-stable state is furthermore given directly from the imaginary and the
real part of the corresponding eigenvalue respectively. Compared to many other methods,
such as the stabilization method where the manifestation of a resonant state is seen as a
local accumulations of pseudo-continuum states, this property is highly attractive from a
numerical point of view. A second appealing property, due to complex scaling, is that the
continuum is adequately represented by a very modest number of eigenstates. A similar
accuracy cannot be achieved using a conventional pseudo continuum. Due to the reasons
mentioned above, the method of complex scaling is also interesting for truly dynamical
systems, for instance atoms exposed to short light pulses followed by the possible popu-
lation of a meta-stable state. However, the complex scaled Hamiltonian is non-Hermitian
and the extension to dynamical calculations is not straight forward. Here we therefore
address the question of to what extent this technique might be applied to solve the time-
dependent Schrodinger equation and to what extent resonant states contribute to the
overall dynamical behaviour of the system. We have tested our approach against conven-
tional methods for the case of hydrogen.
References
[1] 1. M. Drescher et al. Nauture, 419, 807 (2002)
CP 25
47
A simple parameter-free wavefunction
for the ground state of three-body systems
L.U. Ancarani1 and G. Gasaneo2
1Laboratoire de Physique Mol¶eculaire et des Collisions,
Universit¶e Paul Verlaine - Metz, 57078 Metz, France
2Departamento de F¶³sica, Universidad Nacional del Sur and Consejo Nacional de
Investigaciones Cient¶³¯cas y T¶ecnicas, 8000 Bah¶³a Blanca, Buenos Aires, Argentina
The study of the structure and stability of Coulombic three-body systems [m1m2m3],
with arbitrary masses mi and charges zi (i = 1; 2; 3), has been the subject of many
investigations (see, e.g., the review [1]. Recently, we have proposed a pedagogical, simple
and parameter-free wavefunction for the ground state of two-electron atoms [2]. The
proposal was then generalized [3] to more general atomic three-body systems in which
one of the particles is positively charged (z3 > 0) and heavier than the other two which
are negatively charged (z1 < 0; z2 < 0).
Let ºij = ¹ijzizj where ¹ij = mimj
mi+mj
(i 6= j = 1; 2; 3) are the reduced masses. In terms of
the interparticles coordinates r1 = r13; r2 = r23 and r12 (particle 3 is placed at the origin
of the coordinates), the proposed wavefunction reads
ªGEN
ARG = NGEN
ARG eº13r1+º23r2 (1 + º12r12)
h
1 + c(r2
1 + r2
2)
i
;
where NGEN
ARG is the normalization constant and c is replaced by an analytical expression
in terms of (mi; zi) in order to minimize the mean energy of the ground state.
The wavefunction ªGEN
ARG : (i) has the same form for all systems; (ii) is parameter{free;
(iii) is nodeless; (iv) satis¯es, by construction, all two-particle cusp conditions [4]; and (v)
yields reasonable ground state energies for several systems including the prediction of a
bound state for H¡, D¡, T¡ and Mu¡. A wavefunction with all these characteristics is
presently not available in the literature. The simplicity of ªGEN
ARG is such that analytical
expressions for the ground state energy can be derived. Hence, we have a useful predictive
and simple analytical tool (which, to our knowledge, is not available in the literature) to
estimate the energy, and therefore to study the stability, of exotic Coulombic three{
body systems. In addition, our proposal is simple enough, but su±ciently accurate to be
used as a starting point in calculations of collision cross sections. Of course due to its
simplicity, energy values cannot compete with those obtained with advanced variational
wavefunctions which involve large number of basis functions. However, the latter (i) do
not have a predictive character since they have to be optimized each time for a given
three{body system.; (ii) in most cases, do not satisfy exactly Kato cusp conditions.
For illustration, results will be shown for the several three-body systems.
References
[1] E. A. G. Armour, J.-M. Richard and K. Varga, Phys. Rep. 413, 1 (2005).
[2] L. U. Ancarani, K. V. Rodriguez and G. Gasaneo, J. Phys. B 40, 2695 (2007).
[3] L. U. Ancarani and G. Gasaneo, J. Phys. B 41, in press (2008).
[4] T. Kato, Comm. Pure Appl. Math. 10 151 (1957).
CP 26
48
(e; 3e) and (°; 2e) processes on helium:
interplay of initial and ¯nal states
L.U. Ancarani1, G. Gasaneo2, F.D. Colavecchia3 and C. Dal Cappello1
1Laboratoire de Physique Mol¶eculaire et des Collisions,
Universit¶e Paul Verlaine - Metz, 57078 Metz, France
2Departamento de F¶³sica, Universidad Nacional del Sur and CONICET,
8000 Bah¶³a Blanca, Buenos Aires, Argentina
3Centro At¶omico Bariloche and CONICET,
8400 S. C. de Bariloche, R¶³o Negro, Argentina
Information on correlations can be gained from the theoretical study of the double ioniza-
tion of helium by electron impact ((e; 3e) experiments) [1]. Approximate wave functions
are always used in cross section calculations since no exact wave function is known for
either the scattering or the bound states. The resulting (e; 3e) cross sections obtained
with di®erent theoretical description of the initial and ¯nal states are not in agreement
with each other. Moreover, when these are compared with absolute experimental data, a
rather confusing picture emerges; this is the subject of many recent studies (as discussed
and summarized in [2]). It has been mentioned throughout the literature (see, e.g., [3])
that a balanced description of the initial and ¯nal two-electron states may play a key role
in reproducing experimental (e; 3e) data. This issue is investigated here with a systematic
study of double ionization cross sections of helium, by both electron and photon impact.
For (e; 3e) processes, calculated di®erential cross sections can be compared with the high
energy absolute experimental data [4]. The two electrons ejected in the ¯nal channel
at equal energy (10 eV) are modeled here with the "pure" C3 (or BBK) wave function
[5]. For the initial channel we consider di®erent sets of double bound wave functions with
only angular correlation or with both angular and radial correlation. The comparison with
the measurements allows us to see which of them are balanced when describing (e; 3e)
processes. Moreover, the photon impact (°; 2e) cross sections calculated in di®erent gauges
and with the same set of initial and ¯nal channel wave functions, indicate whether the
wave functions are really "balanced" or not.
Our study of the (°; 2e) gauge discrepancies shows that the agreement with absolute
(e; 3e) experimental data at 10+10 eV ejected energy obtained with simple initial states
is fortuitous and can hardly be attributed to a balanced description with respect to the
¯nal state. This result is further con¯rmed by an investigation of the ejected energy
dependence. Moreover, it seems that the approximate C3 wave function is not suitable
to describe su±ciently well the double continuum of two electrons ejected at 10 eV.
References
[1] J. Berakdar, A. Lahmam-Bennani and C. Dal Cappello Phys. Rep. 374, 91 (2003)
[2] L.U. Ancarani, G. Gasaneo, F.D. Colavecchia and C. Dal Cappello, submitted (2008)
[3] J. H. Macek and S. Jones, Rad. Phys. and Chem. 75, 2206 (2006)
[4] A. Lahmam-Bennani et al., Phys. Rev. A 59, 3548 (1999)
[5] C. R. Garibotti and J. E. Miraglia, Phys. Rev. A 21, 572 (1980); M. Brauner, J.
Briggs and H. Klar, J. Phys. B 22, 2265 (1989)
CP 27
49
A three body approach to calculate the differential cross
sections for the excitation of H and He atoms by proton impact
R. Fathi2, E. Ghanbari-Adivi3, F. Shojaei Baghini1, and M.A. Bolorizadeh1
1Physics Department, Shahid Bahonar University of Kerman, Kerman, Iran
2Physics Department, Islamic Azad University, Kerman Branch, Kerman, Iran
3Physics Department, Isfahan University, Isfahan, Iran.
mabolori@mail.uk.ac.ir
A method based on the three-body formalism incorporated into the Born series have been developed to
calculate the excitation of hydrogen and helium atom by proton impact at medium and high energies. The
Faddeev type approaches to the scattering of charged particles are a rearrangement of Born series. However,
the on shell transition matrix is not well defined by any method based on the Lippmann-Schwinger
integral equation. We have developed a method incorporating the FWL formalism in conjunction with
Born approximation to calculate the differential cross section for the excitation of hydrogen and helium
atom by protons of energy 50 keV to 500 keV. In the case of hydrogen atom, excitation to the final states
2s, 2p and 3s were included while for the case of atomic helium the calculations were performed for the
final states 21S and 23S.
The excitation of atomic hydrogen is a three body process. However, the excitation of helium is simplified
by an active model where the second electron is assumed frozen. The wave function for the final state
of helium is chosen from literature[1]. We have also deduced a simple method using a Slater type wave
function as:
Ã(r) = 0.854(1 − 1.15r/2) exp(−1.15r) + 0.488 exp(−1.6875r). (1)
The differential cross sections
for the excitation of helium
and hydrogen atoms are plotted
in figures 1(a) and 1(b),
respectively. In the case of
helium atom, the calculations
were performed using two different
wave functions for the
final state of the helium atom,
21S. One was the CHF wave
functions [1] and the other
one was the wave function
of equation 1. Figure 1(b)
shows the calculations for the
final state 2s and 2p of hydrogen.
The results are compared
with the experimental
work of Park and his coworkers
[2,3].
0.0 0.2 0.4 0.6 0.8
10 3
10 4
10 5
10 6
10 7
X 0.25
(a)
Differential Cross Section for Excitation (a.u) CM Scattering Angle(mrad)
Exp. Results by Park [2]
Present Work (CHF
wave function)
Present Work
(A Simple Model)
0.0 0.2 0.4 0.6 0.8 1.0
10 4
10 5
10 6
10 7
10 8
(b) Exp. Results by Park [3]
Present Work
CM Scattering Angle (mrad)
Figure 1. The excitation cross section for (a) helium and (b) hydrogen
atom by proton impact at 50keV. The experimental results
are from Park and co-workers.
Acknowledgement:
The authors would like to thank Dr. M. Shojaei for his help in the preparation of the manuscript.
References
[1] G. N. Bhattacharya and G. S. Kastha, J. Phys. B: At. Mol. Phys. 14, (1981), 3007
[2] T.J. Kvale, et al, Phys. Rev. A 32 (1985) 1369
[3] J.T. Park, et al, Phys. Rev. A 21 (1980) 751
CP 28
50
CP 29
51
CP 30
52
CP 31
53
Ionization and Dissociative Ionization of Adenine
Molecules by Electron Impact near Threshold
O.B.Shpenik, A.N.Zavilopulo
Institute of Electron Physics, Ukr. Nat. Acad. Sci.
21 Universitetska str., Uzhgorod 88017, Ukraine
E-mail: an@zvl.iep.uzhgorod.ua
An increased interest to the studies of biomolecules by traditional methods of physics of
electron collisions is explained by the significance of these molecules in modern life. Here
we report on a study of the features of the process of ionization, including dissociative
ionization, of adenine molecules under electron impact, accompanied by the formation of
ionized products of reaction. The experimental setup, used for the investigation of partial
cross-sections of dissociative ionization of molecules by electron impact, is described in
detail in a number of our papers (See, e. g., [1]). The setup is constructed on the base
of a monopole mass spectrometer with an electron ionizer and a multichannel molecule
source of effusion type. The ionic products of dissociative ionization, separated by the
high-frequency field of the analyser, were detected by a channeltron. The scanning of
the ionizing electron energy and data acquisition were performed using a computer and
a specially developed software. The duration of one measurement cycle was chosen in
such a way that the number of pulses of the useful signal in the maximum of the energy
dependence curve should not be less than 104. In short, the measurement technique
was the following. At first the adenine molecule mass spectrum was measured at the
ionizing electron energy of 40 and 70 eV , then for each fragment the dissociative ionization
function was measured. The mass scale was calibrated using Ar, Kr and Xe, and a special
procedure of polynomial fitting of the threshold part of the ionization cross-section [2] was
used to determine the appearance potentials of various ion fragment groups. The fragment
appearance potentials were determined from the threshold dependences of the ion yield.
We also studied temperature dependences of intensities of the ion fragments of the initial
molecule in the temperature range 343−480 K. The measurement technique was reduced
to the measurement of mass spectra at various temperatures at Eion = 50 eV . From the
temperature dependences, the evolution of the fragment formation could be traced and the
effect of temperature on the dissociative ionization could be observed. We have measured
energy dependences of the total cross-section of the adenine molecule ionization as well as
the cross-sections of dissociative ionization of formation of the fragment ions. We have also
determined the appearance potentials for the fragment ions with m/e = 43, 54, 81, 108.
This work was supported in part by the CRDF Grant ]UKC − 2832 − UZ − 06.
References
[1] A.N. Zavilopulo, O.B. Shpenik, V.A. Surkov, Anal.Chim.Acta 573-74, 427-431 (2006).
[2] T. Fiegele, at.al, J.Phys.B: Atom. Mol. Opt. Phys. 33, 4263-4269 (2000).
CP 32
54
CP 33
55
Charge transfer in collision of protons with water molecule
and atomic helium at high energy
S. Houamer1, Y. Popov2 , C. Champion3 and C. Dal Cappello3
1 Laboratoire de Physique Quantique et Systèmes dynamiques, Département de physique,
Faculté des sciences, Université Ferhat Abbas, Sétif, 19000 , Algeria
2Nuclear Physics Institute, Moscow state University, Moscow 119899, Russia
3Laboratoire de Physique Moléculaire et des Collisions, Institut de Physique, 1 Boulevard
Arago, 57078 Metz Cedex 3, France
Charge transfer process in collision of protons with water molecule and helium is
investigated at high energy using a first Born model in which different reaction mechanisms
are considered. A sophisticated configuration interaction wave function is used to describe
helium atom while the projectile is described by a plane wave.
The process is investigated for H20 molecule in the frozen core model where the target is
described by a single center wave function successfully used formerly in ionization
process. The SDCS is calculated for both targets at high impact energy . The
TCS is than deduced by direct integration over solid angle in an energy range between 0.1
and 3 MeV. The results are finally compared with experiments in order to check the
validity of the model.
E MeV i = 1.4
0 ,1 1 1 0
1 E - 2 3
1 E - 2 2
1 E - 2 1
1 E - 2 0
1 E - 1 9
1 E - 1 8
1 E - 1 7
1 E - 1 6
1 E - 1 5
1 E - 1 4
1 E - 1 3
1 E - 1 2
0 ,1 1 1 0
1 E - 2 7
1 E - 2 6
1 E - 2 5
1 E - 2 4
1 E - 2 3
1 E - 2 2
1 E - 2 1
1 E - 2 0
1 E - 1 9
1 E - 1 8
1 E - 1 7
1 E - 1 6
1 E - 1 5
H 2 O
TCS (cm
2
)
P r o to n e n e r g y (M e V )
H e
Fig. 1 Absolute TCS for electron capture in proton collision with H2O and He.
Experimental data are taken from [1] for H2O and [2] for He.
It should be noted that for a water molecule three more integrations must be performed to
average over the random orientation of the molecular target.
[1] J. H. Toburen, M. Y. Nakal and R. A. Langley, Phys. Rev. 171, 114 (1968)
[2] I. Mancev, V. Mergel and L. Schmidt, J. Phys. B 36 2733 (2003)
CP 34
56
Ar(3p54p) states excitation in low-energy
Ar-Ar collisions
S.Yu. Kurskov and A. S. Kashuba
Department of Physics and Engineering, Petrozavodsk State University
Lenin 33, 185910 Petrozavodsk, Russia
E-mail: kurskov@psu.karelia.ru
The present work is devoted to study of Ar(3p5 4p) states excitation in binary low-energy
Ar{Ar collisions. The purpose of this work is the research of mechanisms of atomic levels
excitation at collision energies that corresponds of the adiabatic approximation conditions.
The results of the experimental investigation of excitation cross sections of Ar I 4p0[1/2]1,
4p0[3/2]1, 4p0[3/2]2 and 4p[3/2]2 levels in the collision energy range from threshold up to
500 eV (centre of mass system) and degree of polarization for 4s[3/2]0
2 ¡ 4p0[1/2]1 and
4s[3/2]0
2 ¡ 4p[3/2]2 transitions in this energy range are represented.
The measurements of the cross sections at interaction of an atomic beam with a gas target
were carried out by optical methods on setup, controlled by computer. The measurement
procedure was described in detail in the work [1].
The obtained results demonstrate that the polarization degree of emission signi¯cantly
depends on collision energy { when the latter goes up, the former changes its sign. The fact
that the sign of the polarization degree changes, as well as does interaction energy, proves
that the mechanism of level population changes too [2]. For instance, since the angular
momentum of 4p0[1/2]1 excitation level is equal to 1, the positive polarization degree
shows that the magnetic sublevel ¾0, that is zero momentum projection onto internuclear
axis of the Ar2 quasimolecule, is mostly populated. Negative polarization degree, in its
turn, means that there is a dense population at magnetic sublevels ¾1, corresponding to
§1 projections. Therefore, according to the data obtained, if collision energy is higher
than 400 eV, the population at the mentioned above level is determined by §g ¡ §0
g
transactions. If collision energy is equal to or lower than 300 eV, level population is guided
by §g¡¦g transactions due to radial coupling of even terms of the Ar2 quasimolecule. It is
important to note that since output §g terms of the Ar2 quasimolecule are actually double
excited terms, supposedly, the other interacting atom is excited too. This fact agrees with
Wigner's law (system spin unchanged at collision) and with the research results described
in works [3, 4]. The diabatic molecular orbital diagram for homonuclear system [5] and
measurement results of the polarization of emission lead to the following conclusion: if
collision energy is less or equal to 300 eV, the population of 4p0[1/2]1 level is determined
by 4p¾ ¡ 4p¼ transactions due to rotational coupling at small nuclear distances. In case
of higher energies, the population is governed by 5f¾ ¡ 5d¾ transactions due to non-
adiabatic radial coupling.
Reference
[1] S.Yu. Kurskov, A.D. Khakhaev, Czech. J. Phys. 56, B297 (2006).
[2] K. Blum, Density Matrix Theory and Applications (N.Y., Plenum Press, 1981).
[3] P.J. Martin, G. Riecke, J. Hermann et al., J. Phys. B11, 1991 (1978).
[4] L. Moorman, V. van Hoegaerden, J. van Eck et al., J. Phys. B20, 6267 (1987).
[5] M. Barat, W. Lichten, Phys. Rev. A6, 211 (1972).
CP 35
57
Low-energy electron scattering from calcium
S. Gedeon and V. Lazur
Department of Theoretical Physics, Uzhgorod National University, 88000, Ukraine
E-mail: vfg-vik@yandex.ru
The B-spline R-matrix method (BSR) [1] is used to investigate the integrated cross sec-
tions (ICS) of elastic electron scattering from neutral calcium in the ultra-low energy
range from threshold to 0.5 eV. The close-coupling expansion includes 39 bound states of
neutral calcium, covering all states from the ground state to 4s8s 1S. The computational
model was described in detail in [2]. Brie°y, we generate an accurate target description by
using multicon-¯guration expansions, accounting for both valence and core-valence corre-
lations. Very importantly, we use term-dependent valence orbitals, which are optimized
individually for the various states of interest. We also account for relaxation of the core
orbitals, due to the deep penetration of the 3d orbital. As a result, we have a set of
normalized orthogonal one-electron orbitals for each state, but the orbitals from di®erent
sets do not form an orthonormal basis.
In this work we are compared the total and partial electron-impact cross sections from
Ca in the ultra-low energy region, calculated in two di®erent R-matrix approaches: the
present BSR method and R-matrix with pseudostates method (RMPS) [4]. As seen from
our calculations, basic di®erence between the cross sections in two R-matrix approaches
comes mainly from the dominated 2Po partial wave. In the same time, partial cross
sections for the 2Se and 2De partial waves in these two methods practically coincide.
In present work we also are compared the total BSR39 and RMPS cross sections with
experimental data of Romaniuk et al [3]. Overall, the agreement between both R-matrix
(BSR39 and RMPS) results and the experimental data [3] is satisfactory, although a few
discrepancies remain. We are compared 2Se, 2Po and 2De partial eigen-phases of electron-
impact scattering from Ca at low energies region between most recent calculations: BSR39
(the present calculation), RMPS [4] and method of static-exchange formalism [5]. Again,
the largest discrepancy between di®erent method was found for 2Po partial wave.
References
[1] O. Zatsarinny, Comput. Phys. Commun. 174, 273 (2006)
[2] O. Zatsarinny et al., Phys. Rev. A, 74, 052708 (2006)
[3] N.I. Romanyuk, O.B. Shpenik, I.P. Zapesochnyi, Pis'ma Zh. Eksp. Teor. Fiz., 32,
472 (1980) [JETP Lett. 32, 452 (1980)]
[4] K. Bartschat and H.R. Sadeghpour, J. Phys. B. 36, L9 (2003)
[5] J. Yuan, Zh. Zhang, Phys. Rev. A 42, 5363 (1990)
CP 36
58
Ab initio calculation of H+He+ electron transfer cross
sections
J. Loreau1, M. Desouter-Lecomte2, F. Rosmej3 and N. Vaeck1
1Service de Chimie Quantique, ULB, Brussels, Belgium
2LCP, Universit´e de Paris XI, Orsay, France
3Universit´e de Provence et CNRS, Centre St. J´erˆome, PIIM, Marseille, France
E-mail: jloreau@ulb.ac.be
Charge transfer mechanisms during collision processes between ions and neutral atoms
or molecules have recently received renewed attention, due to their role in the analysis of
laboratory and astrophysical plasmas.
To understand the physical processes that underlie plasma transport in magnetically
confined plasmas, spectroscopic methods have turned out to be very effective. One of the
most powerful of these methods is based on the space and time resolved observation of
line emission from impurity ions. However, under real experimental conditions of fusion
plasmas, the impurity ions interact with the plasma background H/D which leads to a
change of the radial distribution of the impurity ions due to charge exchange processes [1].
As helium is of particular interest for magnetically confined fusion research (production
from recombining alpha particles, ash transport), we calculate the charge exchange cross
sections between He+ and the H/D background for numerous channels at low energies (as
the electron temperature of divertor plasmas is much below an atomic unit). This implies
computational difficulties as a fully quantum mechanical description is needed.
We have used a quasi-molecular approach of the ion-atom collision based on the use of
conventional quantum-chemistry ab initio methods to obtain the potential energy surfaces
as well as the radial and rotational coupling matrix elements of the quasi-molecule HeH+.
The main problem encountered in this part of our work is the large number of excited
molecular states that need to be taken into account, necessitating the introduction of a
new basis of molecular orbitals.
A wave packet method is used to treat the curve-crossing dynamics resulting from the
failure of the Born-Oppenheimer approximation. A Gaussian wave packet is prepared
in the entrance channel and propagated on the coupled effective channels. The collision
matrix elements are computed from an analysis of the flux in the asymptotic region
by using properties of absorbing potentials, giving access to the charge exchange crosssections
[2]. We study different propagation methods, the influence of the rotational
couplings on the cross section as well as the problem of the origin-dependence of the
radial and rotational couplings.
References
[1] F. B. Rosmej, E. Stamm and V. S. Lisitsa. Europhys. Lett., 73, 342 (2006).
[2] E. Balo¨ıtcha, M. Desouter-Lecomte, M.-C. Bacchus-Montabonel and N. Vaeck. J. Chem.
Phys. 114, 8741 (2001).
CP 37
59
TDCS for inner-shell (e, 2e) processes on alkali and alkali
earth atoms Na, K, Be, Mg and Ca.
G. Purohit1, U Hitawala2 and K K Sud1, 2
1Department of Basic Sciences, Sir Padampat Singhania University
Bhatewar, Udaipur-313601, India
2Department of Physics, College of Science Campus,
M.L.S. University, Udaipur-313002, India
The study of electron impact ionization of atoms and molecules has been of interest, since the
early days of atomic and molecular physics, since the kinematics of this process are easily
controlled, and the electrons or ions resulting from the reaction can be observed with relative
ease. Since the first coincident measurement of (e, 2e) process on atoms by Erhardt et al[1] and
Amaldi et al[2] extensive theoretical and experimental investigations have been done to
measure the TDCS. A number of different theories have been developed, ranging from firstorder
Born calculations (and variations therein) which are successful at high incident energies
and asymmetric geometries [3] to second and higher order Born calculations, which are
successful at higher energies in more complex scattering geometries [4]. Variants on these
models include distorted wave Born approximations (DWBAs) that have achieved success
down to intermediate energies [58]. Recently U Hitawala et al [9] have calculated the (e, 2e)
triple differential cross section for alkali atoms Na and K and alkali earth atoms Mg and Ca.
We present in this communication the results of our calculation of triple differential cross
section (TDCS) for inner-shell (e, 2e) processes on alkali Na and K and alkali earth Be, Mg
and Ca atoms. We discuss the effects of incident electron energy, distortion, nuclear charge,
polarization, post collisional interaction etc. for the alkali and alkali earth targets investigated
by us.
References
[1] Ehrhardt H., Schulz M.,Tekaat T.and Willmann K. ,, Phys. Rev. Lett. 22, 89 (1969)
[2] Amaldi U., Egidi A., Marconnero R., and Pizzela G., Rev.Sci.Instrum. 40,
1001 (1969).
[3] Duguet A, Cherid M, Lahmam-Bennani A, Franz A and Klar H 1987 J.Phys.B: At.
Mol. Phys. 20 6145.
[4] Byron F.W. and Joachain C.J. 1989 Phys. Rep.179 211.
[5] Zhang X, Whelan C.T. and Walters H.R.J. 1990 J.Phys. B:At. Mol.Opt.Phys.23 L509.
[6] Rioual S., Pochat A., Gelebart F., Allan R.J., Whelan C.T. and Walters H.R.J., 1995.
J.Phys.B:At.Mol.Opt.Phys. 28 5317
[7] Rosel T, Roder J, Frost L., Jung K,Ehrhardt H.,Jones S.and Madison D.H. 1992
Phys.Rev. A46 2539
[8] Reid R.H.G., Bartchat K. and Raekar A 1998 J. Phys. B: At. Mol.Opt.Phys. 31 563.
[9] Hitawala U, Purohit G and Sud K K, J. Phy. B: At. Mol. Opt. Phys. (In Press), 2008
CP 38
60
The relativistic J-matrix method in scattering of
electrons from model potentials and small atoms
P. Syty
Department of Theoretical Physics And Quantum Informatics
Gda´nsk University of Technology
Narutowicza 11/12, 80-952 Gda´nsk, Poland
e-mail: sylas@mif.pg.gda.pl
The J-matrix method is an algebraic method in quantum scattering theory. It is based on
the fact that the radial kinetic energy operator is tridiagonal in some suitable bases. Nonrelativistic
version of the method was introduced in 1974 by Heller and Yamani [1] and
developed by Yamani and Fishman a year after [2]. Relativistic version was introduced
in 1998 by P. Horodecki [3].
The main advantage of the method is that it allows to calculate phase shifts for many
projectile energies with relatively small computational time. Also, the non-relativistic
limit in relativistic calculations is properly achieved. This fact was expected, since the
basis sets used in relativistic calculations satisfied the so called kinetic balance condition.
Some preliminary applications of relativistic J-matrix method to scattering have been
performed for some square-type potentials [4], using the newly developed Fortran 95 code
JMATRIX [5]. These tests proved that the method correctly describes the scattering
process.
Since these times, the JMATRIX code has been greatly extended and thoroughly tested.
In the present work we applied the code (in both non-relativistic and relativistic versions)
to calculate some scattering properties of electrons scattered from more complex
potentials, i.e. truncated Coulomb, Yukawa and Lenard-Jones potentials and more. In its
primary version, the JMATRIX program allowed for applying scattering potentials in analytical
forms only. Now the code has been extended, so it allows for applying scattering
potential given in any numerical form, i.e. taken from the GRASP92 code [6].
In conclusion, we present the calculated scattering phase shifts and cross sections for
many energies of the incident electrons, in cases of the analytical potentials mentioned
previously, as well as the numerical potentials of some small atoms. Also, we illustrate
the convergence process and describe some limitations of the method.
References
[1] E. Heller, H. Yamani, Phys. Rev. A 9, 1201 (1974)
[2] H. Yamani, L. Fishman, J. Math. Phys. 16, 410 (1975)
[3] P. Horodecki, Phys. Rev. A 62, 052716 (2000)
[4] P. Syty, TASK Quarterly 3 No. 3, 269 (1999)
[5] P. Syty, http://aqualung.mif.pg.gda.pl/jmatrix/
[6] F.A. Parpia, C. Froese Fischer, I.P. Grant, Comput. Phys. Commun. 94, 249 (1996)
CP 39
61
Multichannel atomic scattering and
confinement-induced resonances in waveguides
V.S. Melezhik1
,
, S. Saeidian2, P. Schmelcher2
,
3
1Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research,
Dubna, Russia
2Physikalisches Institut, Universit¨at Heidelberg, Philosophenweg 12, 69120 Heidelberg,
Germany
3Theoretische Chemie, Institut f¨ur Physikalische Chemie, Universit¨at Heidelberg, INF
229, 69120 Heidelberg, Germany
E-mail: melezhik@theor.jinr.ru
Pair atomic collisions in restricted geometry principally differ from the conventional two-
body free-space scattering. The restricted geometry leads to quantization of the atomic
motion in the direction of confinement. Another nontrivial effect for two distinguishable
quantum particles in a transverse harmonic trap is the confinement induced nonsepara-
bility of the center-of-mass (CM) and the relative motions. These effects can have exper-
imental mesoscopic developments for ultracold atoms in optical traps and atomic chips.
However, only simple analytical estimates were performed for the special case when iden-
tical atoms occupy lowest quantum states of a confining trap. In this zero-energy limit
the total atom-atom reflection has been predicted for the case of confinement-induced res-
onance (CIR)[1]. The origin of the CIR is a virtual transition from the ground transverse
state of the confining potential to the closed excited state during the collision[2].
We have investigated what happens if the energy range of colliding atoms encompasses
several quantum states of the confining potential[3]. The developed method permits
to analyze the transverse excitations/deexcitains and optimal conditions for avoiding
decoherence-inducing mechanisms at atomic collisions in waveguides. Special attention
was paid to the analysis of the CIRs for nonzero collision energies in the multimode
regimes. We have suggested a nontrivial extension of the CIRs theory developed so far
only for the single-mode regime at zero-energy limit. We have also fully took into account
the coupling between the CM and the relative motions in case of distinguishable atoms[4].
Specifically we explore in detail the recently discovered[5] dual CIR which is based on a
destructive interference mechanism leading to complete transmission in the waveguide
although the corresponding scattering in free space-exhibits strong s and p wave scatter-
ing. Possible applications include, e.g., cold and ultracold atom-atom collisions in atomic
waveguides and electron-impurity scattering in quantum wires.
References
[1] M. Olshanii, Phys. Rev. Lett. 81, 938 (1998).
[2] M.G. Moore, T. Begeman, and M. Olshanii, Phys. Rev. Lett. 91, 163201 (2003).
[3] S. Saeidian, V.S. Melezhik, and P. Schmelcher, Phys. Rev. A 77, 042721 (2008).
[4] V.S. Melezhik, J.I. Kim, and P. Schmelcher, Phys. Rev. A 76, 053611 (2007).
[5] J.I. Kim, V.S. Melezhik, and P. Schmelcher, Phys. Rev. Lett. 97, 193203 (2006).
CP 40
62
Excitation of forbidden 4d95s2 2D5/2 ! 4d105s 2P3/2
transition in In2+ ion at electron-In+ ion collisions
E.Ovcharenko, A.Gomonai, A.Imre, Yu.Hutych
Institute of Electron Physics, Ukrainian National Academy of Sciences,
Universitetska 21, 88017 Uzhgorod, Ukraine, e-mail: dep@mail.uzhgorod.ua
Here we report on the results of experimental investigation of excitation of the 4d95s2 2D5/2 !
4d105p 2P3/2 transition in In2+ ion at electron-In+ ion collisions, which is two-electron
dipole forbidden in pure LS-coupling. The experiment was carried out by a photon VUV
spectroscopy method using a crossed electron and ion beam technique. The specific features
of the experimental technique for studying the processes occurring at the inelastic
slow-electron collisions with indium ions are described in detail in [1].
The energy dependence of the effective excitation cross section for the In2+ spectral line
( 185.0 nm wavelength) was studied from the excitation threshold up to 100 eV according
to the following reaction scheme:
e + In+(4d105s2) 1So ! In2+(4d95s2) 2D5/2 + 2e
#
In2+(4d105p) 2P3/2 + h ( 185.0 nm)
A distinct structure in the above energy dependence within the energy range from the
threshold (Eex = 33.18 eV ) of the 4d95s2 2D5/2 level up to 50 eV was observed. Since
indium ion is a multielectron atomic system with pronounced correlation and relativistic
effects, this leads to strong mixing of both the ionic levels and the corresponding
autoionizing states (AIS).
The observed structure in the energy range from the threshold up to 40 eV may be
assigned to the contribution of the highest 4d95s2(2D3/2)np,mf AIS as well as to that of
the cascade transitions from the 4d106s−, 4d105d− and 4d106p− levels, while the structure
in the energy range 40 − 45 eV — to those from the 4d95s5p− levels of In2+ ion [2,3]
and decay of the In+ ion autoionizing states converging to the In2+ states. A broad
maximum above 50 eV is observed, which, we believe, reflects the mechanism of the
direct d-ionization process in In+ ion.
The result obtained, besides the fundamental significance, is of applied importance, since
In+ ion is isoelectronic to Cd atom, and the transition in In2+ ion at 185.0 nm is similar
to the well-known Cd+ 4d95s2 2D5/2 ! 4d105p 2P3/2 laser transition at 441.6 nm in the
He-Cd+ laser. As shown in [4], this radiative transition at 185.0 nm is the best candidate
for lasing in vacuum ultraviolet range.
References
[1] A.Gomonai, E.Ovcharenko, A.Imre, Yu.Hutych, Nucl. Instr. and Meth. in Phys. Res.
B 233, 250-254 (2005).
[2] D.Kilbane, J-P.Mosnier, E.T.Kennedy, J.T.Costello, P. van Kampen, J. Phys. B: At.
Mol. Opt. Phys. 39, 773-782 (2006).
[3] K.S.Bhatia, J. Phys. B: Atom. Molec. Phys. 11, 2421-2434 (1978).
[4] R.A.Lacy, A.C.Nilsson, R.L.Byer, J. Opt. Soc. Am. B 6, 1209-1216 (1989).
CP 41
63
The electron a±nity of Tungsten
A. O. Lindahl1, P. Andersson1, C. Diehl2, O. Forstner3, K. Wendt2, D. J. Pegg4 and
D. Hanstorp1
1Department of physics, University of Gothenburg, SE-412 96 Gothenburg, Sweden
2Institut fÄur Physik, Johannes Gutenberg-UniversitÄat, Mainz, 55099 Mainz, Germany
3Institut fÄur Isotopenforschung und Kernphysik, VERA-Laboratory, University of
Vienna, Kavalierstrakt A-1090 Wien
4Department of physics, University of Tennessee, Knoxville, Tennessee 37996, USA
E-mail: anton.lindahl@physics.gu.se
An improved value of the electron a±nity of Tungsten will be presented. The threshold
for photodetachment of W¡ forming neutral W in the ground state was investigated by
measuring the total photodetachment cross section. The electron a±nity was obtained
from a ¯t of the Wigner law in the threshold region.
The experiment showed a photodetachment signal below the threshold associated with
detachment from the ground state negative ions. This observation indicate the existence
of a previously unobserved bound excited state in W¡.
The experiment was performed using the ion beam apparatus GUNILLA (GÄoteborg Uni-
versity Negative Ion Linear Laser Apparatus). This apparatus, which previously has been
used to investigate light negative ions, has been redesigned in order to obtain a higher
mass resolution and better transmission. The W¡ measurement is an example of the high
mass capabilities of the new apparatus. The ion optical design and performance of the
apparatus will be described in some detail.
CP 42
64
High resolution measurements of molybdenum
L-shell satellites and hypersatellites excited by
oxygen and neon ions
M. Czarnota1, D. Bana¶s1, M. Berset2, D. Chmielewska4, J.-Cl. Dousse2, J. Hoszowska2,
Y.-P. Maillard2, O. Mauron2, M. Pajek1, M. Polasik3, P. A. Raboud2, J. Rzadkiewicz4,
K. SÃlabkowska3, Z. Sujkowski4
1Institute of Physics, Jan Kochanowski University, 25-406 Kielce, Poland
2Department of Physics, University of Fribourg, CH-1700 Fribourg, Switzerland
3Faculty of Chemistry, Nicolaus Copernicus University, 87-100 Toru¶n, Poland
4SoÃltan Institute for Nuclear Studies, 05-400 Otwock-¶Swierk, Poland
The observation of L-shell hypersatellites of molybdenum L®1;2 (L3!M4;5) and L¯1
(L2!M4) x-ray transitions excited in ion-atom collisions are reported. The high-resolution
measurements of x-ray satellites and hypersatellites emitted from multiply ionized molyb-
denum give access to study the ¯ne details of a structure of multi-vacancy states in mid-Z
atoms. Such experiments are important for testing the atomic structure calculations, in
particular, the relativistic multi-con¯guration Dirac-Fock (MCDF) approach, including
the Breit and QED corrections. In this way the structure calculations can be tested for
excited atoms having up to several vacancies in inner shells.
The high-resolution measurements of Mo L®1;2 and L¯1 x-ray satellites excited by oxygen
and neon ions were performed at the Philips cyclotron in the Paul Scherrer Institute (PSI)
in Villigen, Switzerland, using O6+ and Ne6+ ions with energy 278.6 MeV and 177.9 MeV
respectively. The excited L-x-rays were measured with a high-resolution di®raction von
Hamos spectrometer [1] having an instrumental energy resolution of 0.6 eV for studied
x-rays. The absolute energy calibration of the spectrometer was about 0.3 eV [2].
In order to interpret the observed structure of L®1;2 x-ray satellites and hypersatellites
and L¯1 satellites in molybdenum the relativistic MCDF calculations [3] were performed
for multi-vacancy con¯gurations (L¡lM¡mN¡n) expected to be excited in collisions with
O and Ne ions. These included the x-ray diagram (L¡1), satellite (L¡1M¡mN¡n), hy-
persatellite (L¡2) and hypersatellite satellite (L¡2M¡mN¡n) transitions, with m and n
indicating a number of vacancies in the M- and N-shell in the initial state.
To our knowledge, this is the ¯rst experimental observation of a direct ion excitation of
the L-shell hypersatellites in molybdenum, which is, additionally, clearly interpreted by
a complex MCDF calculations performed revealing their internal structure corresponding
to the multi-vacancy (L¡2N¡nM¡m) con¯gurations.
References
[1] J. Hoszowska et al., Nucl. Instr. and Meth. A376, 129 (1996)
[2] M. Czarnota et al., Nucl. Instr. and Meth. B205, 133 (2003)
[3] M. Polasik, Phys. Rev. A52, 227 (1995)
CP 43
65
Electron-impact scattering on boron
L. Bandurina1, V. Gedeon2
1Institute of Electron Physics, Uzhgorod, 88026, Ukraine
2Department of Theoretical Physics, Uzhgorod National University, 88000, Ukraine
E-mail: vfg-vik@yandex.ru
The B-spline R-matrix (BSR) method [1] is used to investigate electron-impact scattering
on neutral boron over an energy range from threshold to 60 eV. A multi-configuration
Hartree-Fock method with nonorthogonal orbitals is employed to generate an accurate representation
of the target wavefunctions. The present close-coupling expansion includes the
8 bound states of neutral boron derived from the 1s22s22p, 1s22s2p2, 1s22s23l (l = 0, 1, 2)
configurations, plus twenty pseudo-states. The primary difficulties in the target structure
and coupling to the target continuum for B arise from the 2s2p2 configuration. The
orbitals in this configuration have been corrected here through configuration interaction
with the 2s2pnl and 2p2nl sequences. These same pseudostate expansions also provide
for coupling of 2s2p2 configuration with the target continuum.
Results for angle-integrated and angle-differential cross sections and effective collision
strengths are presented for important transitions from the ground state 2s22p 2Po and
the excited 2s2p2 4P and 2s23s 2S states. Results for angle-integrated cross sections are
compared with experimental data Kuchenev and Smirnov [2] and predictions from other
R-matrix calculations Marchalant and Bartschat [3] and Balance et al [4]. Our predictions
for the angle-integrated cross sections show some discrepancies with those from previous
calculations carried out with the standard R-matrix with pseudostates (RMPS) approach
in a similar scattering model [3] and [4]. These discrepancies are mostly due to the different
target descriptions, with the present one giving some better agreement with experiment
[5] for energy levels. The excitation cross sections exhibit prominent resonance structures
in the low-energy region. The energy positions, widths, and classifications for the detected
resonances are presented.
References
[1] O. Zatsarinny, Comput. Phys. Commun. 174, 273 (2006)
[2] A.K. Kuchenev, Yu.M. Smirnov, Opt. spectrosc. 51, 116 (1981)
[3] P.J. Marchalant and K. Bartschat, J. Phys. B 30, 4373 (1997)
[4] C.P. Ballance, D.C. Griffin, K.A. Berrington and N.R. Badnell, J. Phys. B 40, 1131
(2007)
[5] NIST Atomic Spectra Database, http://physics.nist.gov
CP 44
66
Observation of He – He collisions using
the anticrossing method
E. Baszanowska1, R. Drozdowski1, P. Kaminski1, G. von Oppen2
1University of Gdansk, Institute of Experimental Physics, Wita Stwosza 57,
80-952 Gdansk, Poland
2Technische Universitat Berlin, Hardenbergstr. 36, D - 110623 Berlin, Germany
Excitation of He atoms by He+-ion impact has been analyzed for a large range of projectile
energies. Of particular interest was the intermediate energy region, where the velocity of
the projectiles is comparable with the Bohr velocity of the bound electrons of the He-target
atoms. It was shown [1] that it is this transition region where the excitation mechanism
changes from a process, which essentially can be described within the framework of the
molecular orbital model, to a process describable using the Born approximation. In this
transition region, saddle dynamics [2] and electron promotion based on the atomic Paul
trap mechanism [3] are suitable to describe this excitation process.
In the present investigations we analyzed the excitation of He atoms by He-atom impact
in the intermediate-energy range. The post-collisional states contain components with
different parity. Therefore the charge distribution of the electronic clouds of the excited
atoms can be asymmetric. The charge distribution was determined by using anticrossing
spectroscopy. By applying electric fields to the collision volume the singlet and triplet 1snl
states with l ≥ 2 can be tuned to near degeneracy. Due to the spin-orbit coupling, the
Stark substates with the same rotational and reflection symmetry are strongly mixed. This
mixing gives rise to the formation of anticrossings which could be detected as resonancelike
variations of the intensity of the emitted spectral lines. In the experimental setup, the
intensity of the selected spectral lines emitted by the collisionally excited He atoms in a
direction perpendicular to the crossed beams is measured as a function of an electric field
applied parallel and antiparallel to the projectile beam. Then, if the population numbers
of the anticrossing singlet and triplet levels are not equal, an anticrossing intensity peak
is observed. The amplitudes of these anticrossing peaks provide information about the
charge distribution of the collisionally excited state. Additionally, the spectrum of the
emitted light was measured for various selected values of the field strength.
The symmetric He-He collision system is composed of four equivalent electrons and two
identical nuclei. In collisions, the target atom as well as the projectile atom can be excited.
Singlet states are populated by direct excitation, but triplet states only by electron
exchange. The evolution of the He-He system is expected to be more complex than the
He+-He evolution, where only one electron is promoted on the two-centre potential of the
He+ ions. But our measurements show that for intermediate-energy He-He collisions the
excited He-target atoms possess electric dipole moments, that is, the charge distributions
of the electronic clouds are asymmetric. Since in the He+-He collisions this asymmetry is
mainly due to a coherent population of the l ≥ 2 states, we conclude that the Paul-trap
mechanism probably plays an important role also in these He-He collisions.
This work was supported by the BW grants of the University of Gdansk: 5200-5-0048-8 and 5200-5-0483-8
[1] M. Busch, R. Drozdowski, Th. Ludwig and G. von Oppen, J. Phys. B 37, 2903 (2004)
[2] J. M. Rost, J.S. Briggs, J. Phys. B 24, 4293 (1991).
[3] G. von Oppen, Europhys. Lett. 27, 279 (1994)
CP 45
67
Spin-exchange cross sections at the interaction
between ground state rubidium and metastable
helium atoms
V.A.Kartoshkin, S.P.Dmitriev, and N.A.Dovator
A.F.Io®e Physico-Technical Institute, Russian Academy of Sciences,
Polytechnical str.26, 194021 St.-Petersburg, Russia
E-mail: victor.kart@mail.io®e.ru.
At the interaction between spin-polarized excited atom and ground state alkaline metal
atom in gas discharge elastic and inelastic processes take place simultaneously. In such
a case these two processes in°uence on each other giving rise to a change of the cross
section's value for the elastic process. It means, that besides the chemiionization of the
ground state atom at the expense of the atom's excitation energy (inelastic process), an
exchange of electrons was shown to be possible without a great depolarization (s.c. spin
exchange, or elastic process) [1].
Up to the present there was only one experimental work where the spin-exchange and
chemiionization cross sections were measured . The experiment has been done for He*
-Cs system [1] .
In order to determine interesting us cross sections we have to separate two simultaneously
occurring spin-dependent processes. In the experiment on optical polarization of the
helium metastable atoms these atoms may be aligned or oriented along a static magnetic
¯eld. It can be shown that the rates of the decay of the orientation < SHe >z and
alignment < QHe >zz of metastable atoms depend on chemiionization and spin-exchange
processes as follows
1=¿or = ¼±for = N(1/3 Cci + 1/2 Cse),
1=¿al = ¼±fal = N(1/3 Cci + 3/2 Cse),
here N is the alkali metal atom concentration, Cci and Cse - are the chemiionization
and spin-exchange rate constants, ±for and ±fal are the widths of the orientation and
alignment signals, 1=¿i is the rate of the decay of the metastable atom's orientation or
alignment. As one can see from Eqs., the contribution to the width of the magnetic
resonance line for aligned helium atoms should be di®erent from that of oriented atoms.
This di®erence makes it possible to determine the rate constants of the two simultaneously
occurring processes. In this work the experiment on optical orientation of atoms has been
done for He* -Rb system. It was established that the rate constant for spin exchange
(Cse) in collision of metastable 23S1 helium atom with a rubidium atom in 62S1=2 ground
state equals (1:8 § 0:8)10¡9cm3s¡1. The rate constant for chemiionization of rubidium
atoms by metastable helium atoms (Cci) was determined at the same time to be (3:1 §
0:6)10¡9cm3s¡1.
References
[1] S.P.Dmitriev, N.A.Dovator, and V.A.Kartoshkin, JETP Lett., 66, 151-154 (1997)
CP 46
68
Spin exchange and redistribution of the
spin-polarization at the interaction between ground
state alkali atoms and nitrogen atoms in gas
discharge
V.A.Kartoshkin
A.F.Io®e Physico-Technical Institute, Russian Academy of Sciences,
Polytechnical str.26, 194021 St.-Petersburg, Russia.
E-mail: victor.kart@mail.io®e.ru.
In gas discharge an e®ective spin-exchange process is proceeding between spin-polarized
ground state alkali atoms and ground state's nitrogen atoms, that demonstrates a con-
servation of total electron spin and, consequently, a transfer of angular momentum from
an ensemble of the previously spin-polarized alkali atoms to the electronic part of the N
atoms in 4S3=2 state [1].
Consider the behavior of a quasi-molecular system consists of the nitrogen atom with
electron spin angular momentum SA = 3/2, and alkali atom with electron spin angular
momentum SB = 1/2. If the spins of the two interacting particles be SA and SB, there
are two molecular states Vi, which correspond to di®erent values of the total spin (S)
of the quasi-molecule. In our case there are two molecular terms Vq(S = 2) and Vt(S
= 1). Therefore the spin-exchange process can be described by two cross sections ¾1
and ¾2 corresponding to the change in the magnetic quantum numbers of the interacting
particles, respectively, 3/2,1/2 *) 3/2,-1/2; -3/2,1/2 *) -1/2,-1/2;3/2,-1/2 *) 1/2,1/2; -
1/2,-1/2 *) -3/2,1/2 and -1/2,-1/2 *) 1/2,-1/2; 1/2,-1/2 *)-1/2,1/2. It can be shown that
the cross sections are determined as
¾1=3/4jfq ¡ ftj2
and
¾2=1/4jfq ¡ ftj2,
where fq and fq are the scattering amplitudes on the quintet Vtq and triplet Vt terms.
At the recombination of the spin-polarized N atoms the polarization can be transmitted
to the N2 molecules. The mechanism of the N atoms recombination involves nitrogen
atom recombination into the N2(A5P
) state. At the conservation of angular momentum
during the interaction the transfer of angular momentum from atoms to molecules takes
place being to the spin-polarization of the N2 molecule. The redistribution of angular
momentum between electron spin system and rotational system in the N2 molecule results
in rotational polarization of the molecule too.
In this work the kinetics of optical orientation and spin-exchange collisions between alkali
and nitrogen atoms have been investigated and equations, describing the evolutions of
the polarized moments have been received. The equations describing the redistribution
of the polarization in the N2 have been received too.
References
[1] S.P.Dmitriev, N.A.Dovator, and V.A.Kartoshkin, Optika i spektr.(in Russian) 104,
752-755 (2008)
CP 47
69
Large angle e-He scattering — coincidence
experiment with magnetic angle changer
L. K losowski, M. Piwi´nski, D. Dziczek, K. Pleskacz and S. Chwirot
Institute of Physics, Nicolaus Copernicus University
Grudzi ¸ adzka 5/7, 87-100 Toru´n, Poland
E-mail: lklos@fizyka.umk.pl
Electron impact excitation of 21P1 state of He has been the first collisional process investigated
using electron–photon coincidence technique. Since then, similar studies approaching
the limit of quantum mechanically complete experiments have been carried out for
other collisional systems and stimulated a progress in both theoretical and experimental
studies of electronic collisions. At the same time all that work has suffered from lack
of experimental data on scattering parameters at large scattering angles. Such measurements
could not be carried out for seemingly simple reason finite dimensions of electron
beam sources and energy analysers.
We have shown recently [1] that such measurements could be performed if trajectories
of electrons were suitably modified by a so-called magnetic angle changer (MAC) [2, 3],
successfully used by other groups in measurements of differential cross-sections [4].
We are presenting new experimental data for electron impact excitation of 21P1 state
of He atoms by 100 eV electrons. The measurements were carried out using angular
correlations technique with application of MAC and yielded first experimental data on
scattering parameters for large scattering angles up to 180 .
Ab initio predictions are fairly consistent for low scattering angles where they are also in
good agreement with available experimental data while serious discrepancies exist at large
scattering angles [5, 6], where a lack of experimental data made it difficult to improve the
consistency of various theoretical models.
References
[1] L. K losowski, M. Piwi´nski, D. Dziczek, K. Wi´sniewska, S. Chwirot, Meas. Sci. Technol.
18, 3801 (2007)
[2] M. Zubek, N. Gulley, G. C. King, F. H. Read, J. Phys. B: At. Mol. Opt. Phys. 29,
L239 (1996)
[3] F. Read, J. Channing, Rev. Sci. Instrum. 67, 2372 (1996)
[4] B. Mielewska, Rad. Phys. Chem. 76, 418 (2007)
[5] N. Andersen, J. W. Gallagher, I. V. Hertel, Phys. Rep. 165, 1 (1988)
[6] D. V. Fursa, I. Bray, Phys. Rev. A, 52, 1279 (1995)
CP 48
70
Di usion coe cient and viriel coe cient of Krypton
Atoms in a Argon Gas at Low and Moderate
Temperature
C. Benseddik M.T. Bouazza and M. Bouledroua
1Physics Department and LAMA, Badji Mokhtar University, Annaba, Algeria
2Facult e de M edecine and LPR, Badji Mokhtar University, Annaba, Algeria
In the present work, using the Chapman-Enskog method for dilute gases, we have cal-
culated the di usion coefcients of ground krypton atoms in a very weakly ionized bu er
gas of argon. The calculations are carried out quantum mechanically. To do so, we
have constructed the potential energy curve, relative to the 1 + molecular state, through
which a Kr approaches Ar. The data points upon which the construction is made are
smoothly connected to the long- and short-range forms. They are supposed to behave
analytically like 1=Rn and exp(􀀀 R), respectively. The spectroscopic data, Re = 7:42a0
and De = 510:084 Eh; are in accordance with what is available in literature. The isotopic
e ect has also been examined. The classical second virial coefcients are also calculated for
several temperatures. Our computation yields a value of the Boyle temperature of about
TB 545:223K. Generally, the results of the transport parameters with temperature
show an excellent agreement with the available experimental data; the discrepancies do
not exceed 5%.
CP 49
71
A theoretical report on ultracold collisions of two
monatomic cesium
M.T. Bouazza1 and M. Bouledroua2
1Physics Department, Badji Mokhtar University, Annaba, Algeria
2Facult e de M edecine and LPR, Badji Mokhtar University, Annaba, Algeria
In this work, we are interested in the elastic collisions of two 133Cs monatoms at very
low temperatures. The behavior of such cold atoms is characterized by two physical pa-
rameters: the scattering length andtheeffectiverangere. The study begins by the con-
struction of the potential-energy curves of the two possible molecular symmetries, namely,
X1 +
g and a1 +
u , through which two ground 133Cs(6s) interact. The exchange potential
of the form AR exp(􀀀 R) is also taken into account. These constructed interatomic
potentials are further introduced into the radial-wave equation to determine numerically
the elastic phase shifts needed in the calculations of the total and partial cross sections.
The scattering length and the eective range are therefore computed by using quantum-
mechanical and semiclassical approaches.
CP 50
72
Tomography of laser cooled atoms in MOT using
Rydberg state excitation
V.M.Entin , I.I.Beterov, I.I.Ryabtsev, D.B.Tretyakov
Institute of Semiconductor Physics, Pr. Lavrentyeva 13, 630090, Novosibirsk, Russia
E-mail: ventin@isp.nsc.ru
The position selective dimensional study of laser cooled atoms in magnetooptical trap
(MOT) usually performed using optical detection. Nevertheless many years ago was
developed more precise method of imaging of atomic beams using ionization of atoms and
detection of produced electrons and ions using secondary electron multipliers[1]. This
technique demonstrates possibility to detect of a few atoms that making it attractive
for experiments with small density of atoms[2]. In the current paper we have performed
experiment directed to observe di erence in the space distribution of Rb atoms in MOT
in the rst exited state (5P) caused various selection (dark or bright) of the repumping
transition.
In the our experiment we produced cold atomic cloud of 107 Rb atoms cooled using
conventional MOT setup. After that atoms were optically exited to the Rydberg state
using cascade transitions: 5S!5P!8S (decay)! 6P!nS;nD (n 37). First excitation
pulse (5P!8S) was performed by pulsed dye laser (Rodamine G6, 615 nm). Second,
pulse of the Ti:Sa laser at 740 nm was applied to the transitions 6P! nS;nD. Laser
beams were focused to the trap and crossed under angle near 90 degree. The Rydberg
atoms were detected using selective eld ionization technique. The Ti:Sa laser beam
was 1D scanned across atomic cloud using de ector based on galvanometer driven lens.
The optical de ection unit was controlled using computer. It allows us to make position
sensitive measurement of the Rydberg state excitation rate.
Averaged data on counts of Rydberg atoms was used to determine population of the 5P
state in separate parts of the atomic cloud. Experimental tomography data obtained for
locking of the repumping laser to the bright or dark transition, show di erent 5P 1D
pro les of the trap. Observed phenomena was in agreement with theoretical predictions
and our previous results[3].
This technique is non-destructive method of measurement of exited state distribution in
MOT. It could be used also for space selective reading(or writing) of quantum states for
quantum computing experiments in optical lattices.
This work was supported by the Russian Academy of Sciences.
References
[1] N. F. Ramsey, "Molecular Beams", Clarendon Press, Oxford, (1956).
[2] I. I. Ryabtsev, D. B. Tretyakov, I. I. Beterov, and V. M. Entin, Phys. Rev. A, 2007,
v.76, p.012722.
[3] V. M. Entin, I. I. Ryabtsev, JETP Letters, 2004, v.80, pp.161-166.
CP 51
73
Spatial light modulators for cold atom manipulation
Michael Mestre, Fabienne Diry, Bruno Viaris de Lesegno and Laurence Pruvost
Laboratoire Aimé Cotton, CNRS II, bat 505, campus d’Orsay
91405 Orsay, France
E-mail: laurence.pruvost@lac.u-psud.fr
Spatial Light Modulators (SLM’s) are programmable optical elements that can act as
dynamical phase holograms on laser beams. Thus, a laser beam can be shaped into a
pattern which is the Fourier transform of the hologram. It provides a flexible method to
create dipole potentials in order to manipulate small objects. In this context, our group
is investigating experiments using SLM’s for cold atom cloud manipulation.
First we have focused on response time and diffraction pattern quality issues. We have
demonstrated a device involving a SLM and an acousto-optic modulator (AOM/SLM)
with a refresh time of some micro-seconds and without bleed effect during the hologram
changes [1]. This device would be well-suited for cold atom manipulation with
time-dependent dipole potentials. We have also studied different algorithms to calculate
holograms.
Then, we have experimented the method on cold rubidium atoms, by applying a blue
detuned laser shaped into a hollow Laguerre-Gaussian beam. Such a profile is obtained
by applying a helical-phase hologram to the laser beam. The cold atoms have been guided
during their fall due to gravity, into the dark region of the Laguerre-Gaussian mode. Being
far-detuned from resonance and dark where the atoms spend most of their time, the light
field causes little scattering-induced losses and guiding is efficient. The efficiency is studied
versus the detuning and the order of the Laguerre-Gaussian beam and is compared to a
model for the atom capture into the two-dimensional potential.
Future applications of this technique will be presented and discussed in the context of
cold atoms or Bose-Einstein condensates experiments.
References
[1] Fast reconfigurable and transient-less holographic beam-shaping realized by a AOMSLM
device, M. Mestre, B. Viaris de Lesegno, R. Farcy, L. Pruvost, J. Bourderionnet, A.
Delboulbé, B. Loiseaux, and, D. Dolfi ; Eur. Phys. J. Appl. Phys. 40, 269—274 (2007).
CP 52
74
All-optical Bose-Einstein Condensation of Chromium
atoms and rf spectroscopy of cold Cr2 molecules
Q. Beaufils1, R. Chicireanu1, T. Zanon1, A. Crubellier2, B. Laburthe-Tolra1, E.
Mar´echal1, L. Vernac1, J.-C. Keller1 and O. Gorceix 1
1Laboratoire de Physique des Lasers, Universit´e Paris-Nord, 99 avenue Jean-Baptiste
Cl´ement, 93430-Villetaneuse, France
2Laboratoire Aim´e Cotton, Bat 505, Campus d’Orsay, 91405 Orsay, France
E-mail: olivier.gorceix@univ-paris13.fr
The study of quantum gases made of chromium atoms is compelling for several reasons.
Being accessible to laser manipulation, chromium has a most abundant bosonic isotope
52Cr and a 9-percent abundant fermionic isotope 53Cr. Most importantly, Cr atoms carry
an exceptionally large magnetic moment of 6 μB. Consequently, Cr provides a valuable
tool to study the physics of dipolar quantum gases as demonstrated in [1].
We present our recent achievement of a chromium Bose-Einstein Condensation (Cr-BEC)
[2] using an all-optical procedure along with two innovative techniques:
- continuous accumulation of metastable 52Cr atoms in a mixed optical and magnetic trap
[3];
- fast and intense rf sweeps to average to zero the magnetic potential and optimize the
transfer efficiency from the Cr-MOT to the optical trap [4].
We also report on the rf spectroscopy and association of weakly bound Cr2 molecules
in the decatriplet 13 +
g state. These latter experiments are performed in the vicinity
of a d-wave Feshbach resonance at low magnetic field. Though the association rate is
at present fairly low, we can study the spectroscopic properties of these cold trapped
high-spin chromium molecules.
This work is supported by Conseil R´egional Ile-de-France, MENESR, CNRS, ANR, EU
and IFRAF.
References
[1] T. Lahaye et al. Nature, 448, 672 (2007)
[2] Q. Beaufils et al., arXiv :0712.3521
[3] R. Chicireanu et al., Eur. Phys. J. D, 45, 189 (2007)
[4] Q. Beaufils et al., arXiv :0711.0663
CP 53
75
Entangled photons from excitonic decay
in arti cial atoms
Marek Seliger, Ulrich Hohenester, and Gernot Pfanner
Institute for Physics, Karl-Franzens-University Graz, 8010 Graz, Austria
Email: marek.seliger@uni-graz.at
We theoretically investigate the production of polarization-entangled photons through the
biexciton cascade decay in a single semiconductor quantum dot. Entangled photons play a
key role in quantum communication and computation schemes. Furthermore, generation
of single or entangled photons on demand has widespread applications in experiments on
a single photon level. Semiconductor quantum dots are very attractive for these devices
due to the strong con nement of charge carriers and the resulting atomlike properties.
A biexciton decays radiatively through two intermediate exciton states. If these are
degenerate, the two decay paths di er in polarization but are indistinguishable otherwise
leading to polarization-entangled photons [1]. This ideal performance is usually spoiled
by the electron-hole exchange interaction splitting the intermediate exciton states by a
small amount and attaching a which-path information to the photon frequencies.
We discuss strategies to accomplish a high degree of entanglement, despite the exciton
nestructure splitting: energetical alignment of the two exciton states [2] or post-selection
of photons [3; 4]. We show how passive optical elements (spectral ltering and time shifts)
at a single photon level a ect the quantum information encoded in the photon wavepacket.
Here the solid state environment plays a crucial role in the e ective measurement of the
intermediate exciton states [5]. Our results suggest that protocols for solid-state based
quantum cryptography are more strict than previously thought.
References
[1] O. Benson, et al., Phys. Rev. Lett. 84, 2513 (2000).
[2] R.M. Stevenson, et al., Nature (London) 439, 179 (2006).
[3] N. Akopian, et al., Phys. Rev. Lett. 96, 130501 (2006).
[4] J.E. Avron, et al., Phys. Rev. Lett. 100, 120501 (2008).
[5] U. Hohenester, G. Pfanner, and M. Seliger, Phys. Rev. Lett. 99, 47402 (2007).
CP 54
76
Optimizing number sqeezing when splitting a
mesoscopic condensate
J. Grond1, U. Hohenester1 and J. Schmiedmayer2
1 Institut fur Physik, Karl-Franzens-Universitat Graz,
Universitatsplatz 5, 8010 Graz, Austria,
2 Atominstitut der osterreischischen Universitaten, Technische Universitat Wien,
Stadionallee 2, 1020 Wien, Austria
E-mail: julian.grond@uni-graz.at
An atom interferometer can be built using Bose Einstein condensates, con ned in magnetic
traps, which are split by continously transforming the trapping potential [1]. In order to
minimize phase di usion, due to the nonlinearity originating from atom-atom interactions
in the condensate, number squeezing of the atoms in the wells is required. Squeezing
occurs when tunneling becomes small due to the nonlinear interaction which favors a
sharp number distribution in each well.
In adiabatic scenarios, squeezing is severely limited by the timescales of the tunneling
dynamics, and therefore non-adiabatic strategies are favorable. In this contribution we
show that optimal control theory (OCT) [2] allows to devise control strategies which
signi cantly outperform adiabatic schemes. We rst discuss number squeezing in the
framework of a generic two-mode model, and give an intuitive physical explanation for
the OCT control strategy. For realistic magnetic microtraps, it becomes important to
include a non-adiabatic wave function evolution beyond the generic two-mode model. In
this work we describe the dynamical evolution of the two orbitals occupied by the atoms
within the MCTDHB equations [3], which are based on a variational principle.
Our results cover several squeezing time scales as well as di erent numbers of atoms in
the condensate. We compare adiabatic to non-adiabatic splitting with simple control and
optimal control. By using OCT, we can handle non-adiabatic wave function evolution,
and obtain number squeezed states on much shorter time scales in comparison to other
strategies.
[1] T. Schumm, S. Ho erberth, L. M. Andersson, S. Wildermuth, S. Groth, I. Bar-Joseph,
J. Schmiedmayer, and P. Kruger, Nat. Phys. 1, 57 (2005);
G.-B. Jo, Y. Shin, S. Will, T.A. Pasquini, M. Saba, W. Ketterle, D. E. Pritchard, M.
Vengalattore, and M. Prentiss, Phys. Rev. Lett 98, 030407 (2007);
A. D. Cronin, J. Schmiedmayer and D. E. Pritchard, quant-ph/arXiv:0712.3703 .
[2] U. Hohenester, P. K. Rekdal, A. Borz, and J. Schmiedmayer, Phys. Rev. A 75, 023602
(2007).
[3] O. E. Alon, A. I. Streltsov and L. S. Cederbaum, Phys. Rev. A 77, 033613 (2008).
CP 55
77
Breakdown of integrability in a
quasi-one-dimensional ultracold bosonic gas
I.E. Mazets1,2, T. Schumm1 and J. Schmiedmayer1
1Atominstitut der ¨ Osterreichischen Universit¨aten, TU Wien, A–1020 Vienna, Austria
2A.F. Ioffe Physico-Technical Institute, 194021 St. Petersburg, Russia
We argue that virtual excitations of higher radial modes result in effective three-body
collisions that violate integrability in a quasi 1 dimensional atomic Bose gas in a tightly
confining waveguide and give rise to thermalization [1]. After adiabatic elimination of
virtually excited radial modes, we obtain the Hamiltonian
ˆH
3b = −8 log
4
3
¯h!r 2
s
Z
dz ˆ † ˆ † ˆ † ˆ ˆ ˆ
of this effective three-body elastic process. Here !r is the fundamental frequency of the
radial confinement, s is the 3D s-wave scattering length. The corresponding collision
rate per atom in a non-degenerate gas is
􀀀3b = C3b!r 2, = n1D 2
s
q
m!r/¯h,
where C3b 5.57, m is the atomic mass, n1D is the 1D atomic number density. We
demonstrate that, for typical experimental conditions [2] ( 0.007), the three-body processes
dominate over thermalization via real radial mode excitation in the most energetic
pairwise collisions for temperatures kBT < 0.4 ¯h!r. We compare our theoretical findings
to the experimental results [3] and stress the further inhibition of thermalization in a one
dimensional gas by correlations (atomic anti-bunching due to strong repulsion).
To summarize, a radially confined atomic gas is never perfectly 1D, and radial motion
can be excited, either in reality or virtually even if both its temperature and chemical
potential are below ¯h!r. Such quasi-1D systems exhibit more rich physics than predicted
by the Lieb-Liniger model [4].
References
[1] I. Mazets, T. Schumm and J. Schmiedmayer, arXiv:0802.1701 (2008)
[2] S. Hofferberth et al., Nature 449, 324 (2007);
S. Hofferberth, et al., Nature Physics (in print), arXiv: cond-mat/0710.1575.
[3] T. Kinoshita, T. Wenger, and D.S. Weiss, Nature 440, 900 (2006).
[4] E.H. Lieb and W. Liniger, Phys. Rev. 130, 1605 (1963);
E.H. Lieb, Phys. Rev. 130, 1616 (1963).
CP 56
78
Light-shift tomography in an optical-dipole trap
J-F. Cl ement, J-P. Brantut, M. Robert de St Vincent, G. Varoquaux, R.A. Nyman, A.
Aspect, T. Bourdel and P. Bouyer
Laboratoire Charles Fabry de l'Institut d'Optique, Campus Polytechnique, RD 128,
91127 Palaiseau France
We report on light-shift tomography of a cloud of 87Rb in a far-detuned optical-dipole
trap. At this wavelength, the excited state of the cooling transition of 87Rb is strongly
red-shifted, which enables us to perform energy-resolved imaging. We take advantage of
this speci c feature by using it in two di erent situations.
(i) Mapping of the optical potential. Starting with a cold cloud with a smooth density
pro le, we switch on a trapping laser at 1565 nm, and immediately take an absorption
image of the atoms in the presence of the trap. By scanning the probe laser frequency,
we perform a mapping of the equal light-shift regions.
(ii) Measurement of the atomic potential energy distribution. By counting the total num-
ber of atoms detected at a given probe detuning, we directly measure the number of atoms
having a given potential energy in the trap. We follow the evolution of this atomic distri-
bution for a trapped cloud during the free-evaporation process, starting from a strongly
out-of-equilibrium situation and relaxing towards a thermal distribution.
Using a spatially-varying light eld, this technique could be used to adress atoms situated
in regions which size is smaller than the laser wavelength.
CP 57
79
Matter wave interferometry with K2 molecules
S. Liu1, I. Sherstov2, H. Kn¨ockel1, Chr. Lisdat2, E. Tiemann1
1Institut f¨ur Quantenoptik, Leibniz Universit¨at Hannover, D-30167 Hannover, Germany
2Physikalisch-Technische Bundesanstalt, Bundesallee 100, D-38116 Braunschweig
We operate a matter wave interferometer on a beam of K2 molecules in a Ramsey-Bord´e
configuration [1]. The two exits of this interferometer, with molecules in either the excited
state or the ground state, allow distinct detection schemes for the matter wave
interference. While observation of the fluorescence of excited state molecules shows the
matter wave interferences superimposed on a complicated incoherent background due to
the molecular hyperfine structure, detection of ground state molecules behind the interferometer,
exciting them with a fixed frequency laser, gives the interference pattern
on a simple symmetric background due to a single hyperfine component. Under certain
geometric conditions any of the observed matter wave interferences is composed of two distinct
structures, a Ramsey-Bord´e interference structure from four laser beams employed
as beam splitters for the matter wave, and an additional Ramsey interference structure
formed by only two laser beams acting as beam splitters.
The higher stability of the Ramsey-Bord´e setup due to cancellation of phase drifts and
fluctuations in corresponding laser beams promises the Ramsey-Bord´e interferometer as
a sensitive detector for collisions between molecules and ground state K atoms in the
particle beam, when the collisions modify the phase and the damping of the interference
pattern. The detection was done by deflecting atoms out of the molecular beam by a
resonant laser field, thus switching the experiment between atom-molecule collisions and
no collisions.
For a better understanding of the Ramsey interferences, we detected the ground state
exit in two different distances near the beam splitters and further away downstream of
the molecular beam. With active stabilization of the relative phases of the laser beams
used as beam splitters the Ramsey interference shows a good phase stability. The better
contrast of the Ramsey matter wave interferences as compared to the Ramsey-Bord´e setup
recommends this method as well suited for further experimental applications.
We will introduce between the beam splitters a laser field near resonant to a molecular
transition from either the excited state or the ground state to another state. Such experiment
allows to determine the transition matrix element of the corresponding molecular
transition. By changing the collision characteristics of the K atoms by exciting them to
Rydberg states, the collisions between potassium atoms and molecules will be investigated.
The present status of the matter wave experiment will be presented.
References
[1] Chr. Lisdat, M. Frank, H. Kn¨ockel, M.-L. Almazor, E. Tiemann, Eur. Phys. J. D 12,
235-240 (2000)
CP 58
80
A magnetic lens for cold atoms tuned by a rf ¯eld
E. Mar¶echal, B. Laburthe-Tolra, L. Vernac, J.-C. Keller, and O. Gorceix
Laboratoire de Physique des Lasers, UMR 7538 CNRS, Universit¶e Paris Nord, 99
Avenue J.-B. Cl¶ement, 93430 Villetaneuse, France
Email : marechal@galilee.univ-paris13.fr
The combination of static inhomogeneous magnetic ¯elds with a strong resonant rf ¯eld
has been recently used in many groups to realize new trapping geometries, like double well
potentials, or bubble-like traps [1; 2]. A rf ¯eld allows indeed to distort static magnetic
potentials into new 'adiabatic potentials' that can be continuously tailored and tuned by
changing the rf ¯eld parameters [3]. Another possibility is to use rf ¯elds to change the
properties of atom-optics elements like magnetic lenses or magnetic mirrors. Following
this idea, we have experimentally investigated how the focal length of a magnetic lens can
be tuned with rf.
The experiment is performed using a spin polarized cloud of cold cesium atoms. The rf
dressed lens is realized with two components : a static magnetic lens, made of a simple
coil, and a rf ¯eld. The inhomogeneous static ¯eld de¯nes a surface where atoms are
resonant with the rf ¯eld. As atoms cross this surface, their spin is reversed, and the
e®ect of the lens (initially converging or diverging, depending on the initial polarization)
is reversed. The magnetic lens is separated by the rf interaction surface into two parts,
and become equivalent to a doublet. The position of the interaction region, and therefore
the focal length of the doublet can be tuned by changing the rf frequency.
After a 72 cm free fall, atoms cross the lens center, and are focused typically 10 cm
below, in a 500 ¹m 1=e2 diameter spot. We show that by changing the rf frequency
between 100 MHz and 250 MHz, the 10 cm magnetic focal length can be tuned over
§2 cm. Depending on the rf antenna position, the magnetic lens can be made more
converging than without rf, and can be changed by increasing the rf frequency from a
converging lens to a converging mirror. The magnetic lens, in combination with a strong
rf ¯eld, is conveniently described in the dressed-atom picture. The probability that atoms
follow the adiabatic rf-dressed potentials can be evaluated by a Landau-Zener model, that
determines the rf power requirements to get a lens with good performances. Under our
experimental conditions, 10 W of rf is necessary.
Our experimental investigation of the rf-dressed lens, supported by numerical simulations
is presented in [4]. This rf-dressing procedure can be combined with the well-developed
integrated atom chip technology, to add coherent control to magnetic atom chips.
We acknowledge ¯nancial support by IFRAF (MOCA project).
References
[1] Y. Colombe, E. Knyazchyan, O. Morizot, B. Mercier, V. Lorent, H. Perrin, Europhys.
Lett. 67, 593 (2004)
[2] I. Lesanovsky, T. Schumm, S. Ho®erberth, L. M. Andersson, P. KrÄuger, J. Schmied-
mayer, Phys. Rev. A 73, 033619 (2006)
[3] O. Zobay, B. M. Garraway, Phys. Rev. Lett. 86, 1195 (2001)
[4] E. Mar¶echal, B. Laburthe-Tolra, L. Vernac, J.-C. Keller, O. Gorceix, Appl. Phys. B,
91, 233 (2008)
CP 59
81
Stability and d -wave collapse of a dipolar
Bose-Einstein condensate
T. Pfau , Th. Lahaye, J. Metz, B. Fr¨ohlich, T. Koch, A. Griesmaier
5. Physikalisches Institut, Universit¨at Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart,
Germany
t.pfau@physik.uni-stuttgart.de
Although the phenomenon of Bose–Einstein condensation is a purely statistical effect that
also appears in an ideal gas, the physics of Bose–Einstein condensates (BECs) of dilute
gases is considerably enriched by the presence of interactions among the atoms. In usual
experiments with BECs, the only relevant interaction is the isotropic and short-range
contact interaction, which is described by a single parameter, the scattering length a. In
contrast, the dipole–dipole interaction between particles possessing an electric or magnetic
dipole moment is of long range character and anisotropic, which gives rise to new
phenomena [1]. Most prominently, the stability of a dipolar BEC depends not only on
the value of the scattering length a, but also strongly on the geometry of the external
trapping potential. Here, we report on the experimental investigation of the stability of a
dipolar BEC of 52Cr as a function of the scattering length and the trap aspect ratio. We
find good agreement with a universal stability threshold arising from a simple theoretical
model. Using a pancake-shaped trap with the dipoles oriented along the short axis of
the trap, we are able to tune the scattering length to zero, stabilizing a purely dipolar
quantum gas [2].
We also experimentally investigate the collapse dynamics of a dipolar condensate of 52Cr
atoms when the s-wave scattering length characterizing the contact interaction is reduced
below a critical value. A complex dynamics, involving an anisotropic, d-wave symmetric
explosion of the condensate, is observed on time scales significantly shorter than the trap
period. At the same time, the condensate atom number decreases abruptly during the
collapse. We compare our experimental results with numerical simulations of the threedimensional
Gross-Pitaevskii equation, including the contact and dipolar interactions as
well as three-body losses. The simulations indicate that the collapse is accompanied by
the formation of two vortex rings with opposite circulations.
References
[1] Th. Lahaye, T. Koch, B. Fr¨ohlich, M. Fattori, J. Metz, A. Griesmaier, S. Giovanazzi,
T. Pfau ”Strong dipolar effects in a quantum ferrofluid” Nature 448, 672 (2007).
[2] T. Koch, Th. Lahaye, J. Metz, B. Fr¨ohlich, A. Griesmaier, T. Pfau ”Stabilizing a
purely dipolar quantum gas against collapse”, Nature Physics 4, 218 (2008).
CP 60
82
Blue cooling transitions of thulium atom
K. Chebakov, N. Kolachevsky, A. Akimov, I. Tolstikhina, P. Rodionov, S. Kanorsky, and
V. Sorokin
P.N. Lebedev Physics Institute, Leninsky prosp. 53, Moscow, 119991 Russia
It has been shown recently that Yb [1] and Er [2] atoms from the lanthanides group can
be e±ciently laser-cooled using strong transitions near 400 nm. Degenerate Fermi gases
of ytterbium have been also recently demonstrated using laser-cooling based technic [3].
Our goal was to investigate the possibility of laser cooling of Tm atom. Among other
lanthanides, thulium possesses relatively simple level structure.Moreover, it has only one
stable isotope 169Tm with a nuclear spin of I = 1/2 which makes possible to use schemes
for sub-Doppler cooling. Laser-cooled thulium is a favorable candidate for optical clocks
applications, since the forbidden transition between the ¯ne structure sublevels (Jg =
5=2) ¡ (J0
g = 7=2) of the ground state 4f136s2 (¸ = 1:14 micron) has a spectral width
of approximately 1 Hz. The collisional shift of such kind of transitions in lanthanides is
suppressed because of the outer closed 6s2 shell [4], which allows for precision spectroscopy
in a dense atomic cloud.
We studied two candidates for cooling transitions from the ground state 4f136s2 (Jg = 7=2)
to the states 4f12(3H5)5d3=26s2 (Je = 9=2) at 410.6 nm and 4f12(3F4)5d5=26s2 (Je = 9=2)
at 420.4 nm. By means of saturation absorption spectroscopy, we measured the hyper¯ne
structure and rates of these transitions. We evaluated the life times of appropriate excited
levels as 15.9(8) ns and 48(6) ns, respectively. Decay rates from these levels to neighboring
opposite-parity levels were evaluated by means of Hartree-Fock calculations [5]. The
fraction of atoms which do not return to the ground state is about 10¡5 and 5 ¢ 10¡4
for the 410.6 nm and 420.4 nm transitions respectively. We conclude that the strong
transition at 410.6 nm with relative slow leakage rate can be used for the e±cient cooling
of Tm I.
We also measured hyper¯ne structure of two nearby transitions from the ground state to
the states 4f13(2F7=2)6s6p(1P1) (Je = 5=2) at 409.4 nm and 4f12(3F4)5d5=26s2 (Je = 7=2)
at 418.9 nm, which can be used for ¤-type excitation of ¸ = 1:14 ¹m transition.
References
[1] R. Maruyama et al., Phys. Rev. A 68, 011403(R), (2003).
[2] J.J. McClelland and J.L. Hansen, Phys. Rev. Lett. 96, 143005 (2006).
[3] Takeshi Fukuhara, Yosuke Takasu, Mitsutaka Kumakura, and Yoshiro Takahashi Phys.
Rev. Lett. 98, 030401 (2007).
[4] C.I. Hancox, S.C. Doret, M.T. Hummon, L. Luo, J.M. Doyle, Nature, 431, 281 (2004).
[5] R.D. Cowan, The Theory of Atomic Structure and Spectra, Berkeley, CA: University
of California Press, (1981).
CP 61
83
Free-fall expansion of nite-temperature
Bose-Einstein condensed gas in the non
Thomas-Fermi regime
J. Szczepkowski1;2, R. Abdoul1;5, R. Gartman1;5,
W. Gawlik1;4, M. Witkowski1;3, J. Zachorowski1;4, M. Zawada1;5
1National Laboratory for Atomic Molecular and Optical Physics
Grudzi adzka 5, 87-100 Toru n, Poland,
2Institute of Physics, Pomeranian University
76-200 S lupsk, Arciszewskiego 22B, Poland,
3Institute of Physics, University of Opole
Oleska 48, 45-052 Opole, Poland,
4Institute of Physics, Jagiellonian University
Reymonta 4, 30-057 Krak ow, Poland,
5Institute of Physics, Nicolaus Copernicus University
Grudzi adzka 5, 87-100 Toru n, Poland.
E-mail: jszczepkowski@wp.pl
Since 1995 we have opportunity to experimental study degenerate and non-degenerate
trapped atomic gases at ultra low temperatures. At nite temperatures the free expansion
of the dilute gas leads to spatially thermal distinct and condensed phases. The thermal
phase is negligible at temperatures much smaller than the critical temperature Tc, and
behavior of the condensed part is mainly determined by the interplay between the trapping
potential and the atomic interactions. At the temperatures close to Tc there are usually
more thermal dilute gases than the condensed one. In this case also interactions between
two phases, thermal and condensed, have a ect on the behavior of the condensed fraction.
The F. Gerbier et all[1] show in uence of this interaction to evolution of free falling Bose-
Einstein condensate (BEC) in the presence of the thermal fraction for the condensate
with assumption the Thomas-Fermi regime in the condensate phase.
In our experiment we analyze a free expansion of 87Rb BEC release from the magnetic
trap[1] with presence of the thermal part dilute atomic gases using standard time-of- ight
technique. As a result we note the dependence between condensed aspect-ratio (ratio
of axial to radial radii) of the condensate as a function of amount of the condensate
fraction in the dilute atomic gas, after 15 ms free expansion. We investigate region where
the Thomas-Fermi regime is not hold in BEC. The aspect ratio dependence results from
interplay between condensed and non-condensed fraction of the dilute gas and a small
number of the atoms in the condensed fraction at the temperature close to Tc.
References
[1] F. Bylicki,W Gawlik, W. Jastrz ebski, A. Noga, J. Szczepkowski, M. Witkowski,
J. Zachorowski, M. Zawada, Acta Phys. Polon. A 113, 691 (2008)
[2]F. Gerbier, J. H. Thywissen, S. Richard, M. Hugbart, P. Bouyer, and A. Aspect, Phys.
Rev. A , 70, 013607 (2004)
CP 62
84
Resonance Interaction between Cold Rb Atoms and
a Frequency Comb
E. Tereschenko1;2, M. Egorov1;2, A. Sokolov1;2, A. Akimov1;2, V. Sorokin1;2,
N. Kolachevky1;2
1 P.N. Lebedev Physics Institute, Leninsky prosp. 53, 119991 Moscow, Russia
2 Moscow Institute of Physics and Technology, 141704 Dolgoprudny, Russia
A long life time of atoms in a magneto-optical trap (MOT) makes it a powerful tool to
study interactions with optical ¯elds processing small cross sections (see e.g. [1]). Since
the life time in MOT can reach a few seconds, even processes with characteristic rates of
1 s¡1 can be easily analyzed if they result in losses of trapped atoms.
We have investigated the interaction of laser-cooled 87Rb atoms in a MOT with a femtosec-
ond (fs) laser radiation in the spectral region 760-820 nm. We show that in a wide range
of average intensities of the fs laser ¯eld (< 300W/cm2) the dominating process is the cas-
cade ionization. In this case the femtosecond radiation interacts with the atomic ensemble
both as spectrally-narrow components (a frequency comb) and as a powerful ionizing laser
¯eld. Atoms excited by a single mode of a frequency comb from the 5P3=2(F = 3) to the
5D5=2(F = 2; 3; 4) hyper¯ne sublevels are consequently ionized by a full power of the fs
laser from the 5D level to the continuum. By tuning the repetition rate frep of the fs
laser we observe the periodic spectrum in the MOT luminescence at 780nm (the cooling
transition) reproducing the hyper¯ne structure of the 5D level (see Fig. 1a).
Figure 1: (a) | MOT luminescence signal vs. detuning of the fs laser repetition rate ±frep.
(b) | dependency of the MOT loading rate on the fs laser power.
We have quantitatively analyzed the ionization of the 5D5=2 level by monitoring the load-
ing rate of the MOT at di®erent powers of the fs laser radiation (Fig. 1b) using an auxiliary
cw laser locked to the 5P3=2(F = 3) ! 5D5=2(F = 4) at 776 nm. A sensitive method al-
lowing accurate determination of the 5/2 5D level population is developed [2].
[1] O. Marago, D. Ciampini, F. Fuso, E. Arimondo, C. Gabbanini, and S. T. Manson,
Phys. Rev. A 57, R4110 (1998).
CP 63
85
Optical tailoring of spatial distribution of the BEC
and non-degenerate cold atoms.
Non-periodic optical lattice
M. Witkowski1,3, R. Gartman1,5, W. Gawlik1,4, J. Szczepkowski1,2, M. Zawada1,5
1National Laboratory for Atomic Molecular and Optical Physics
Grudziadzka 5, 87-100 Torun, Poland,
2Institute of Physics, Pomeranian University
76-200 Słupsk, Arciszewskiego 22B, Poland,
3Institute of Physics, University of Opole
Oleska 48, 45-052 Opole, Poland,
4Institute of Physics, Jagiellonian University
Reymonta 4, 30-057 Kraków, Poland,
5Institute of Physics, Nicolaus Copernicus University
Grudziadzka 5, 87-100 Torun, Poland.
E-mail: mwitkowski@uni.opole.pl
Optical lattices are the instruments of great importance in many fields of atomic physics
like manipulating of neutral particles, quantum computing, etc. The common method of
getting a periodic optical lattice is to use the interference of two or more laser beams
which form an array of periodic light-shift potentials.
We demonstrate a new method of creating an optical lattice of either non-degenerate
cold atoms or Bose-Einstein condensates. The lattice is obtained when the cloud of cold
atoms is illuminated by a focused, off-resonant laser beam split into several beams by
a diffraction process. The resulting lattice is non-periodic.
In our experiment we used 87Rb atoms trapped in the magnetic trap of the Ioffe-Pritchard
type. This is an anisotropic and harmonic trap characterized by frequencies: radial
!r = 2 · 137 Hz and axial !a = 2 · 12 Hz [1]. The laser beam of a frequency close
to the D1 line of 87Rb was used in the experiment.
We analyze the evolution of that kind of lattice either in a magnetic trap or during time of
flight after the atoms are released from the trap. Due to interactions between atoms and
near resonant light the characteristic regular structure of atoms appears. We characterize
the basic properties of this structure in two cases of a nondegenerate atom cloud and
a BEC. In particular, we analyze the effect of the laser frequency on the formation
process of optical lattice.
Our method can be another way of studying phenomena where an optical lattice is a necessary
instrument. The presented method of creating the optical lattice might be an
alternative to the standard counter-propagating laser beams method.
References
[1] F. Bylicki, W. Gawlik, W. Jastrzebski, A. Noga, J. Szczepkowski, M. Witkowski,
J. Zachorowski, M. Zawada, Acta Phys. Polon. A 113, 691 (2008).
CP 64
86
Laser techniques for atom-scale technologies
F. Tantussi, N. Por¯do, F. Prescimone, V. Mangasuli,
M. Allegrini, E. Arimondo and F. Fuso
CNISM and Dipartimento di Fisica Enrico Fermi, Universitµa di Pisa
Largo Bruno Pontecorvo 3, I-56127 Pisa, Italy
e-mail: fuso@df.unipi.it
Among the various applications envisioned for laser-cooling and manipulation of neu-
tral atoms, those dealing with nanostructure fabrication appear particularly challeng-
ing. Atomic NanoFabrication (ANF [1]) demonstrated production of regular nanopat-
terns through the occurrence of dipolar forces and the consequent spatial segregation of
an atom beam (optical mask). Recently, large technological interest is being attributed
to develop methods for the controlled deposition of few, eventually single, atoms onto
a surface. The realization of atom-scale technologies is one of the major challenges in
realizing novel nanodevices from single atomic, or molecular, elements, with a potentially
large impact in emerging areas such as nanophotonics, spintronics, quantum computation
systems, advanced biomedical applications.
We have developed an experimental setup aimed at directly depositing few atoms onto a
surface under laser-manipulation control. Core of the setup is a Cesium beam produced
out of a modi¯ed magneto-optical trap (MOT) [2] which exhibits sub-thermal kinetic
energy in the longitudinal direction and, after due collimation by 2D optical molasses,
shows a residual divergence in the mrad range. The setup has been already employed
in resist-assisted fabrication of regular arrays of nanotrenches (45 nm wide) onto Gold
through interaction with a 1D optical mask [3]. We are presently exploring the regime of
low °ux, low temperature direct deposition [4]. Thanks to an in-situ Scanning Tunnelling
Microscope (STM), sample features can be investigated at the atomic scale. A variety of
substrates has been used, ranging through Graphite to organic self-assembled monolayers.
Deposition of stable isolated Cesium nanostructures consisting of a few atoms has been
demonstrated, with metal-like electronic features. Due to the small longitudinal velocity
of the atoms, relatively long interaction times with the optical mask can be achieved,
leading to the occurrence of a pure channelling regime for the guided atom trajectories.
In the low surface coverage regime, the interaction produces both a spatial modulation
of the deposited atom density and a peculiar nanoisland morphology, which acquires a
cigar-like shape oriented in agreement with the optical mask. Results suggest however that
nanostructure features are ruled by a complicated interplay between laser-manipulation
and local properties of the substrate, involving a variety of surface physics e®ects to be
still completely unravelled.
Financial support by Fondazione Cassa di Risparmio di Pisa (PR/05/137) is gratefully
acknowledged.
References
[1] For a review see, for instance, D. Meschede and H. Metcalf, J. Phys. D 36, R17 (2003).
[2] A. Camposeo, et al., Opt. Commun. 200, 231 (2001).
[3] C. O'Dwyer, et al., Nanotechnology 16, 1536 (2005).
[4] F. Tantussi, et al., Mat. Sci. Eng. C 27, 1418 (2007).
CP 65
87
Emission from Silicon/Gold nanoparticle systems
M. Bassu1, F. Tantussi1, L. Strambini2, G. Barillaro2, M. Allegrini1, F. Fuso1
1 CNISM and Dipartimento di Fisica E. Fermi, Universitµa di Pisa, I-56127 Pisa, Italy
2 Dipartimento di Ingegneria dell'Informazione, Universitµa di Pisa, I-56122 Pisa, Italy
e-mail: fuso@df.unipi.it
Investigation of systems comprising metal nanoparticles (NPs) with plasmonic features
and light-emitting Silicon is stimulated by distinct motivations. First of all, integration
of NPs with materials and technologies used in conventional optoelectronics represents
an important step towards practical applications in the emerging areas of plasmonics
and nanophotonics [1]; moreover, spectroscopy of such systems opens the way to study
the interplay between distinct sub-systems with speci¯c optical properties. When prop-
erly designed, such interplay can be used to tailor the system behavior, for instance by
modifying the emission spectrum or the overall quantum e±ciency.
We have analyzed photoluminescence (PL) of samples produced by a novel anodization-
free electrochemical etching of Si catalyzed by Gold NPs. The process is based on the
production of Au NPs through rapid thermal annealing of a thin Au ¯lm evaporated
onto a Si wafer. Etching in a H2O2:HF (10:1) solution then leads to mesopore structures
diverging from Au NPs. Microscopy of the produced samples demonstrates the achieve-
ment of a porous-Si network embedding NPs typically sized in the few tens of nanometers
range. The technique, which can be considered as a variant of the HOME-HF process
[2], exhibits technologically appealing features: for instance, no anodization is required,
favoring integration with conventional Si technologies; by lithographical de¯nition of the
pristine Au ¯lm, porization can be easily achieved in prede¯ned patterns, thus leading to
nanostructured light-emitting samples.
Samples produced in various conditions, starting from either p- or n-doped Si, have been
analyzed upon both cw and pulsed laser excitation in the violet/UV range, at room and
low temperature. Results demonstrate e±cient PL in the visible, peaked around 600-650
nm. Comparison with samples which underwent an Au-removal process based on chemical
etching suggests that NPs play a prominent role in ruling the emission: after Au-removal
the emission intensity gets remarkably smaller and is spectrally shifted. The role of NPs
is well con¯rmed by simulations of the plasmon resonance for Au NPs in the actual con-
ditions (size distribution and dielectric constant of the embedding medium) experienced
in the samples, resulting peaked slightly above 600 nm. Analysis of the emission lifetime
as a function of the temperature reveals a puzzling behavior which suggests an intriguing
contribution of both radiative and non-radiative phenomena. Nanoscopic investigations
have been started based on scanning near-¯eld optical microscopy (SNOM), a technique
already proven successful with similar systems [3]. Results show distinctive features for
the near-¯eld maps which describe scattering and emission, simultaneously acquired with
our SNOM. Interpretation, still in progress, will shed light on the interaction between
NPs and Si occurring in the near-¯eld.
References
[1] For a review see, for instance, S. Maier, et al., Nature Materials 2, 229 (2003).
[2] X. Li and P.W. Bohn, Appl. Phys. Lett. 77, 2572 (2000).
[3] F. Fuso, et al., J. Appl. Phys. 91, 5495 (2002).
CP 66
88
As3d core level studies of (GaMn)As annealed under
As capping
I.Ulfat1,2, J.Adell1,2, J.Sadowski2,3, L.Ilver1 and J.Kanski1
1Department of Applied Physics, Chalmers University of Technology, Goteborg, Sweden
2MAX-Lab, Lund University, Lund, Sweden
3Institute of Physics, Polish Academy of Sciences, Warszawa, Poland
In recent years the DMS (GaMn)As has fascinated research community as a promising
candidate for spintronic application. It is of exacting significance due to both its compatibility
with existing III-V technology and great progress in improving its magnetic
properties. Being a supersaturated solid solution of Mn in GaAs matrix, fabricated by
low temperature molecular beam epitaxy (LT-MBE) ,the material contains a high density
of various defects compensating Mn acceptors. This results in the deterioration of
its magnetic properties as the ferromagnetism in (GaMn)As occurs due to an indirect
exchange between magnetic moments of Mn ions mediated by free holes .
The ferromagnetic state of (GaMn)As is known to be established by post growth annealing.
Until recently such annealing has been carried out in air or nitrogen.However, once
the sample has been exposed to air, its surface cannot be restored. This means that
(GaMn)As annealed in this way are not useful for further epitaxial overgrowth to be included
in multilayer structures. In order to meet this requirement an innovative annealing
procedure was devised in which the reactive medium (oxygen or nitrogen) is replaced by
a surface layer of amorphous As thus removing the interstitial Mn [1].
To observe the presence of reacted surface layer containing As, As3d core level spectra
taken at BL41 at Swedish National Synchrotron Radiation Facility (MAX-lab) have been
analyzed. In order to identify the contribution from the reacted layer, spectra from pure
GaAs and (GaMn)As subjected to post growth annealing have been investigated. Our
data indicate that the interface between the out-diffusing Mn and the As capping results
in a uniform epitaxial continued layer structure of MnAs. This is rather unexpected as
zincblende MnAs is known to be unstable, and MBE growth of MnAs on GaAs normally
results in the formation of clusters with hexagonal structure.
[1] M.Adell et al., Appl.Phys.Lett.6, 112501 (2005)
CP 67
89
Pulsed laser Deposition Simulation for Graphite
Target using Mont-Carlo Method
N. Alinejad, M. Jahangiri, F. Izadi
Physics and Nuclear Fusion Research School, Tehran, Iran
Pulsed laser deposition method for producing thin lms is investigated. This deposition
method include several stages such as absorption of the laser beam in the target material,
evaporation of the material producing plume of atoms or molecules, strong interaction
of the laser beam with the plumb to produce plasmas, and nally deposition of atoms
or molecules on the substrate surface. The growth of the thin lm in the initial stage
is simulated using Mont Carlo method. Our simulation indicated that by decreasing the
duration of the pulse together with the decrease in laser energy, the thin lm growth is
steady so that the uniform and homogenous layer is produced. Keywords: pulsed laser
deposition, thin lms, simulation, Graphite PACS No: 310.0310, 140.0140
CP 68
90
Precision Measurement of the 3He-3H mass ratio
with the MPIK/UW-PTMS
Christoph Diehl1, David Pinegar1, Robert S. Van Dyck Jr.2 and Klaus Blaum1
1Max-Planck-Institut fur Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg, Germany
2Department of Physics, University of Washington, Seattle, WA 98195-1560, USA
e-mail: christoph.diehl@mpi-hd.mpg.de
The precise determination of the 3He-3H mass ratio is of utmost importance for the
measurement of the electron anti-neutrino mass performed by the Karlsruhe Tritium
Neutrino experiment (KATRIN) [1]. By determining this ratio to an uncertainty of 1
part in 1011, systematic errors of the endpoint energy in the -decay of 3H to 3He can be
checked in the data analysis of KATRIN [2].
To reach this precision, a Penning Trap Mass Spectrometer (MPIK/UW-PTMS) was
constructed at the University of Washington [3], which is now transferred to the Max-
Planck-Institute for Nuclear Physics in Heidelberg in the new division \Stored and Cooled
Ions".
The Penning trap technique allows for the most precise mass measurements (< 10􀀀10
relative uncertainty for stable ions) by the determination of the eigenfrequencies of a
single stored ion in a superposition of an electric and magnetic eld [4].
Special design features of the MPIK/UW-PTMS are the utilization of an external ion
source and the double trap con guration. The external Penning ion source e ciently ion-
izes the helium and tritium gas. Also, external ion creation can give superior elimination
of unwanted ion species compared to the previously utilized internal eld emission tips.
The design as a double Penning trap allows for several monitoring capabilities (e.g. using
one trap as a voltage reference), as well as for a faster measurement procedure. This
should help to avoid problems due to long-term drifts in the experimental conditions.
The MPIK/UW-PTMS will be set into operation in Heidelberg by the end of 2008. We
will present the design of the setup as it was constructed and tested at the University of
Washington.
References
[1] Ch. Weinheimer, Nucl. Phys. B 168, 5 (2007)
[2] E. W. Otten, J. Bonn, Ch. Weinheimer, Int. J. Mass Spec. 251, 173 (2006)
[3] D. B. Pinegar, S. L. Zafonte, R. S. Van Dyck Jr., Hyperf. Int. 174, 47 (2007)
[4] K. Blaum, Phys. Rep. 425, 1 (2006)
CP 69
91
CP 70
92
Isotope shift in the electron affinity of sulfur:
observation and theory
T. Carette1, C. Drag 2, C. Blondel2, C. Delsart2,
C. Froese Fischer3, M. Godefroid1 and O. Scharf1
1 Service de Chimie Quantique et Photophysique, Universit´e Libre de Bruxelles -
CP160/09, B 1050 Brussels, Belgium
2 Laboratoire Aim´e-Cotton, CNRS, Universit´e Paris-sud, F-91405 ORSAY cedex, France
3 Department of Electrical Engineering and Computer Science, Box 1679B, Vanderbilt
University, Nashville TN 37235, USA
Photodetachment microscopy [1] was performed on a beam of S− generated by a hot
cathode discharge in a mixture of 98% Ar and 2% CS2, with the sulfur isotopes in natural
abundances. Isotope 34 was selected by a Wien velocity filter. Laser excitation was
provided by a CW ring laser operating with the Rhodamine 590 dye. The laser wavenumber
was measured by an Angstr¨om WS-U lambdameter, with an accuracy better
than 10−3 cm−1. Subtracting the photoelectron energy found by analysing the electron
interferogram from the photon energy, one can determine the electron affinity eA. The
result for eA(34S) is 16 752.978(10) cm−1, to be compared to the previously measured
eA(32S)=16 752.976(4) cm−1 [2]. Technical correlations between the two measurements
lets the isotope shift exp = eA(34S) − eA(32S) be a little more accurate than the more
imprecise electron affinity. Numerically exp = +0.002(8) cm−1, in wich the (2 ) error
bars leave room for a normal or anomalous result.
Ab initio calculations of the isotope shift on the electron affinity from the infinite-mass
systems S−/S were carried out, adopting the multiconfiguration Hartree-Fock (MCHF)
approach using the ATSP2K package [3]. Our model includes in a systematic way valence
correlation, limiting the core to the n=2 shell. The one-electron orbitals are optimized
using a single- and double- multi-reference expansions. Configuration-iteraction (CI) calculations
including up to 6·105 configuration state functions were performed in order to
complete the convergence patterns of the S− energy, resulting in a unextrapolated nonrelativistic
electron affinity of eA(1S) = 16 987(44)cm−1. The theoretical isotope shift
value theor = eA(34S) − eA(32S) = −0.0022(2)cm−1 is found to be rather small but
definitely negative. The analysis of the various contributions reveals a very large specific
mass shift that counterbalances the normal mass shift, while the positive field shift is
smaller than the total mass contribution by one order of magnitude.
[1] C. Blondel, C. Delsart, and F. Dulieu. Phys. Rev. Lett. 77 (1996) 3755.
[2] C. Blondel, W. Chaibi, C. Delsart, C. Drag, F. Goldfarb, and S. Kr¨oger. Eur. Phys. J. D
33 (2005) 335 ; C. Blondel, W. Chaibi, C. Delsart, and C. Drag. J. Phys. B: At. Mol.
Opt. Phys. 39 (2006) 1409;
[3] C. Froese Fischer, G. Tachiev, G. Gaigalas, and M. R. Godefroid. Comp. Phys. Com.
176(2007)559
CP 71
93
Theoretical study of attosecond chronoscopy of
strong-¯eld atomic photoionization
A.K. Kazansky1;2 and N.M. Kabachnik3;4
1 Fock Institute of Physics, State University of Sankt Petersburg, Sankt Petersburg
198504, Russia
2 Donostia International Physics Center, E-20018 San Sebastian/Donostia, Basque
Country, Spain
3 FakultÄat fÄur Physik, UniversitÄat Bielefeld, D-33615 Bielefeld, Germany
4 Institute of Nuclear Physics, Moscow State University, Moscow 119991, Russia
A model which describes the time evolution of strong-¯eld photoionization of atoms is
presented. Based on the numerical solution of the non-stationary SchrÄodinger equation,
the model allows one to predict and to interpret the results of experiments on double
photoionization of atoms by a combined action of a very short (attosecond) XUV pulse
and a few-cycle IR pulse of a powerful laser at various delay times between the two
pulses. Depending on the binding energy of the ionized electron, two types of process
are considered. If the electron is tightly bound (Ne case), the XUV pulse ionizes the
atom and shakes up another (outer) electron to an excited state, which is subsequently
ionized by the strong IR ¯eld. For an atom with a weakly bound outer electron (Li case),
the IR ¯eld ionizes the latter, while the XUV pulse, ionizing the inner shell, terminates
(or suppresses) the strong ¯eld ionization. In both cases the yield of doubly ionized ions
strongly depends on the delay time between the two pulses, revealing "steps", oscillations
and other features which characterize the time evolution of the ionization process. The
presented model describes qualitatively the results of recent experiments on Ne [1].
References
[1] M. Uiberacker et al., Nature 446, 627 (2007)
CP 72
94
Generation of ultra-short X-ray pulses in cluster
system during ionization by femto-second optical
pulse
A.V. Glushkov12, O.Yu. Khetselius2, A.V. Loboda2
1Institute for Spectroscopy of Russian Academy of Sciences, Troitsk, 142090, Russia
2Odessa University, P.O.Box 24a, Odessa-9, 65009
We present the results of modelling generation of the atto-second VUV and X-ray pulses
during ionization of atomic and cluster systems by femto-second optical laser pulse. The
concrete data are received for the Ar cluster response, the molecular 2D H2+ response
for di®erent inter nuclear distances (R=2.5, 3.5, 7.4, 16a.u.) with smoothed Coulomb
potential and atomic (H) response (spectral dependence) under ionization of the system
by femto-second optical pulse [1-4]. Our calculation show that the generation of the atto-
second X-ray pulses in the cluster system is more e®ective and pro¯table (as minimum
the 2-3 orders) than in similar molecular atomic one. The generation of the atto-second
pulses in the molecular system is more pro¯table too (as minimum the 1-2 orders) than
in similar atomic one. The last achievements in this ¯eld demonstrate a possibility of
construction of the compact X-ray radiation sources.
References
[1] A. Glushkov, L.N. Ivanov, J. Phys.B. 26, L379 (1993)
[2] A. Glushkov, O. Khetselius, Recent Adv. in Theory of Phys. and Chem. Syst.
(Springer). 18 (2008)
[3] A. Glushkov, et al, Int. Journ. Quant. Chem. 99, 889 (2004)
[4] A. Glushkov, O. Khetselius, S. Malinovskaya, Mol. Phys. 24 (2008)
CP 73
95
Long-term stability of high- nesse Fabry-Perot
resonators made from Ultra-Low-Expansion glass
J. Alnis1, A. Matveev1;2, C. Parthey1, N. Kolachevsky1;2, T.W. Hansch1;3
1 MPI fur Quantenoptik, Hans-Kopfermann Str. 1, 85748 Garching, Germany
2 P.N. Lebedev Physics Institute, Leninsky prosp. 53, 119991 Moscow, Russia
3 Ludwig-Maximilians University,Geschwister-Scholl-Platz 1, 80539 Munich, Germany
Sub-Hz line width lasers limited by thermal noise of the high- nesse Fabry-Perot (FP) resonators
used for laser stabilization are very important for optical atomic clock community.
Usually thermal noise limited operation can be achieved for time scales of approximately
1 min and for longer time scales the drift starts to dominate. The most suitable material
for making a stable FP cavity (spacer and mirror substrates) is Ultra Low Expansion
glass (ULE). In this work we report on our observations of the long-term stability of ULE
FP resonators measured against the hydrogen 1S-2S transition and also using an optical
frequency comb referenced to a hydrogen maser.
When ULE FP cavity temperature is stabilized around the zero thermal expansion point
the FP resonance frequency drift is very small and it is dominated by the aging of the
cavity. Our 77.5 mm long ULE FP resonator that is stabilized at the zero expansion
temperature [1, 2] has a temperature sensitivity of ca 20 Hz/mK and during 2 weeks of
measurements we could clearly observe a linear drift of +60(5) mHz/s (5 kHz/day) at 972
nm due to FP aging while measuring an optical beat note with a stable optical frequency
comb. During two 15 h long measurement runs the deviation from a linear drift slope was
within 20 Hz (using 100 s counter gate time). It was also observed that, unfortunately,
the drift rate slightly changed from day to day.
Our second 972 nm ULE FP cavity (length 77.5 mm) that is stabilized 20K above the
optimal zero expansion temperature is having temperature stability of 11 kHz/mK and
exhibits frequency uctuations in 20 kHz range per day that we attribute to the stability
of the temperature control. When the temperature controller is activated it takes
approximately 2 weeks for this ULE FP cavity resonance frequency to stabilize.
The resonance frequency of our oldest ULE FP resonator (length 15 cm) built in 2004 for
dye laser stabilization at 486 nm has been tracked against the hydrogen 1S-2S transition
for 4 years now. It was observed that during the rst year the drift was +80 mHz/s
and at present it has decreased to +40 mHz/s at 486 nm. This can be explained by the
relaxation of the cavity after mechanical machining. Positive frequency drifts indicate
shrinking of the FP length.
References
[1] J. Alnis, A. Matveev, N. Kolachevsky, Th. Udem, and T.W. Hansch, Sub-Hz line
width diode lasers by stabilization to vibrationally and thermally compensated ultra low
expansion glass Fabry-Perot cavities, Phys. Rev. A, to appear 2008. arxiv:0801.4199.
[2] J. Alnis, A. Matveev, N. Kolachevsky, T. Wilken, R. Holzwarth, T.W. Hansch, Stable
diode lasers for hydrogen precision spectroscopy, Eur. Phys. J. D. Special Topics, to
appear 2008.
CP 74
96
Application of Surface-Enhanced-Raman-Scattering
(SERS) for In-Situ Detection of PAHs in Sea-Water
Heinar Schmidt, Heinz-Detlef Kronfeldt
Institut für Optik und Atomare Physik, Technische Universität Berlin
Hardenbergstr. 36, 10623 Berlin, heinar@physik.tu-berlin.de
Enforced monitoring of sea-water requires advanced instrumentation and technologies for
long term and unattended observation. In particular real time and in-situ sensors are of
interest. In this field, sensors tragetting organic pollution are scarce.
We present a sensor based on surface-enhanced Raman scattering (SERS) using disposable
SERS substrates as sensing membrane which have been designed for the in-situ detection
of polynuclear aromatic hydrocarbons (PAHs). Raman spectroscopy was chosen due to
the fingerprinting nature of the spectra useful for the identification of organic substances
and SERS was applied to achieve the sensitivity for trace detection in the environment.
The SERS sensor was developed as part of the EU-funded projects SOFIE („Spectroscopy
Using Optical Fibres in the Marine Environment“) and MISPEC („Multiparametric insitu
Spectroscopic Measuring Platform for Coastal Monitoring“) where a field-operable
device was constructed, characterised and field-tested in the Baltic Sea, at the Atlantic
coast and in the Bosphorus. The underwater system consists (amongst other) of a robust
SERS optode which is coupled to a core instrument containing a 785nm diode laser and
an axial spectrograph with TE-cooled CCD detector.
We present results of laboratory tests characterising the SERS substrates in terms of
selectivity, adsorption kinetics, adsorption from mixtures of up to eight PAHs and limits of
detection for selected PAHs. The influence of salinity, flow conditions and high immunity
against turbidity are shown. In-situ SERS and Raman spectra from the sea trials will
be presented. The potential and limitations of Raman and SERS spectroscopy will be
discussed with a view to marine in-situ applications.
CP 75
97
Laser Based Isotopic Separation of Atoms
Shahzada Qamar Hussain1, M. Saleem2, Dr. M. Aslam Baig
1Quaid-i-Azam University, Department of Physics, Islamabad
2COMSATS Institute of Information Technology, Department of Physics, Defence Road
O Raiwind Road, Lahore, Pakistan
A design and fabrication of an atomic beam system is presented. The beam source consists
of a cylindrical oven made of stainless steel enclosed by a cylindrical heater for producing
the vapor of the sample in the oven [1,2]. The atomic beam source is simple, versatile
and can be operated at stable temperatures up to 1000K. The atomic beam apparatus is
placed inside the locally developed Time of Flight (TOF) mass spectrometer. Interaction
of laser with the atomic beam in the interaction region of the TOF mass spectrometer
produces ions that are resolved and detected by the TOF mass spectrometer. The ob-
served signals from the TOF mass spectrometer are correlated with the ight times for
di erent isotopic masses. The optimum performance of the atomic beam-TOF mass spec-
trometer is checked with the isotope separation of lithium and magnesium. Their relative
abundance is found very close to the already cited values in the literature.
The locally designed and fabricated atomic beam-TOF mass spectrometer is therefore
capable for the spectroscopic studies of the selected isotopes of elements. The apparatus
can be utilized for Laser isotopic separation of light elements possessing su cient vapor
density up to 1000K.
References:
[1] "High temperature metal atomic beam sources", K.J. Ross and B. Sonntag, Rev. Sci.
Instrum. 66(9), 4409 (1995).
[2] "High Temperature Materials and Technology", E. Compbell and E. M. Shewood,
Wiley, New York, (1967).
CP 76
98
Atomic °uorescence coupled into a thin optical ¯bre
D. Gleeson1;2, V. Minogin2;3;4 and S. Nic Chormaic1;2
1 Physics Department, University College Cork, Cork, Ireland
2Photonics Centre, Tyndall National Institute, Prospect Row, Cork, Ireland
3Dept. of Applied Physics and Instrumentation, Cork Institute of Technology,
Bishopstown, Cork, Ireland
4 Institute of Spectroscopy, Russ. Ac. of Sciences, 142190 Troitsk, Moscow Region,
Russia
E-mail: danny.gleeson@tyndall.ie
In recent years there has been considerable interest in the problem of the interaction be-
tween optically excited atoms and dielectric nanobodies. The basic aspects of such an
interaction are the modi¯cation of the spontaneous emission rate near nanobodies [1-3]
and the dependence of the coupling of atomic °uorescence to the nanobody on the strength
of the interaction between the atoms and the surface of the nanobody. These studies are
important for developing new spectroscopic techniques to measure interactions between
atoms and nanobodies as well as developing new experimental schemes to control internal
and translational atomic states near optical nanobodies [4, 5].
Here, we report on the spectrum of °uorescence emitted by optically excited atoms into
the fundamental guided mode of an optical nano¯bre. An ensemble of two level atoms
in the vicinity of a nano¯bre is considered. The atoms are excited by a laser ¯eld near-
resonant to the atomic dipole transition and emit °uorescent light. The frequency of the
°uorescent light is chosen to be below the cut-o® frequency of all guided modes bar the
fundamental, and so only this mode is generated by the °uorescent light.
We ¯nd that when an atom is far from the surface of the ¯bre it is most e®ectively excited
by the laser ¯eld with a frequency close to the atomic transition for the free atom. When
the atom is close to the surface of the ¯bre, we see that it is now excited at a red-shifted
frequency. This shift leads to an asymmetry of the °uorescence line, observed as the
power of light coupled into the nano¯bre. This selectivity can be used for measuring the
strength of the interactions, including the evaluation of the van der Waals constant. It
can also be used for the control of the atomic states near optical nano¯bers. We evaluate
the atomic °uorescence spectrum for 133Cs atoms excited at the 6S-6P optical transition
with wavelength 852 nm.
References
[1] T. Sondergaard and B. Tromborg, Phys. Rev. A 64, 033812 (2001)
[2] V. V. Klimov and M. Ducloy, Phys. Rev. A 69, 013812 (2004)
[3] Fam Le Kien, S. Dutta Gupta, V. I. Balykin, and K. Hakuta, Phys. Rev. A 72, 032509
(2005)
[4] V. I. Balykin, K. Hakuta, Fam Le Kien, J. Q. Liang, and M. Morinaga, Phys. Rev. A
70, 011401 (R) (2004)
[5] K. P. Nayak, P. N. Melentiev, M. Morinaga, Fam Le Kien, V. I. Balykin, and K.
Hakuta, Opt. Express 15, 5431 (2007).
CP 77
99
Nonlinear dynamics of atoms in a cavity:
The role of finite temperature effects
D.U.Matrasulov1, T.A.Ruzmetov1, D.M.Otajanov1, P.K.Khabibullaev1,
A.A.Saidov1 and F.C.Khanna2
1Heat Physics Department of the Uzbek Academy of Sciences,
28 Katartal Sreet, 100135 Tashkent, Uzbekistan
2Physics Department of the University of Alberta,
Edmonton, Alberta, T6G 2J1 Canada
E-mail: davrano@yahoo.com
Cavity quantum electrodynamics is an area of physics studying the interaction of
atoms with photons in high-finesse cavities in a wide range of the electromagnetic spectrum
from microwaves to visible light. The fact that the system “atom + cavity mode” is a quantum
system makes cavity quantum electrodynamics (QED) an excellent testing ground for such
important issues of modern quantum physics as quantum measurement theory, entanglement,
quantum computation, quantum interference and at the same time provides a unique
possibility for trapping, cooling and manipulating of atoms. Practical importance of cavity
QED is mainly related to potential possibility for manipulating atoms and photons in
mesoscopic scales. Therefore, in recent years cavity QED has become one of the hot topics
both in theoretical and experimental physics [1- 3].
Since the dynamics of a single atom trapped in a microcavity is governed by quantum
electrodynamics, the cavity QED can be considered as an interdisciplinary area. Many
subfield of physics, such as quantum and atomic optics, cold atom physics, physics of
nanosized systems and quantum information, may use important results of the cavity QED.
Recently cavity QED is considered in the context of nonlinear dynamics [3]. Mapping
quantum equations of motion onto classical ones, for the Jaynes-Cummings Hamiltonian,
which includes recoil motion of the atom, Prants et. al., explored phase-space dynamics of the
atom interacting with a single cavity mode by analyzing Poincare surface sections and
calculating Lyapunov exponents [3].
In this work we explore finite-temperature nonlinear dynamics of an atom coupled to a
single mode of the cavity field. Applying the formalism of a real-time finite-temperature field
theory to the Jaynes-Cummings Hamiltonian and using the same approach as that used in we
have studied classical dynamics of the “atom + cavity mode” system in the presence of
coupling to a thermal bath.
Using the temperature-dependence of the equations of motion, dependence of the
dynamics on heat-bath effects or finite temperature effects are considered. The results show
that the dynamics is quite sensitive to the small changes of temperature. This implies that
temperature of a thermal bath can be considered as an additional control parameter for the
dynamics of an atom coupling to cavity modes.
References
[1] Cavity Quantum Electrodynamics. Edited by P.R.Berman, (Academic, New York 1994).
[2] Special Issue on Modern Studies of Basic Quantum Concepts. Phys. Scr., T76 (1998).
[3] S.V.Prants, M.Edelman, G.M.Zaslavsky, Phys. Rev. E., 66 046222 (2002).
CP 78
100
Storage of optical pulses in solids despite fast
relaxation
G.G. Grigoryan1, Y.T. Pashayan-Leroy2, C. Leroy2 and S. Gu´erin2
1Institute for Physical Research, 0203, Ashtarak-2, Armenia
2Institut Carnot de Bourgogne, UMR 5209 CNRS - Universit´e de Bourgogne, BP 47870,
21078 Dijon, France
The solid-state systems are very attractive for optical information storage due to their
high density, compactness, and absence of diffusion. The main drawbacks of solid-state
materials are huge inhomogeneous broadenings. In practice an efficient storage of information
requires a large optical depth [1] such that even negligibly weak losses being
accumulated at such long distance result in an essential loss of information. In order to
reduce the inhomogeneous broadening, it was proposed in a number of works to use the
so-called hole burning technique [2]. However, this technique leads to the reduction of the
optical depth of the samples employed. The natural question is whether it is possible to
store optical information in solids using reduced optical depths.
Analytical studies performed in the limit of short pulses showed that the length of information
storage in - type medium depends remarkably on the ratio between the oscillator
strengths of the adjacent transitions [3]. In the present work by exploiting this property
we propose a novel scheme of short length storage in media featuring fast relaxations.
We perform a complete analytical and numerical study of the full set of the density-matrix
and Maxwell equations for both pulses in case of arbitrary relaxation times and arbitrary
intensities of the probe and control fields in a - type medium. Our detailed analysis
shows that the storage of the probe field in inhomogeneously broadened media is more
efficient when we use atoms of different adjacent transition strengths. In this case the
control pulse should have longer duration but considerably lower intensity than the probe
pulse. The possibility of the retrieval of an intense pulses stored in a medium is also
discussed.
References
[1] M. Fleischauer and M.D. Lukin, Phys. Rev. Lett. 84 , 5094 (2000); I. Novikova, A.V.
Gorshkov, D.F. Phillips, A.S. Sørensen, M.D. Lukin, R.L. Walsworth, Phys. Rev. Lett.
98, 243602 (2007).
[2] M.S. Shahriar, P.R. Hemmer, S. Lloyd, P.S. Bhatia, A.Craig. Phys. Rev. A 66,
032301 (2002); M. Nilsson, L. Rippe, S. Kroll, R. Klieber, D. Sutter, Phys. Rev. B 70,
214116 (2004).
[3] G.G. Grigoryan and Y.T. Pashayan. Phys. Rev. A 64, 013816 (2001); G.G. Grigoryan
and G.V. Nikoghosyan. Phys. Rev. A 72, 043814 (2005).
CP 79
101
Purcell-enhanced Rayleigh scattering into a
Fabry-Perot cavity
Michael Motsch, Martin Zeppenfeld, Gerhard Rempe, and Pepijn W.H. Pinkse
Max-Planck-Institut fÄur Quantenoptik, Hans-Kopfermann-Str. 1, 85748 Garching,
Germany
In recent years a growing interest in cold molecules from ¯elds as di®erent as cold chem-
istry, precision spectroscopy and quantum information science could be observed. Velocity
¯ltering by means of an electrostatic quadrupole guide is an e±cient technique to produce
slow beams of polar molecules from a thermal reservoir. For formaldehyde, ammonia, and
other naturally occurring polar molecules, °uxes of the order of 1010 s¡1 with velocities
down to »10 m/s with only a handful of occupied rotational states have been demon-
strated [1,2]. However, so far no universal method was found to bridge the gap from the
cold (»1 K) to the ultracold (·1mK) regime.
Standard laser cooling schemes fail for molecules due to their complex internal level struc-
ture, and hence lack of a closed cycling transition. By replacing spontaneous emission
with coherent scattering into an optical cavity, the need for a closed transition can be cir-
cumvented [3]. To avoid excitation of the molecular system, operating in the far-detuned
Rayleigh scattering regime is advantageous. Since Rayleigh scattering cross sections are
small compared to typical resonant cross sections and because typical densities of cold
molecular samples are limited, it is unclear if enough light can be scattered into the cavity
to be detected. To achieve e®ective cooling, the power of the coherently scattered light
must be signi¯cantly higher than for detection only.
We have set up a precursor experiment using room-temperature molecules to study the
feasibility of cavity-enhanced detection and cooling of thin samples of cold molecules. As
a ¯rst step in this direction, we plan to experimentally demonstrate that also in the far-
detuned Rayleigh scattering regime an optical cavity can enhance the scattered power.
In our experiment we use a high-power single-frequency cw-laser operating at 532nm as
a transverse pump beam for Rayleigh scattering into the optical cavity. By changing the
cavity ¯nesse, the enhancement of the light scattered into the cavity mode compared to
the free-space situation is shown. We study the polarization, pressure and pump power
dependence of the Rayleigh scattered light into a single mode of the optical cavity and
derive limits for a detectable density of cold polar molecules with the present setup.
References
[1] T. Junglen, T. Rieger, S.A. Rangwala, P.W.H. Pinkse, and G. Rempe, Eur. Phys. J.
D 31, 365 (2003).
[2] M. Motsch, M. Schenk, L.D. van Buuren, M. Zeppenfeld, P.W.H. Pinkse, and G.
Rempe, Phys. Rev. A 76, 061402R (2007).
[3] P. Horak, G. Hechenblaikner, K.M. Gheri, H. Stecher, and H. Ritsch, Phys. Rev.
Lett. 79, 4974 (1997); D. Chan, A.T. Black, and V. Vuleti¶c, Phys. Rev. Lett. 90, 063003
(2003); P. Maunz, T. Puppe, I. Schuster, N. Syassen, P.W.H. Pinkse, and G. Rempe,
Nature 428, 50 (2004).
CP 80
102
Circular and elliptical dichroism effects
in two-photon disintegration of atoms and molecules
M. Ya. Agre
National University of “Kyiv-Mohyla Academy”, 04070, Kyiv, Ukraine
E-mail: magrik@ukr.net
Compact convenient for the analysis expressions for the cross sections considerably simplify
studying the interaction of electromagnetic radiation with atomic systems and allow us to
discover some fine effects. In present paper on the basis of the general symmetry
considerations taking only into account the dipole approximation and without any other
approximations used in atomic calculations we derive the compact invariant expressions for
the angular distribution of photoelectrons escaping from atoms or molecules in the process of
two-photon ionization and for the angular distribution of fragments forming under twophoton
two-particle dissociation of molecules. The dependence on all geometric parameters –
the unit vector p determining the direction of photoelectron (photofragments in the case of
dissociation) motion, k specifying the direction of propagation for the electromagnetic
radiation and the unit complex vector e specifying polarization of the radiation – is
completely separated in the angular distributions in the form of scalar and triple scalar
products of the vectors. The information of the intrinsic structure of the atomic system is
included in few constant dynamic parameters of the system that can independently be
calculated using the well-known approximations.
In case of atoms and optically inactive molecules the angular distributions contain the term
linear in the pseudoscalar degree of circular polarization of the electromagnetic radiation
ξ = ik ⋅ (e × e*) :
ξa Re[k ⋅ (p × e)(p ⋅ e*)] , (1)
where a is a scalar dynamic parameter of the atomic system. The term (1) leads to the
interesting effect of elliptical dichroism in the angular distribution of photoelectrons
(photofragments of the molecule): under elliptical polarization of the radiation, 0<⎟ξ⎟<1, the
density of the particle flux depends on the sign of ξ, i.e., on the clock-anticlockwise rotation
of the field strength of the electromagnetic wave. However, the term (1) does not lead to the
circular dichroism because it vanishes in case of circular polarization of the wave (⎟ξ⎟=1).
The dynamic parameter a in (1) has to change the sign under time reversion. This T-oddness
can appear due to the scattering phase of the escaping particle and due to the resonance level
width in case of the resonant two-photon disintegration of the atomic system.
In two-photon ionization or dissociation of optically active (chiral) molecules the angular
distributions also include the additional terms linear in ξ:
),
5
( 1 2
1 2 b ξk ⋅p + b ξk ⋅ p p ⋅ e − (2)
where b1 and b2 are the pseudoscalar dynamic parameters of the chiral molecule. The terms
(2) do not vanish in case of circular polarization and, therefore, lead to the circular dichroism
in the angular distributions.
The expressions for the angular distributions derived here could also be useful for the
solution of inverse problem finding the atomic dynamic parameters from the experiment.
CP 81
103
Thermal ionization of alkali Rydberg atoms
I. L. Glukhov and V. D. Ovsiannikov
Department of Physics, Voronezh State University, University Square 1, 394006, Russia,
Voronezh
E-mail: GlukhovOfficial@mail.ru
The environmental blackbody radiation (BBR) is a principal factor reducing essentially
lifetimes of Rydberg atoms. Of the three channels of the BBR-induced level broadening
— decay to lower levels, excitation to upper levels and ionization — the latter is the
most destructive one, responsible for the neutral gas breakdown and for supporting the
ionized state of plasmas. Therefore, the rate of the BBR-induced ionization of atoms
from Rydberg states is an important characteristic for describing both the elementary
processes in excited atoms and the kinetics of non-equilibrium gases and plasmas.
We have calculated matrix elements for bound-free transitions in the dipole approximation
for alkali atoms (Li, Na, K, Rb, Cs) on the basis of the Fues’ model potential method [1].
The matrix elements were used for determining the rates of the BBR-induced ionization
from s-, p-, d-states with the principal quantum number n=8–45 at different temperatures.
Our results agree well with the latest available theoretical and experimental data [2,3].
We discovered that the ratio En/kT for the states of maximal ionization rate takes the
values in the range of 0.5–1.3. Therefore, we suggest the relation of an effective principal
quantum number , corresponding to the maximal photoionization rate, with the ambient
temperature T (in Kelvin)
= (350 ÷ 560) T−1/2, where En = −
1
2 2 .
We also generalize our previously reported three-term approximation [4], which was proposed
for helium, to the alkali atoms. Thus, the BBR-induced ionization rate Pn in inverse
seconds is
Pn =
a0 + a1x + a2x2
4[exp(x) − 1]
, where x =
1.579
2T
105 ,
and ai are fitted coefficients, for a given atomic series of states, smoothly dependent on
temperature. This equation provides good results for states in the vicinity of the ionization
rate maximum and for higher energy states. The deviation of results determined by
this approximate equation from those of exact calculations for the states with principal
quantum numbers up to n = 70 does not exceed 15%.
The temperature dependence for a-coefficients is approximated by the relation
ai =
P2
k=0
bikT−k/2,
with nine coefficients bik, fixed for each series, providing rather accurate results in the
ranges of T =100–2000K.
References
[1] N.L. Manakov, V.D. Ovsiannikov, L.P. Rapoport, Phys. Rep. 141, 319–433 (1986)
[2] I.I. Beterov, D.B. Tretyakov, I.I. Ryabtsev, Phys. Rev. A 75 052720 (2007)
[3] I.I. Beterov, I.I. Ryabtsev, D.B. Tretyakov, JETP to be published (2008)
[4] I.L. Glukhov, V.D. Ovsiannikov, Proc. of SPIE 6726, 67261F (2007)
CP 82
104
Hyperpolarizabilities of multiplet Rydberg states in
alkali and alkaline-earth atoms
V.D. Ovsiannikov 1 and E.Yu. Ilinova 1
1 Department of Physics, Voronezh State University, 394006 Voronezh, Russia
The atomic spectra in external ¯elds is one of the most important problems of atomic
Physics and spectroscopy. Sensitive methods were developed for cooling and trapping
atoms, for selective excitation to strictly indicated states, for experimental investigation
of radiative properties of atoms in Rydberg states [1,2]. The spectroscopy of atoms and
atomic ensembles trapped in optical lattices provides new information on the properties of
quantum objects and on elementary processes of radiation-matter interaction. Precision
information on the Stark e®ect in higher orders of perturbation theory is of a special inter-
est in constructing optical frequency standards of a new generation, and also in processing
quantum information on the basis of atomic ensembles in Rydberg states. Therefore, the
development of simple methods for calculating nonlinear atomic susceptibilities, speci¯-
cally those for Rydberg states, seems of primary importance.
Stark shifts of energies for Rydberg SJ ; PJ ;DJ (J=L§S) states of alkali (S=1=2) and
alkaline-earth (S=0; 1) atoms in external electric ¯eld were determined, up to the 4-th
order in the ¯eld strength. To this end, for close sublevels of multiplets, with equal
values of magnetic quantum number MJ , the higher-order perturbation theory for nearly-
degenerate states [3] was used. Analytical equations for energy shifts were presented in
terms of irreducible (scalar and tensor) parts of polarizabilities ®s;t, hyperpolarizabilities
°s;t2;t4 and oscillator strength sums ¯s;t [3]. For irreducible parts of hyperpolarizabilities
and oscillator strength sums the three-term approximation in powers of the e®ective prin-
cipal quantum number º=1=
p
¡2Enl was proposed, which provides accurate estimates to
these values for Rydberg states with arbitrary principal quantum number, up to º = 1000.
The coe±cients of the polynomials were obtained from the corresponding values, calcu-
lated for states with the radial quantum number nr = 25; 26; 27.
Using the calculated data, the "critical" values of ¯eld intensities for double Stark reso-
nance on Rydberg 36P3=2;1=2; 37S1=2; 37P3=2;1=2 states in Na were determined and compared
with experimental and theoretical data of ref.[1]. The account of the 4-th-order terms
amends the agreement with experimental data so, that the di®erence from the results of
ref. [1] does not exceed 1-1.5 percents. Also, for Rb atom, on the basis of our data and
the results previously obtained in [4], the coe±cients were determined, which appear at
F4 in expansion of energy shifts in powers of ¯eld intensity. The data of calculations
demonstrates signi¯cant amendments of agreement between theoretical and experimental
data in comparison with that of the ref. [2].
References
[1] I.I. Ryabtsev, D.B.Tretyakov, JETF 121 787 (2002).
[2] T.Haseyama, K.Kominato, M.Shibata, S.Yamada, T.Saida, T.Nakura, Y.Kishimoto, M.Tada,
I.Ogawa, H.Funahashi, K.Yamamoto, S.Matsuki, Phys.Lett. A 317 450 (2003).
[3] I.L. Bolgova, V.D. Ovsiannikov, V.G. Palchikov, A.I. Magunov, G. von Oppen, JETF 123
1145 (2003).
[4] A.A. Kamenski, V.D. Ovsiannikov, J.Phys B:At. Mol.Opt.Phys. 39 2247 787 (2006).
CP 83
105
Penning ionization of cold Rb Rydberg atoms due to
long-range dipole-dipole interaction
N. N. Bezuglov1;2, K. Miculis1, A. Ekers1, J. Denskat3, C. Giese3, T. Amthor3, and
M. WeidemÄuller3
1 Laser Centre, University of Latvia, LV-1002 Riga, LATVIA
2 Faculty of Physics, St.Petersburg State University, 198904 St. Petersburg, RUSSIA
3 Physikalisches Institut, UniversitÄat Freiburg, D-79104 Freiburg, GERMANY
Ionization in cold collisions of Rydberg atoms is possible via two mechanisms: associative
and Penning ionization. Associative ionization is a short range process of low e±ciency,
because it requires close encounters enabling overlap of Rydberg atom wavefunctions (at
internuclaer distances R ¿ n¤2). In contrast, Penning ionization is a long-range process
(at R À n¤2), which is enabled by the dipole-dipole interaction (atomic units are used in
this abstract)
V =
~D
1~D2 ¡ (~D1~n)(~D2~n)
R3 ; (1)
where ~Di are the dipole moments of both atoms and ~n denotes the orientation of the
internuclear axis.
We consider the formation of atomic ions in an Ager-type processes: one of the Rydbrg
atoms undergoes a dipole transition from the initial state nl to a lower state n0l0, while
the other atom is excited form the initial state nl to the ionization continuum. Such
ionization can take place if the energy released in the nl ! n0l0 transition is equal to (or
larger than) the binding energy of electron in the nl state, which is given by the condition
n¤0
< n¤=
p
2 (n¤ is the e®ective quantum number). Perturbation theory [1] allows one to
express the autoionization width ¡(R) via the photoionization cross section ¾ph of atom
in the nl state and the reduced dipole matrix elements jDnn0 j of the nl ! n0l0 transitions
¡(R) =
e¡
R6 ; e¡ =
X
n0
c¾ph
¼!nn0
jDnn0 j2 (2)
We have evaluated the ionization rates e¡ using semiclassical analytical formulae for both
the photoionization cross sections and the dipole matrix elements derived in [2] for alkali
atoms. The resulting e¡(n¤) is a function that oscillates around the power-law curve
e¡
= Cn¤16=3 with CS = 0:3 and CP = 0:46 for nS and nP states, respectively. These
results should help in understanding the ionization dynamics of cold Rydberg gases [3].
Support by the EU FP6 TOK Project LAMOL, DFG, and ESF is acknowledged.
References
[1] K. Katsuura, J.Chem.Phys., 47, 3770 (1965).
[2] N. N. Bezuglov, V. M. Borodin, . Opt. Spectrosc., 86, 467 (1999).
[3] T. Amthor, M. Reetz-Lamour, C. Giese, and M. WeidemÄuller, Phys. Rev. A 76,
054702 (2007).
CP 84
106
Ionization of alkali-metal Rydberg atoms
by blackbody radiation
I.I.Beterov1, I.I.Ryabtsev1, D.B.Tretyakov1, N.N.Bezuglov2, A.Ekers3, and V.M.Entin1¤
1Institute of Semiconductor Physics, Pr. Lavrentyeva 13, 630090, Novosibirsk, Russia
2Institute of Physics, 198904, St. Petersburg, Russia
3Institute of Atomic Physics and Spectroscopy, LU, LV-1586 Riga, Latvia
E-mail: ¤ventin@isp.nsc.ru
Interaction of Rydberg atoms with blackbody radiation (BBR) was studied for many
years [1]. However, only few works were devoted to BBR-induced ionization of Rydberg
atoms. A renewed interest to this process is related to the recently observed spontaneous
formation of ultracold plasma in dense samples of cold Rydberg atoms and to the prospects
of using the BBR ionization as a convenient reference signal in absolute measurements of
collisional ionization rates.
In this report the results of our extended theoretical calculations of BBR-induced ion-
ization rates of alkali-metal Rydberg atoms are presented [2,3]. Calculations have been
made for nS, nP and nD states of Li, Na, K, Rb and Cs atoms, which are commonly used
in a variety of experiments, at principal quantum numbers n=8-65 and at three ambient
temperatures of 77, 300 and 600 K. A semi-classical model [4] was used to numerically
calculate the bound-bound and bound-free matrix elements. A peculiarity of our calcu-
lations is that we take into account the contributions of BBR-induced redistribution of
population between Rydberg states prior to photoionization and ¯eld ionization by ex-
traction electric ¯eld pulses. The obtained results show that these phenomena a®ect both
the magnitude of total ionization rates and shapes of their dependences on the principal
quantum number n. For Li Rydberg atoms a bound-bound Cooper minimum is observed.
The theoretical ionization rates are compared with the results of our earlier measurements
of BBR-induced ionization rates of Na nS and nD Rydberg states with n=8-20 at 300 K.
A good agreement for all states except nS with n>15 is obtained. The useful analytical
formulas for quick estimates of BBR ionization rates taking into account quantum defects
of Rydberg atoms are also presented. These formulas have been derived using the ana-
lytical formulas for hydrogen matrix elements obtained in [5]. The analytical estimates of
BBR-induced ionization rates well agree with the results of our numerical calculations.
This work was supported by the Russian Academy of Sciences, EU FP6 TOK project
LAMOL, European Social Fund, Latvian Science Council, and NATO grant EAP.RIG.981387.
References
[1] T.F.Gallagher, "Rydberg Atoms", Cambridge University Press, Cambridge (1994).
[2] I.I.Beterov, D.B.Tretyakov, I.I.Ryabtsev, N.N.Bezuglov, and A.Ekers, Phys. Rev. A,
2007, v.75, p.052720.
[3] I.I.Beterov, I.I.Ryabtsev, D.B.Tretyakov, N.N.Bezuglov, and A.Ekers, JETP, 2008 (in
press).
[4] L.G.Dyachkov and P.M.Pankratov, J. Phys. B, 1994, v.27, p.461.
[5] S.P.Goreslavsky, N.B.Delone, and V.P.Krainov, JETP, 1982, v.55, p.246.
CP 85
107
Level-crossing transition between mixed states
B. T. Torosov and N. V. Vitanov
Department of Physics, So¯a University, James Bourchier 5 blvd, 1164 So¯a, Bulgaria
The Landau-Zener model [1] is conventionally used for estimating transition probabilities
in the presence of crossing levels. Nevertheless, because of the in¯nite duration of the
coupling in this model, the propagator involves a divergent phase. It has been shown that
this phase causes unde¯ned populations in the degenerate Landau-Zener model [2].In this
work we show that even in the original Landau-Zener model we have unde¯ned populations
when we deal with pure superposition states or with mixed states. Besides, we show that
the Allen-Eberly model [3] can be used as an alternative to the Landau-Zener model to
describe the dynamics of such level-crossing problems.
References
[1] L. D. Landau, Physik Z. Sowjetunion 2, 46 (1932); C. Zener, Proc. R. Soc. Lond. Ser.
A 137, 696 (1932).
[2] G. S. Vasilev, S. S. Ivanov and N. V. Vitanov, Phys. Rev. A 75, 013417 (2007).
[3] L. Allen and J. H. Eberly, Optical Resonance and Two-Level Atoms (Dover, New York,
1987).
CP 86
108
M1-E2 interference in the Zeeman spectra of Bi I
S. Werbowy and J. Kwela
Institute of Experimental Physics, University of Gdansk, Wita Stwosza 57, 80-952
Gda´nsk, Poland
Precision in atomic parity nonconservation (PNC) measurements have reached the level
required to provide important tests of the electroweak standard model [1]. Nevertheless,
to extract the electroweak quantity of interest, the ’weak charge’, from the experiment,
atomic structure calculations of comparable precision are necessary. The measurement of
the ratio D = AE2/(AE2+AM1) of the electric-quadrupole (E2) and magnetic-dipol (M1)
transition probabilities in mixed forbidden lines can provide stringent test of theoretical
wave-function calculations; accurate knowledge of this quantity is essential for existing
and future measurements of parity nonconserving optical rotation.
The 6s26p3 ground configuration of bismuth gives rise to five levels 4S3/2, 2P3/2,1/2
and 2D5/2,3/2. We report studies [2] of the interference effect in mixed-type forbidden
lines: 461.5nm (2P1/2 →4S3/2), 647.6nm (2D5/2 →4S3/2) and 875.5nm (2D3/2 →4S3/2) of
Bi I. In the past, the mixed M1+E2 type lines 647.6nm and 875.5nm in bismuth were
intensely exploited in PNC experiments [3, 4]. In the Zeeman effect of mixed multipole
lines, the intensities of patterns are not a simple sum of two contributions for M1 and E2
radiations taken in proportion to their transition probabilities, but should be modified by
an interference term. The spontaneous transition probability for a single photon emission
in the presence of the magnetic field can be expressed, according to
aab = (1 − D)aM1
ab + DaE2
ab
± 2 D(1 − D)aM1−E2
ab , (1)
where D is percentage admixture of E2 radiation, aM1
ab and aE2
ab are pure magnetic-dipol
and electric-quadrupole components, respectively, and the cross term aM1−E2
ab describes
the interference effect. The interference effect in emission spectra causes the difference
between the intensities of ΔM=±1 Zeeman patterns observed in longitudinal and transverse
directions of observation. This phenomenon, in a series of experiments, was used
for precise determination of the electric-quadrupole admixture D in forbidden lines.
A special computer program considering the M1-E2 interference was design to obtain
the predicted contour of the Zeeman structure of the line. By variation of free parameters,
describing the line shape and electric-quadrupole admixtures, the calculated profiles were
fitted into the experimental spectra recorded by CCD detector. The E2 admixtures found
are: (7.84±0.14)%, (17.5±0.4)% and (0.70±0.11)% for 461.5nm, 647.6nm and 875.5nm
lines, respectively. Our results were compared with recent theories and other experiments.
This work was supported by grant BW/5200-5-0482-8 and BW/5200-5-0053-8.
[1] C. S. Wood, at. al., Science 275, 1759 (1997)
[2] S. Werbowy and J. Kwela, Phys. Rev. A 77, 023410 (2008)
[3] P. E. G. Baird, at. al., Phys. Rev. Lett. 39, 798 (1977)
[4] J. H. Hollister, at. al., Phys. Rev. Lett. 46, 643 (1981)
CP 87
109
Numerical investigation of NeI for 2p55g configuration
and ArI for 3p55g configuration Zeeman structure
Anisimova G.P.1, Efremova E.A.1, Semenov R.I.1, Tsygankova G.A.1
1St.-Petersburg State University
Petergof, Ulianovskaja st., 1, NIIF-SPbSU, St.-Petersburg, 198504, Russia.
E-mail: efremovakat@inbox.ru
The behavior of an atom in the magnetic field can be studied numerically based on the
parameters of the fine structure (the radial integrals in the energy operator matrix). A
set of the fine structure parameters ensuring the correlation with experimentally observed
energies [1; 2] was obtained in the previous works of the authors.
The authors provide the results of the numerical study of magnetic sublevels behavior for
NeI and ArI (of specified configurations) in the magnetic fields up to 150 kOe.
Using the free momentums representation and the Clebsch-Gordan coefficients the authors
succeeded to obtain the expressions for the diagonal and non-diagonal elements of the
atom-field interaction matrices in LSJM-representation as well as to refine the signs of
the non-diagonal elements.
h ijWj ii =

J(J + 1) + L(L + 1) 􀀀 S(S + 1)
2J(J + 1) gl + J(J + 1) 􀀀 L(L + 1) + S(S + 1)
2J(J + 1) gs

0HM
( J = L = S = 0)
h ijWj 0 ji =
s
(J 􀀀 L + S + 1)(J + L 􀀀 S + 1)(J + L + S + 2)(L + S 􀀀 J)
4(J + 1)2(2J + 1)(2J + 3)
((J + 1)2 􀀀M2)
(gl 􀀀 gs) 0H
( J = 1, L = S = 0, Jmin)
The energies of Zeeman’s sublevels were calculated by means of the diagonalization of
the complete energy operator matrix, which was expressed in LS-representation with
additional elements accounting for the atom-field interaction. The diagonalization was
carried out for all the values of the magnetic quantum number M.
The distinctive details of Zeemann’s structure especially points of crossing and anticrossing
areas of magnetic sublevels were obtained for 2p55g configuration of NeI and 3p55g
configuration of ArI.
References
[1] Chang E.S., Schoenfeed W.G., Biemont E., Quinet P., Palmeri P., Phys. Scr. V. 49.,
26-33 (1994)
[2] Palmeri P., Biemont E., Phys. Scr. 1995. V. 51., 76-80 (1995)
CP 88
110
Method for quantitative study of atomic transitions
in magnetic ¯eld based on vapor nanocell with L =¸
A. Papoyan1,G. Hakhumyan1;2, A. Atvars3, M. Auzinsh3 and D. Sarkisyan1.
1 Institute for Physical Research, NAS of Armenia, Ashtarak-0203, Armenia
2 Russian-Armenian State University, 123 Hovsep Emin str., Yerevan, 0051 Armenia
3 Department of Physics, University of Latvia, 19 Rainis blvd., Riga, LV-1586 Latvia
E-mail: papoyan@ipr.sci.am
It is well known that atoms placed in an external magnetic ¯eld undergo shift of their
energy levels and change in their transition probabilities. To study these changes, widely
used saturation absorption technique has been used in [1]. However, the complexity of
Zeeman spectra in magnetic ¯eld arises primarily from the presence of strong crossover
resonances, which are also split into many components strictly limiting the range of study
to 5 ¥ 50 G, while the most signi¯cant changes are expected for B » 1000 G.
A method, which we call " L =¸ Zeeman technique" (¸ -ZT) has been implemented for
investigation of the individual transition between the Zeeman sublevels of the hf structure
of alkali atoms in magnetic ¯eld 1 ¥ 2500 G. The ¸-ZT is based on the employment of
a nanocell with the thickness of Rb vapor column equal to the wavelength of diode laser
radiation resonant with D2 line of atomic 85Rb, 87Rb (¸ = 780 nm). At the laser intensity
1 mW/cm2, narrow ( » 10 MHz) resonant velocity selective optical pumping/saturation
(VSOP) peaks of reduced absorption appear in the transmission spectrum localized ex-
actly at the atomic transitions [2]. These VSOP peaks are split to separate components
in magnetic ¯eld; the amplitudes (which are proportional to transition probability) and
frequency positions of the components depend on B - ¯eld.
Particularly, it is revealed that in relatively weak magnetic ¯eld (» 100 G) with ¾+-
polarized laser radiation also those atomic transitions are recorded, for which new selec-
tion rules with respect to the quantum number F take place: 87Rb D2, Fg=1, mF= 1
Fe=3, mF=0 transition (let call it (2)) increases with the increase of the magnetic ¯eld,
and at B » 200 G becomes equal to probability of the strongest transition Fg=1, mF=+1
Fe=2, mF=+2 (let call it (1)) for B = 0. At higher magnetic ¯eld up to 2000 G probabil-
ity of the atomic transition (2) is the largest, while for B > 2000 G again the probability
of (1) is larger than that of (2). Note that implementation of ¸-ZT technique is very
convenient to study atomic transitions behavior also at higher magnetic ¯eld > 2000 G.
Particularly, by measuring the frequency di®erence between transition (1) and transition
(2) it is possible to measure a strongly non-homogeneous magnetic ¯eld of 150 G/mm.
This is achieved by displacement of the nanocell by 10 - 20 ¹m in the direction of magnetic
¯eld gradient. The theoretical model very well describes the experimental results.
Also, the performed studies showed that the atomic transition Fg=1 ! Fe=2 of 87Rb D1
line (¸ = 794 nm) is very convenient for determination of uniform, as well as strongly
non-uniform magnetic ¯eld strength in the range of 5 ¥ 10 000 G.
References
[1] M.U. Momeen, G. Rangarajan, P.C. Deshmukh, Journ. Phys. B: At. Mol.Opt. Phys.
40, 3163 (2007).
[2] C. Andreeva, S. Cartaleva, L. Petrov, S.M. Saltiel, D. Sarkisyan, T. Varzhapetyan, D.
Bloch, M. Ducloy, Phys. Rev. A 76, 013837 (2007).
CP 89
111
g factor of boronlike ions
D. A. Glazov1, A. V. Volotka2, V. M. Shabaev1, I. I. Tupitsyn1 and G. Plunien2
1 Department of Physics, St. Petersburg State University, Oulianovskaya 1,
Petrodvorets, St. Petersburg 198504, Russia
2 Institut fur Theoretische Physik, TU Dresden, Mommsenstra e 13, D-01062 Dresden,
Germany
E-mail: glazov@pcqnt1.phys.spbu.ru
High-precision measurements of the g factor of H-like carbon and oxygen, performed by
the GSI - Universitat Mainz collaboration, combined with the corresponding theoretical
investigations, have provided a new determination of the electron mass to an accuracy that
is four times better than that of the previously accepted value. An extention of the g factor
experiments to higher-Z systems is anticipated in the near future at the HITRAP facility
at GSI (Darmstadt). As was demonstrated in [1], investigations of a speci c di erence
of the g factors of H- and B-like ions can provide an independent determination of the
ne structure constant to an accuracy comparable to that of the recent determination by
Gabrielse et al. [2].
We perform accurate calculations of the ground-state g factor of B-like ions in a wide range
of nuclear charge numbers. The calculational methods were already employed in [3,4] for
Li-like ions. One-loop QED corrections were evaluated in e ective screening potential. To
our best knowledge, this is the rst correct evaluation of the QED correction to the g factor
of the 2p state. The one-photon exchange correction was calculated in the framework of
QED. The large-scale con guration-interaction Dirac-Fock-Sturm method was employed
to take into account the electron-correlation e ects of the order 1=Z2 and higher. As a
result, the most accurate up-to-date values of the g factor of B-like ions are obtained.
References
[1] V. M. Shabaev et al., Phys. Rev. Lett. 96 (2006) 253002.
[2] G. Gabrielse et al., Phys. Rev. Lett. 100 (2008) 120801.
[3] D. A. Glazov et al., Phys. Rev. A 70 (2004) 062104.
[4] D. A. Glazov et al., Phys. Lett. A 357 (2006) 330.
CP 90
112
Magnetoelectric Jones spectroscopy
of Li and Na atoms
V.V.Chernushkin, V.D.Ovsiannikov
Theoretical Physics Dept, Voronezh State University, Voronezh, Russia,
E-mail:albert@phys.vsu.ru
Magnetoelectric birefringence, which was predicted by Jones1 and ¯rst observed in liq-
uids2, may also become a useful tool for high-precision laser spectroscopy of atomic sys-
tems3.
The amplitude of the Rayleigh scattering of a monochromatic wave with the frequency
! = EnDJ ¡ EnS1=2 ¡ "J in resonance (j"J j ¿ !) with the D-level doublet substates of
the total momentum J = 3=2; 5=2, may be written as (taking into account only the terms
with the second-order resonance singularities)
U = AQ
Ã
7
("3=2)2 +
47
("5=2)2
¡
4
"3=2"5=2
!
['0 + '1]; (1)
where the constant factor A = F2F0B=1500 is proportional to the product of the square
laser ¯eld F2, static electric ¯eld F0 and magnetic ¯eld B. The polarization-dependent
factors are
'0 = (e0 ¢ [n £ eB]) ; '1 = Ref(e0 ¢ e) (e¤ ¢ [n £ eB])g;
where eB and e0 are unit vectors of magnetic and electric ¯elds, e and n are unit po-
larization and wave vectors of the laser wave. The complex quantities "J = ¢J ¡ i¡J=2
include both the resonance detuning ¢J for the real part and the resonance level width ¡J
for the imaginary part. The factor QD is a product of the radial matrix elements for the
¯rst-order quadrupole and second-order dipole radiation transition between the ground
nS1=2 and resonance n0D states (the in°uence of the ¯ne structure on radial integrals is
neglected):
QD = hnSjr2jn0DJ2ihn0DJ1 jr(g!
P + g0
P )rjnSi;
The Jones birefringence appears, when e0 = eB, due to the di®erence between the ampli-
tude (1) for e = e(+) and e = e(¡), where e(§) = (e0 § [n £ e0])=
p
2:
¢U(J)
D = U(+)
D ¡ U(¡)
D = 2AQD
Ã
7
("3=2)2 +
47
("5=2)2
¡
4
"3=2"5=2
!
:
Similar e®ects in atoms with singlet structure of levels, which correspond to "3=2 = "5=2,
were discussed in4.
1R. C. Jones, J. Opt. Soc. Am. 38, 671 (1948).
2T. Roth and G. L. J. A. Rikken, Phys. Rev. Lett. 85, 4478 (2000).
3D. Budker and J. E. Stalnaker, Phys. Rev. Lett. 91, 263901 (2003).
4P. V. Mironova, V. V. Tchernouchkine, V. D. Ovsiannikov, J. Phys. B, 39, 4999 (2006).
CP 91
113
Radiative transition probabilities from D Stark states
in orthohelium
A. A. Kamenski1 and V. D. Ovsiannikov1
1Department of Physics, Voronezh State University, 394006, Voronezh, Russia
The dependence of radiative line intensity on external ¯eld strength is an important
characteristic of radiative properties, which gives rise to new lines in the emission and
adsorption spectra and in su±ciently strong ¯elds removes a number of lines that exist
in the spectrum of a free atom. Our calculations for the pair-wise interacting sublevels
were based on the integral SchrÄodinger equation for close levels [1]. The total momenta
projection M determines a group of multiplet sublevels interacting with one another in
the lowest order of external DC electric ¯eld. Even for a general case of arbitrary angular
L and spin S momenta, one can ¯nd the states interacting in pairs. General analysis of
di®erent pairwise interacting substates with equal parity demonstrates common features of
the ¯eld-dependent probability behaviour. In particular, we discovered the equalization of
probabilities in the anticrossing ¯eld and vanishing of one of the two doublet components
in a strong-¯eld limit [1].
In this communication we present some results on the radiative transitions from triple-
interacting sublevels of atoms in a DC electric ¯eld. The perturbation operator matrix
takes into account the interaction of an atom with a dc ¯eld in all orders of the ¯eld
amplitude. The atomic wavefunction in the ¯eld is reduced to a set of homogeneous
algebraic equations for the superposition coe±cients [1,2].
The simplest example of triple-interacting sublevels are D-states of orthohelium atom
with M = §1. We calculate numericaly energy shift and wave function superposition
coe±cients for this case in the ¯rst nonvanishing order of perturbation theory. As for the
pair-wise interacting levels, the sign of the tensor polarizability determines the behaviour
of triplet states in the ¯eld. So the sublevels approaching each other in orthohelium
atom, as ¯eld strength increases, occurs only in 3D-state with positive tensor part of
polarizability ®t
3D>0, and does not appear for nD-states with n ¸ 4 where ®t
nD<0 [2].
In order to reveal the impact of the anticrossing e®ect explicitly, we consider the ¯eld
dependence of the probability of radiative transition from the triple-interacting n 3D-levels
to an isolated n0 3PJ-sublevel (with J = 1;M = 0 or J = 2;M = §2) or to n0 3F3-sublevel
with M = 0. Such transitions give triplet structure of corresponding radiative lines.
The vanishing of some ¯ne-structure components with the growth of the ¯eld strength
corresponds to our asimptotic results for orthohelium lines [1].
Such dependence is not monotonous, and we discovered zero-intensity points and intensity
maximum among the ¯ne-structure P ¡ D-lines. This e®ect can be useful for selective
control by a dc ¯eld of the radiation processes.
References
[1] A.A. Kamenski, and V.D. Ovsiannikov, Journal of Experimental and Theoretical
Physics, 100, No 3, pp.487-504 (2005)
[2] A. A. Kamenski and V. D. Ovsiannikov, J. Phys. B: At. Mol. Opt. Phys. 39,
2247-2265 (2006)
CP 92
114
Light-induced quasi-static polarization in
hydrogen-like atom under the action of strong
electromagnetic laser field
M.V.Ryabinina, L.A.Melnikov
Saratov State Univerisity, Physics Department
83 Astrakhanskaya, 410012, Saratov, Russia
mvr@vtt.net
For two-level system is well known that the transitions rate parameter is Rabi-frequency.
At large intensities the Rabi frequency can be comparable with an optical transition
frequency ν, while laser electric field remains smaller than intra-atomic field. In this case
temporal variation of probability amplitudes a(t) and b(t) for the levels of two-level system
can occurs at frequencies comparable with nν, n = 1, 2, . . .. As a result, simple analytical
solution is not possible and use of numerical methods [1] is required even for two-level
system.
In present paper the transitions in hydrogen atom induced by the linearly polarized pulse
with a polarization along the axis z are investigated. For hydrogen atom all matrix
elements of transitions are in an analytical form as well as wave functions of discrete and
continuum spectra. The dynamics of populations of 4s and 3p states and polarization
of the transition 4s ↔ 3p are investigated theoretically and numerically at one- , twoand
three-photon resonance conditions and at large detuning out of frame of perturbation
theory and rotating wave approximation.
It was shown that at resonance the low frequency modulation of optical oscillations exists,
producing corresponding quasi-static polarization of atoms along z-axis. The oscillations
frequency becomes zero at the values of laser field amplitude corresponding to ratio of Rabi
frequency to optical frequency ℘E0/ν = 1.05, 2.75, 4.3, 5.8, 7.5, 9, . . . These low-frequency
oscillations are attributed to the special displacement of quasi-energy levels. We have
used the Floquet-type solution of the equations for probability amplitudes:
i ˙a = ℘abb(t)E0(t) cos (νt) exp(iνt), i˙b = ℘aba(t)E0(t) cos (νt) exp(−iνt). (1)
a(t) = exp(iλt)
∞

n=−∞
an exp (iνnt), b(t) = exp(iλt)
∞

n=−∞
bn exp (iνnt).
(iλ + iνn)an = −i
℘abE0(t)
2
(bn + bn−2), (iλ − iνn)bn = −i
℘abE0(t)
2
(an + an+2). (2)
Calculations of the values of λ gives λ = 1
2 for mentioned values of field. In this
case the quasi-levels are crossed. For two-photon transitions λ = 0(nν) for ℘E0/ν ≈
2.4, 4.1, 5.7, . . . demonstrating the same behavior of the polarization.
This effect can be used for measuring the ultra-high intensity pulse amplitudes. The
influence of the transitions to continuum calculated using method of Ref.2 is discussed
also.
References
[1] Bordyug N.V. and Krainov V.P. Laser Phys. Lett. v.4, 418(2007)
[2] Ryabinina M.V., Melnikov L.A. AIP Conference Proc. v.796, 325(2005)
CP 93
115
Doppler-free spectroscopy of rubidium atoms placed
in a magnetic field
G. Skolnik, N. Vujicic, T. Ban, S. Vdovic and G. Pichler
Institute of Physics, Bijenicka 46, Zagreb, Croatia
Saturation spectroscopy (SAS) is one type of high resolution laser spectroscopy and is
widely used in alkali atomic vapour system for observing the sub-Doppler resonances [1].
In SAS technique two counter-propagating laser beams, which derive from the single laser
source, simultaneously interact with zero velocity group of atoms. The pump laser beam
burns a hole in the Boltzmann distribution curve of the lower level and when the probe
laser beam comes across this hole, in the absorption spectrum a Lamb dip can be observed.
This dip has a Doppler-free Lorentzian line shape depending on the natural, collision and
the transit time broadening and on the laser linewidth.
In this work we used saturation spectroscopy and improved it with an application of a
lock-in technique. This technique eliminates broad Doppler-background from the signal
and enables a resolution of all hyperfine transitions. We investigated the resonance D2
line of rubidium vapour by External Cavity Diode Laser (ECDL). The observed Dopplerbroadend
profiles consist of four lines, two of them resulting from 85Rb absorption and the
other two from 87Rb. In SAS techique for each absorption line three hyperfine transitions
and three belonging crossovers were obtained. In addition, we performed the theoretical
simulations of the measured Lorentzian profiles. In saturation spectrum of 87Rb an inverse
negative crossover resonance appiered as a consequence of alignment effect and its
dependence on polarization of the laser beams and on the magnetic field strength was
measured.
We measured line shape dependence on the magnetic field strength. Our experimental
arrangement contains of two parts in order to measure magnetic field effect on rubidium
vapour at one part and simultaneously compare it with the other one that has no magnetic
field influence. In this way the first part serves as a reference scale for frequency valuation.
An offset in the central frequency line position, increase in linewidth of each transition
line and decrease in line intensity due to the enhancement of magnetic field strength were
observed. Measured experimental results show good agreement with applied theoretical
model.
Our experimental measurements belong to a group of nonlinear magneto-optic effects
that show their significance in laser spectroscopy, where they are applied in high-precision
magnetometry, weak transition researches such as magnetic dipole transition with small
magnetic moment, parity violation experiments and nowadays in quantum computing
processing investigations.
[1] W. Demtroeder, Laser Spectroscopy, (Springer-Verlag, Berlin, 2003)
CP 94
116
Electric field influence on the hydrogen atom
embedded in a plasma
Mariusz Pawlak and Mirosław Bylicki
Institute of Physics, Nicolaus Copernicus University
Grudziadzka 5, PL-87-100 Torun, Poland
The energy levels of a hydrogen atom in a uniform strong electric field and embedded
in a plasma are investigated. The plasma environment modifies the potential around the
charged particle. This influence is represented by the Debye screening. Hence the Yukawa
potential is used to represent the plasma-modified electron-nucleus interaction. The effect
of this modification is that [1]: (i) The number of bound states of a given spherical
symmetry (for a given orbital quantum number) is finite. (ii) Their energy levels are
shifted up. (iii) The states whose energies are shifted just above the continuum threshold
become resonances.
An external homogeneous electric field causes further changes: (iv) It breaks down the
spherical symmetry. (v) It shifts the energy of some states down and up of other ones (the
Stark effect). (vi) It also turns all the bound states into quasibound resonances.
We include all these effects in our complex coordinate rotation calculation within a basis
set of square integrable functions. The obtained complex energies give us positions and
widths of the energy levels. They migrate in the complex plane when the field strength
changes. Occasionally they tend to cross. Interesting avoided crossing structures appear.
References
[1] M. Bylicki, A. Stachów, J. Karwowski, P. K. Mukherjee, Chem. Phys. 331, 346 (2007)
CP 95
117
Dynamic and Geometric Phases in the Stark-Zeeman
e ect of the hyper ne structure of one-electron atoms
B. Schnizer, Th.Heubrandtner, E. Rossl, M. Musso
Institut fur Theoretische Physik - Computationl Physics, TU Graz, Austria
Virtual Vehicle Competence Center, Graz, Austria
Philips Research Europe - Hamburg, Germany, Sector Medical Imaging Systems
Fachbereich Materialforschung und Physik, Universitat Salzburg, Austria
A theoretical investigation of the Stark-Zeeman e ect of the np 2P3=2 ne structure levels
of atoms with one radiant electron and a core of closed shells with nuclear spin I = 1
(6Li) or I = 3/2 (7Li, 23Na, 69Ga, 71Ga) predicted crossings and anticrossings. These were
con rmed in an experiment. They could be predicted in the adiabatic approximation from
the structure of the energy surfaces En(B;E) in their dependence on the magnetic eld B
and the electric eld E. Two of these surfaces meet in the crossing points. There are two
types of such crossing points resulting from the quadratic dependence of the Stark e ect
on E. In some crossing points the energy surfaces meet in a bicone, in the other ones
they have an osculating contact in the E-direction. When the electric and magnetic elds
are varied such that the phase point of the atom surrounds a biconical crossing points
then the wave functions of the two levels concerned change sign; on the other hand a path
around a crossing point of the second type does not change the sign. We assume that
the change in sign corresponds to a geometric phase of absolute value . As a rst step
for the feasibility of nding this geometric phase in an experiment, the dynamic phase
connected with such time-dependent eld variations has been investigated. Values of all
these phases will be presented.
CP 96
118
New analytical relativistic formulae for the total
photoe®ect cross section for the K-shell electrons
A. Costescu1, C. Stoica1 S. Spanulescu2
1University of Bucharest
2Hyperion University of Bucharest
We present a new analytical relativistic result for the total photoe®ect cross section for
the K-shell electrons, in the lowest order of perturbation theory. In the cases of low atomic
number values, the well known Sauters formula is recovered as a rough approximation of
the exact relativistic result. For high atomic numbers, due to the speci¯c behavior at
small distances from the nucleus of the ground state Dirac spinor, some subtle relativistic
e®ects are revealed near the photoe®ect threshold. Also, our formulae contain all terms
contributing at high energies in the next order of the perturbation theory, obtaining in
the limit of in¯nite photon energy the correction term due to Pratt and Gavrila. In the
nonrelativistic limit, we get the right result involving all the multipoles and retardation
terms without the spurious singularities presented by Fischer's formula. Numerical eval-
uations of these formulae give very good predictions, within 5% for photon energies up to
5 MeV, comparing with accurate relativistic calculations existing in the literature.
Using the Green function method we obtain the imaginary part of the forward elastic
scattering amplitude which provides via the optical theorem the photoe®ect cross section
and also the pair production cross section with the electron created in the K shell.
Our formalism allows including the screening e®ects which may be important near the
photoe®ect threshold, by using an e®ective nuclear charge Zeff depending on the pho-
ton energy !. Taking into account the screening e®ects, the obtained photoe®ect cross
sections present an even better agreement with the experimental cross sections and other
relativistic calculations in the region near the threshold.
We point out that cross section for the K -shell electrons provides, in the high energy
regime, the most important contribution to the total cross section of the whole atom.
Thus, our formulae are useful for an important range of the gamma spectrum, where
there is a lack of accurate formulae for the photoe®ect cross sections, and may present
interest in various experiments where gamma interactions with intermediate and high Z
targets are involved.
References
[1] Lynn Kissel, R. H. Pratt, and S. C. Roy, Phys. Rev. A 22, 1970 (1980);
[2] J.H. Sco¯eld, Lawrence Radiation Laboratory Report No. CRL 51326, Livermore, CA,
1973 (unpublished)
[3] L. Hostler, R.H. Pratt, Phys. Rev. Lett. 10, 469 (1963);
[4] C.Martin, R. J. Glauber,"Relativistic Theory of Radiation Orbital Electron Capture",
Phys. Rev. 109, 1307 (1958);
[5] J. Schwinger, J. Math. Phys, 5, 1606 (1964);
[6] M. Gavrila, AIP Conf. Proc. No. 94,Eugene, Oregon, 1982.
CP 97
119
Two-photon above-threshold ionization by a
VUV-light
N. L. Manakov, S. I. Marmo and S. A. Sviridov
Department of Physics, Voronezh State University,
Voronezh, 394006, Russia
E-mail: sviridovs@yandex.ru
Recent experiments on two-photon above-threshold ionization (2ATI) of inert gases [1,2]
by a VUV radiation renewed the interest to the perturbative analysis of 2ATI (since in
VUV region the perturbation theory (PT) is valid up to high light intensities). The main
difficulty of such calculations is the summation over the intermediate (after absorption of
the first photon) continuum states of escaping electron. In the present work, we calculate
the cross sections of 2ATI for He and alkali atoms in the single-active electron approximation,
using the Fues model potential (FMP) for description of an active atomic electron. The
known analytical expression for the Sturmian expansion of FMP Green’s function allows
to present the 2ATI amplitude in terms of a single series of hypergeometric functions
of two variables, F2 (Appel functions) [3], that, however, becomes divergent for abovethreshold
frequencies, ¯hω > |E0|, where E0 is the ground state energy. For summation of
this divergent series we use the Pade-approximation (ε-algorithm), similarly to that used
for calculations of 2ATI for the hydrogen atom [4]. We justify the applicability of the ε-
algorithm to our problem by independent calculations of the imaginary part of the 2ATI
amplitude and by analytical calculations of low-frequency asymptotics in the in two-color
2ATI (by two, high-frequency and low-frequency, photons). Our numerical results are in
reasonable agreement with experiments [1,2] and other theoretical results [5,6,7,8].
Supported in part by RFBR Grant 07-02-00574.
Table 1: Total cross-sections, σ (in units of 10−52 cm4s), of two-photon ionization (in
linearly polarized field) of He and comparison with experiments and perturbative and
non-perturbative theoretical results [5,6,7,8].
ω, eV Exp. [5] [6] [6], PT [7] [8] σFMP
15.0 – 11 12 12 – – 13
25.0 1.9 [1] 1.0 – – – – 3.2
27.2 – 1.0 4.5 2.5 2.7 – 2.2
41.8 2.0 [2] – – – – 0.53 0.35
45.0 – 0.12 1.0 0.33 – – 0.26
References
[1] N. Miyamoto, M. Kamei, D. Yoshitomi et al., Phys. Rev. Lett. 93, 083903 (2004).
[2] H. Hasegawa, E.J. Takahashi, Y. Nabekawa et al., Phys. Rev. A 71, 023407 (2005).
[3] N.L. Manakov and V.D. Ovsiannikov, J. Phys. B 10, 569 (1978).
[4] S. Klarsfeld and A. Maquet, J. Phys. B 12, L553 (1979).
[5] L.A.A. Nikolopoulos and P. Lambropoulos, J. Phys. B 34, 545 (2001).
[6] J. Colgan and M.S. Pindzola, Phys. Rev. Lett. 88, 173002 (2002).
[7] D. Proulx and R. Shakeshaft, J. Phys. B 26, L7 (1993).
[8] K.L. Ishikawa, unpublished (cf. Ref. [2]).
CP 98
120
Above-threshold polarizability of alkali-metal and
noble gas atoms
N. L. Manakov, S. I. Marmo and S. A. Sviridov
Department of Physics, Voronezh State University,
Voronezh, 394006, Russia
E-mail: sviridovs@yandex.ru
We investigate the dynamic polarizabilities of atoms of alkali metals and inert gases in the
framework of Fues model potential (FMP) method. Using FMP for the atomic valence
electron provides a simple one-particle method for calculation of atomic photoprocesses
[1]. The convenient Coulomb-like expressions for the optical electron’s wavefunctions and
Green function for FMP enables easy calculations resulting in representations of linear and
nonlinear atomic susceptibilities in terms of series in hypergeometric polynomials. These
series can be easily summed at below-threshold frequency values (negative energies of
intermediate states) that in most cases yields the atomic susceptibilities with a reasonable
degree of accuracy. However, for the above-threshold frequencies (¯hω > |E0|) the standard
use of FMP becomes impossible since it leads to divergent series.
For the calculation of the above-threshold bound–bound transitions of optical atomic
electron we develop in this work a special technique based on decomposition of FMP
Green function g
l
(E; r, r
) into double series over Sturmian functions S
kl [2]:
g
l
(E; r, r
) =
∞

k,k
=0
gl
kk
(E; α) S
kl(2r/α) S
k

l(2r

/α) . (1)
Here S
kl(x) ∼ xλ exp (−x/2)L
2
λ
+1
k
(x), λ = λ(l,E), gl
kk
are expressed in terms of product
of Gauss hypergeometric functions 2F1 , α is the arbitrary parameter. To choose the
value of the parameter α, an algorithm is given [3] which ensures the convergence of the
bound–bound matrix elements. Calculations of the above-threshold polarizabilities are
performed for alkali metals and rare gases [3]. The obtained results agree well with the
other author’s calculations. In particular, the He polarizability in the 27...58 eV frequency
range coincides (within 10% accuracy) with more rigorous many-electron calculation [4]
as well as with experiment [5].
Supported in part by RFBR Grant 07-02-00574.
References
[1] G. Simons, J. Chem. Phys. 55, 756 (1971).
[2] A.A. Krylovetsky, N.L. Manakov, and S.I. Marmo, Zh. Exp. Teor. Phys. 119, 45
(2001) [Sov. Phys. JETP 92, 37 (2001)].
[3] N.L. Manakov, S.I. Marmo, and S.A. Sviridov, Zh. Exp. Teor. Phys. 132, 796 (2007)
[Sov. Phys. JETP 105, 696 (2007)].
[4] W. C. Liu, Phys. Rev. A 56, 4938 (1997).
[5] J. A. R. Samson, Z. X. He, and G. N. Haddad, J. Phys. B 27, 877 (1994).
CP 99
121
Ionization in Intense Superposed XUV + NIR Laser
Fields
V. Richardson1, J. Dardis1, P. Hayden1, P. Hough1, E. T. Kennedy1 and J. T. Costello1,
S. Dsterer2, W. Li2, A. Azima2, H. Redlin2, J. Feldhaus2, D. Cubaynes3, D. Glijer3, M.
Meyer3,
1School of Physical Sciences, National Centre for Plasma Science and Technology,
Dublin City University, Dublin 9, Ireland
2HASYLAB, DESY, Notkestr. 85, D-22607 Hamburg, Germany
3LIXAM/ CNRS, UMR 8624 Centre Universitaire Paris-Sud, Btiment 350, F-91405
Orsay Cedex, France
FLASH (i.e. Free electron LASer in Hamburg) operates on the principle of Self Ampli ed
Spontaneous Emission (SASE) and produces coherent, bright and ultrashort eXtreme-
UV (XUV) pulses [1]. The current phase of the project has been in operation since mid
2005. By synchronizing FLASH with an independent optical laser, so-called 'pump-probe'
experiments become possible [2,3]. These experiments are paving the way for fundamental
studies of dynamical e ects in inner-shell photoionisation and photodissociation, as well as
molecular fragmentation [4]. Apart from pump and probe experiments, it is also possible
to induce and control coherent processes in superposed intense XUV and NIR elds.
One such process is photoelectron sideband generation [5]. In this class of experiment,
photoelectrons are ejected by XUV radiation and simultaneously subjected to the intense
eld of an optical laser with which they can exchange photons. In e ect, they absorb/emit
photons with energy corresponding to h!l i.e. that energy of the optical laser photons [3].
As a consequence the photoelectron spectrum is no longer comprised of a single feature
corresponding to the main photoline but is straddled by additional photoelectron lines
separated by h!l, these are referred to as sidebands. In our experiments at FLASH we
have used the 800 nm output ( h!l = 1.55 eV) from a Ti-Sapphire laser which can provide
pulses of up to a 10 mJ in pulse widths from 120 fs to 4 ps.
We have studied this process at high and low optical laser intensity for a range of atoms,
namely He, Ne, Kr and Xe. In extreme cases we observe a large redistribution of the
ejected electrons from the main photoline to the sidebands, so much so that a pronounced
suppression of the main photoelectron line (corresponding to single XUV photon absorp-
tion) occurs when the XUV and the optical pulses are perfectly superposed.
References
[1] W. Ackermann et al, Nature Photonics 1 336 (2007)
[2]P. Radcli e et al, App Phys Lett, 90, 121109 (2007)
[3]P. Radcli e et al, Nucl. Intr. and Meth. A (2007)
[4]J. T. Costello, J. Phys. Conf. Ser 88, (2007)
[5]T.E. Glover et al., Phys Rev Lett. 76, 2468 (1996)
CP 100
122
Photoionization of excited rare gas atoms
Rg(mp5(m+1)p J=0 { 3) in the
autoionization region
I. D. Petrov1, V. L. Sukhorukov1, and H. Hotop2
1Rostov State University of Transport Communications,
344038 Rostov-on-Don, Russia,
2Department of Physics, University of Kaiserslautern,
D-67653 Kaiserslautern, Germany
E-mail: hotop@physik.uni-kl.de
In the present paper we study theoretically the lineshapes of the even autoionizing Ryd-
berg series mp5
1=2(m+1)`0 `0 = 0; 2; 4, excited from the lowest-lying odd mp5(m+1)p J =
0¡3 states of Ne, Ar, Kr, and Xe atoms in the framework of the con¯guration interaction
Pauli-Fock approach including core polarization (CIPFCP) [1{3]. In our previous work
[4{6] this approximation has successfully been applied for the investigation of the odd
Rydberg resonances excited from the even states in rare gas atoms.
Autoionizing mp5
1=2(m + 1)`0 [K0]J0 Rydberg states, excited from di®erent mp5(m +
1)p [K]J levels, attain di®erent lineshapes, as usually characterized by the pro¯le pa-
rameter q [7]. This dependence on the initial level was ¯rst demonstrated experimentally
for the Ne(ns0; J = 1) resonances , excited from several Ne(3p, J = 1; 2) levels [8]. The
comparison between the computed spectra and experimental data indicates that many-
electron e®ects play an important role for both the resonance parameters and the line-
shapes. Absolute values of the experimental cross sections, available for photoionization
of the mp5(m+ 1)p J = 3 levels of Ne, Ar, and Kr, are somewhat smaller than the com-
puted values. These di®erences ask for new precise measurements, e.g. using cold trapped
metastable Rg(mp5(m + 1)s [3=2]2) atoms, especially in view of the good agreement be-
tween the theoretical and experimental cross sections for near-threshold photoionization
of the mp6(m + 1)p levels in the alkali atoms Na { Cs [2,9,10].
Support of this work by the Deutsche Forschungsgemeinschaft is gratefully acknowledged.
References
[1] I. D. Petrov, V. L. Sukhorukov, and H. Hotop J. Phys. B 32, 973 (1999).
[2] I. D. Petrov et al Eur. Phys. J. D 10, 53 (2000).
[3] I. D. Petrov, V. L. Sukhorukov, and H. Hotop, J. Phys. B 36, 119 (2003).
[4] T. Peters et al J. Phys. B 38, S51 (2005).
[5] I. D. Petrov et al Eur. Phys. J. D 40, 181 (2006).
[6] I. D. Petrov et al J. Phys. B 39, 3159 (2006).
[7] U. Fano and J. W. Cooper, Phys. Rev. 137, A1364 (1965).
[8] J. Ganz, M. Raab, H. Hotop, and J. Geiger, Phys. Rev. Lett. 53, 1547 (1984).
[9] K. Miculis and W. Meyer, J. Phys. B 38, 2097 (2005)
[10] I. D. Petrov, V. L. Sukhorukov, and H. Hotop, J. Phys. B 41, 065205 (11pp) (2008).
CP 101
123
Spin Dependent Exchange Scattering from
Ferromagnetic Materials
S.Y. Yousif Al-Mulla
University of Bor as, College of Engineering, Physics and Mathematics Group,50190
Bor as, Sweden
It is well known that the structure information through the use of Spin Polarised Low
Energy Electron Di raction (SPLEED) is highly sensitive to the interaction potential be-
tween the primary electrons and the electrons of the target, especially to the exchange
interaction. Since the electrons in SPLEED penetrate the surface only a few lattice spac-
ing, it is extremely sensitive to the spin structure of a magnetic surface. The early study
of Feder [1] on Fe(110) provides a strong indication in this direction. The main objective
of this work is to use the insights of our recent work [2,3] to study the spin polarisation of
electron scattering from ferromagnetic materials by using the local density approximations
of the exchange-correlation potential. The di erential cross sections for electron scatter-
ing from atoms with net spin, namely nickel and iron, have been calculated together with
studying the energy/ wave vector dependence of the exchange scattering from surfaces
of nickel and iron in glasses by calculating di erential cross sections and the spin asym-
metry. Comparison of predictions with observed spin dependent scattering intensities in
amorphous magnetic alloys will give insight into surface magnetisation in these systems.
[1] Feder R., Solid State Comm. 31, 821 (1979)
[2] S.Y. Yousif Al-Mulla, J. Phys. B: At. Mol. Opt. Phys. 37, 305 (2004)
[3] S.Y. Yousif Al-Mulla, Eur. Phys. J. D 42, 11 (2007)
CP 102
124
Far-wing collisionnal broadening of the Na(3s-3p)
line by helium
K. Alioua1, M. Bouledroua1, A. Allouche2, and M. Aubert-Fr¶econ2
1Laboratoire de Physique des Rayonnements, Badji Mokhtar University,
B.P. 12, Annaba 23000, Algeria
2LASIM, Claude Bernard University, Lyon 1, France
In this work, we examine theoretically the absorption spectra produced by sodium atoms
immersed in a bath of helium. We present our classical and quantum-mechanical cal-
culations of the photoabsorption spectra of the Na(3s!3p) line perturbed by ground
He(1s2) atoms. We particularly focus our attention on the ab initio computation with
molpro of the ground and excited potential-energy curves, through which the systems
Na(3s)+Na(3s) and Na(3p)+Na(3s) interact, and of the corresponding transition dipole
moments. These potentials and moments are used to analyze the absorption spectra and
their possible satellite structure at various temperatures. The results are compared with
previous theoretical and experimental data [1, 2].
References
[1] C. Zhu, J.F. Babb, and A. Dalgarno, Phys. Rev. A 73, 012506 (2006).
[2] H.-K. Chung, M. Shurgalin, and J.F. Babb, AIP Conference Proceedings 645, 211
(2002).
CP 103
125
Excited and ground potassium monatoms perturbed
by helium
S. Chelli and M. Bouledroua
Laboratoire de Physique des Rayonnements, Badji Mokhtar University,
B.P. 12, Annaba 23000, Algeria
The purpose of this work is to calculate quantum-mechanically the di®usion coe±cients
of atomic potassium in helium as well as the width and shift of the K(4p ! 4s) resonance
line perturbed by He. The di®usion coe±cients of ground K(4s) and excited K(4p) in a
helium bu®er gas are analyzed and the results are compared for few temperatures with
experimental and other theoretical data. Further, the pressure broadening parameters are
treated by using the most recent interatomic potentials, spin-orbit e®ects neglected. The
simpli¯ed Baranger method is particularly used to examine the linewidth and lineshift
coe±cients and their behavior with temperature.
CP 104
126
Pressure broadening of calcium resonance line
perturbed by helium
L. Reggami and M. Bouledroua
Laboratoire de Physique des Rayonnements, Badji Mokhtar University,
B.P. 12, Annaba 23000, Algeria
The aim of this work is to calculate quantum mechanically the width w and shift d of
the neutral calcium lines Ca(4s2 1S) ¡! Ca(4s4p 1P) and Ca(4s2 1S) ¡! Ca (4s4p
3P) perturbed by helium He. The ab initio data points from Paul-Kwiek [1] are used to
construct the potential-energy curves. For the ground state, X1§+, and the four excited
states, 1§+, 1¦, 3§+, and 3¦, the potential data are smoothly connected to the appropriate
long and short forms. The numerical integration of the radial wave equation provides the
elastic phase shifts which allow the computation of the linewidth and lineshift parameters
by adopting the pressure broadening simpli¯ed Baranger model [2]. The results show
there is in general a good agreement with other experimental and theoretical data [3, 4].
References
[1] E. Paul-Kwiek, private communication (2007).
[2] M. Baranger, Phys. Rev. 111, 481 (1958).
[3] A.R. Malvern, J. Phys. B 10, 593 (1977).
[4] J. RÄohe-Hansen and V. Helbig, J. Phys. B 25, 71 (1992).
CP 105
127
Broadening and intensity redistribution in the
atomic hyper¯ne excitation spectra due to optical
pumping in the weak excitation limit
E. Saks1, I. Sydoryk1, N. N. Bezuglov1;2, I. I. Beterov3 , K. Miculis1, and A. Ekers1
1 Laser Centre, University of Latvia, LV-1002 Riga, LATVIA
2 Faculty of Physics, St.Petersburg State University, 198904 St. Petersburg, RUSSIA
3 Institute of Semiconductor Physics SB RAS, 630090, Novosibirsk, RUSSIA
We analyze spectral line broadening and variations in relative intensities of hyper¯ne
spectral components due to optical pumping at exciting laser intensities below the satu-
ration limit. The study was motivated by by the lack of availability of detailed theoretical
models describing such e®ects in partially open level systems. In experiment, the hyper-
¯ne laser-excitation spectra of the Na(3p) state were measured in a supersonic beam as
a function of laser intensity under the conditions when optical pumping time is shorter
than transit time of atoms through the laser beam. The theoretical excitation spectra
were calculated numerically by solving density matrix equations of motion using the split
propagation technique [1; 2].
The following results will be reported: (i) it will be shown that spectral lines can be
signi¯cantly broadened at laser intensities well below the saturation intensity, which is
usually regarded as the threshold for onset of broadening e®ects; (ii) it will be shown that
the presence of dark mF sublevels can vary the e®ective branching coe±cients of the tran-
sitions, and this variation depends on laser intensity. Changes in the e®ective branching
coe±cients lead to irregular changes of peak ratios, like minimum in the intensity de-
pendence of the peak ratio, which deviate from those expected from the given original
branching coe±cients; (iii) analytical expressions will be presented, which allow the cal-
culation of critical values for laser intensity and Rabi frequency, above which linewidths
and peak ratios are notably a®ected by optical pumping. The critical laser intensity can
be expressed via the saturation intensity Isat, the branching coe±cient ¦ of the transition,
and the ratio of natural lifetime and transit time of atoms through the laser beam ¿nat=¿tr:
Icr =
8¼2¹hc
p
¼3¸3
1
¿tr¦(1 ¡ ¦)
=
4¿nat p
¼¿tr (1 ¡ ¦)
Isat : (1)
Importantly, the critical laser intensity depends on the branching coe±cient ¦ and has a
a minimum at ¦ = 1=2, and it can be much smaller than the saturation intensity.
We acknowledge support by EU FP6 TOK Project LAMOL, Latvian Science Council,
and European Social Fund.
References
[1] M. D. Fiet, J. A. Fleck, and A. Steiger, J. Comput. Phys. 47, 412 (1982)
[2] I. Sydoryk, N. N. Bezuglov, I. I. Beterov, K. Miculis, E. Saks, A. Janovs, P. Spels, and
A. Ekers, Phys. Rev. A (2008) in print
CP 106
128
Reconsideration of spectral line pro¯les a®ected by
transit time broadening
B. Mahrov1, C. Andreeva1;2, N. N. Bezuglov1;3, K. Miculis1, E. Saks1, M. Bruvelis1, and
A. Ekers1
1 Laser Centre, University of Latvia, LV-1002 Riga, LATVIA
2Institute of Electronics, Bulgarian Academy of Sciences, So¯a 1784, Bulgaria
3 Faculty of Physics, St.Petersburg State University, 198904 St. Petersburg, RUSSIA
In the weak excitation limit in dilute gases, when saturation and collision e®ects are
negligible, line broadening occurs due to spontaneous decay (width ¡sp), Doppler e®ect,
and, if atoms interact with tightly focused cw laser beams, also due to limited transit time
¿tr of atoms through the laser beam. Consider a two step excitation process, in which
Doppler broadening is avoided using counterpropagating laser ¯elds. The conventional
knowledge says that the the resultant lineshapes are given by the Lorenz pro¯le [1]
P(¢) = ¼e¡=
³
¢2 + e¡2
´
; 2¢! = e¡ = ¡sp + 1=¿tr; (1)
where ¢ is the detuning of the laser ¯elds o® from the two-photon resonance, and 2¢!
is the FWHM width. If an atom from a supersonic beam at a °ow velocity vf crosses a
Gaussian laser beam of FWHM L, then it is reasonable to assume ¿tr = L=vf .
We consider excitation of the Na(5S1=2) HF sublevel F = 2 with lifetime ¿sp = 76ns
by two counter-propagating laser beams, which models an e®ective two-level quantum
system. Laser in the ¯rst step is focused to L1 = 30¹m using a cylindrical lens and
detuned by ¢º1=100MHz o® from resonance with the 3S1=2; F00 = 1 ! 3p1=2; F0 =
2 transition. The second laser is collimated to L2 = 1000¹m, while its frequency is
scanned across the two-photon resonance. The detuning ¢º1 is su±cient to ensure that
the intermediate level is virtual. Both lasers cross the atomic beam with °ow velocity of
vf = 1200m/s at right angles. The time dependence of their Rabi frequencies are given
by ­i(t) = ­(i)
0 exp(¡2t2=¿2
i;tr), which corresponds to a Gaussian laser intensity pro¯les
Ii(z) = I(i)
0 exp(¡4z2=L2
i ) along the atomic beam axis z. The spatial distribution of the
corresponding e®ective Rabi frequency is given by ­eff (z) = ­1(z)­2(z)=¢!1.
We have obtained analytical solutions to this model porlem which show that the lineshape
of excitation of the upper state is described by the Voight pro¯le with FWHM which can
be approximated (within the accuracy level of 10%) by the expression
2¢!res =
q
¡2
sp + 19:2 ¢ ln(2)=¿2
tran: (2)
Importantly, the value of the width 2¢!res exceeds the intuitive one 2¢! (1) by a factor
of four if the broadening occurs predominantly due to limited transit time, i.e. when
¿tran < 1=¡sp = ¿sp.
We acknowledge support by EU FP6 TOK Project LAMOL (Contract MTKD-CT-2004-
014228), Latvian Science Council, European Social Fund.
References
[1] B.W.Shore, The Theory of Coherent Atomic Excitation (Wiley, New York, 1990).
CP 107
129
Alkali doped Helium Droplets in a Magnetic Field
G. AubÄock, J. Nagl, C. Callegari, W.E. Ernst
Institute of Experimental Physics, Graz University of Technology, Austria
Helium nanodroplets are produced by supersonic free jet expansion and provide a cold
environment (T ¼ 0.4 K) for dopant atoms and molecules. Helium droplets can dissipate
energy very e±ciently by evaporating some of their own atoms. Alkali atoms are de-
posited onto the droplet by passing the droplet beam through one or more heated pick-up
cells containing alkali vapor. Capture of multiple atoms per droplet leads to molecular
formation; alkali-metal species are unique dopants in that they remain on the droplet's
surface. Most degrees of freedom of dopant atoms and molecules are immediately cooled
to the droplet's internal temperature and the energy released leads to further evaporation
of helium atoms. This applies in particular to the energy of formation of complexes, which
may be large enough to cause them to be expelled from the droplet: due to their smaller
binding energy it is the high spin alkali complexes (triplet dimers, quartet trimers) which
preferentially remain on the droplet after formation.
High-spin molecules are very interesting systems, and relate to a variety of topics such as
Bose-Einstein condensation, molecule formation by photoassociation or magnetic tuning,
many-body forces, reactivity and magnetism of small metal clusters, the Jahn-Teller e®ect,
electron- and nuclear-spin resonance.
Here we summarize several results of our investigations of alkali doped He droplets in a
magnetic ¯eld. This series of experiments was initially started to investigate the feasibility
of optical preparation and detection of spin states for further electron spin resonance
experiments. For atom doped droplets (K and Rb) we found that the spin state does
not thermalize with the He droplet on the time scale of our experiment (we can extract
a relaxation rate <1000/s). Usually alkali atoms (molecules) are evaporated from the
droplet surface upon electronic excitation what can be used for the preparation of a spin
polarized beam by spin selective optical depletion for K. Contrary to common wisdom,
we found that nondestructive excitation is possible at the Rb D1 line, this makes optical
pumping feasible.
Unlike atoms, the spin state fully thermalizes with the internal temperature of the droplet
for dimers and trimers. Then the population di®erence of the ground state Zeeman
sublevels causes the appearance of a C-type magnetic circular dichroism (MCD). In fact
the amplitude of the MCD signal can be used to determine the temperature on the droplet
surface which is a priori not necessarily equal to the temperature measured in the interior.
For dimers, the MCD spectrum further allowed us to interpret consistently the structure
of (1)3¦g - (a)3§+
u transitions for several molecules (K2, Rb2, Cs2, KRb, LiCs, NaCs) as
an interplay of a perturbation of the excited state electronic wave function by the droplet
surface and spin orbit coupling. For trimers we investigated the LIF and MCD spectra
of the (2)4E0 - (1)4A0
2 transition of K3 and Rb3. We interpret these spectra as e­E
vibronic coupling plus spin-orbit coupling. This is to our knowledge the ¯rst observation
of relativistic vibronic coupling in a quartet states.
CP 108
130
Quartet alkali trimers on He nanodroplets: Laser
spectroscopy and ab initio calculations
J. Nagl, G. Aub¨ock, A. W. Hauser, O. Allard, C. Callegari, and W. E. Ernst
Institute of Experimental Physics, Graz University of Technology, Graz, Austria
Helium nanodroplets (N = 104) are produced by supersonic free jet expansion and provide
a cold environment (T = 0.4 K) for dopants; the droplets can dissipate energy very
efficiently by evaporating their own atoms (binding energy per He atom: 5 cm−1). Alkali
atoms are deposited on the helium surface by passing the droplet beam through one
or more heated pick-up cells containing alkali vapor. Capture of multiple atoms per
cluster leads to molecular formation. Due to the amount of binding energy released
into the cluster, in general a strongly bound low-spin molecule will be expelled from
the droplet beam, while a weakly bound high-spin van der Waals molecule will not. A
variety of electronic spectra of the homo- and heteronuclear trimers K3, Rb3, K2Rb and
KRb2 in their high-spin quartet state lie in the wavelength range 10500–17500 cm−1. We
measured them and applied various schemes of beam depletion spectroscopy, such as twolaser
excitation and mass-selective depletion to separate overlapping spectral features,
and to assign the individual bands.
We find several regular patterns in the spectra of these trimers, which we are in the
process of explaining by means of symmetry arguments and simplified models of their
level structure. The experiments are supported by high-level ab-initio electronic structure
calculations.
References
[1] Johann Nagl, Gerald Aub¨ock, Andreas W. Hauser, Olivier Allard, Carlo Callegari,
and Wolfgang E. Ernst. Heteronuclear and homonuclear high-spin alkali trimers on
helium nanodroplets. Phys. Rev. Lett. 100, 063001 (2008).
[2] Johann Nagl, Gerald Aub¨ock, Andreas W. Hauser, Olivier Allard, Carlo Callegari,
and Wolfgang E. Ernst. High-spin alkali trimers on helium nanodroplets: Spectral
separation and analysis. J. Chem. Phys. 128, 154320 (2008).
CP 109
131
Group Dynamics of 2-Atom Even-Electron Molecules
and Ions
R. Hefferlin
Physics Department, Southern Adventist University
Collegedale, Tennessee 37315, United States of America
E-mail: hefferln@southern.edu
The group SO(3) is used to characterize even-electron atoms on the basis of their electron
counts. The atoms are arranged in multiplets that have “chemical angular momentum”
quantum numbers l and z-component m
l [1-3]. Atoms in group 2 have (l,m
l) = (0,0);
atoms in groups 14, 16, and 18 have l = 1 and m
l = -1, 0, +1. Negatively-charged atoms
of groups 1, 13, 15, and 17 have the same quantum numbers; unipositive ions of atoms in
groups 3, 15, 17, and (from the next higher period number) 1 also have the same quantum
numbers; more highly-ionized species follow the same pattern.
Odd-electron atoms may be characterized in the very same way. Neutral atoms in group
1 have (l,m
l) = (0,0); atoms in groups 13, 15, and 17 have l = 1 and m
l = -1, 0, +1.
Their ions follow the same pattern. Likewise, transition-metal and rare-earth atoms are
arranged in multiplets with l = 2 and 3. (The period numbers are not defined in the
algebra and may be chosen at will.)
Atoms or ions are now defined as vectors in the space H(1). The bosonic raising operator
of SO(3) [4,5] is used to combine two even-electron multiplets, or two odd-electron
multiplets, of atoms or ions to form multiplets of even-electron vectors in the space H(2)
of diatomic molecules and ions. These multiplets are then combined, using an empirical
function of the two period numbers, to construct the group-dynamic periodic system
of the even-electron gas-phase diatomic species. Some forecasted data for spectroscopic
properties of the species are presented.
References
[1] Y.B. Rumer, A.I. Fet, Teor. Mat. Fiz. (Russ.) 9, 203 (1971)
[2] A.I. Fet, Theor. Math. Phys. 22, 227 (1975)
[3] A.O. Barut, Group Structure of the Periodic System, in B. Wybourne, Ed., Structure
of matter (Proceedings of the Rutherford Centennary Symposium, 1971): University of
Canterbury Press, Canterbury, 1972, pp. 126-136.
[4] G.V. Zhuvikin, R. Hefferlin, The Periodic system of Diatomic Molecules: Group-
Theoretical Approach, Vestnik Leningradskovo Universiteta, No. 16, 1983, pp. 10-16.
[5] G.V. Zhuvikin, R. Hefferlin, Joint Report #1 of the Physics Departments of Southern
College [SAU], Collegedale, TN, USA and St. Petersburg University, St. Petersburg,
Russia, Southern Adventist University: Collegedale, Tennessee, 1994.
CP 110
132
Cavity-QED with ion Coulomb crystals
A. Dantan, P. Herskind, J. Marler, M. Albert, M.B. Langkilde-Lauesen, M. Drewsen
QUANTOP, Department of Physics and Astronomy, University of Aarhus,
Ny Munkegade, bygning 1520, D8000 Aarhus, Denmark
In addition to its fundamental interest for atom-light studies, Cavity Quantum Electro-
dynamics (CQED) represents an interesting avenue for engineering e±cient light-matter
quantum interfaces for quantum information processing. Experiments with neutral atoms
have been very successful in strongly coupling single atoms to cavities of extremely small
mode volume and very high ¯nesse. However, these experiments are challenged by the
di±culty in con¯ning and storing the atoms in the cavity for a long time [1].
Ions, on the other hand, have proved to be an excellent medium for quantum information
processing and bene¯t from very long trapping times, a good localization and are robust
against decoherence. However, minimizing the mirror separation, without severely modi-
fying the trapping potential has made it extremely di±cult to reach the strong coupling
regime with a single ion [2,3]. The small mode volume requirement can be relaxed for en-
sembles of atoms or ions due to the enhancement of the collective coupling strength of the
ensemble. In addition to tight con¯nement and long storage times, ion Coulomb crystals
also have a number of advantages over cold atomic samples. As the ions are con¯ned in
a crystal lattice, the decoherence rate due to collisions is very low and their low optical
densities (108cm¡3) make optical pumping and state preparation unproblematic. Finally,
the inherent lattice structure in conjunction with the standing wave ¯eld of the optical
resonator opens up for new possibilities to engineer the atom-photon interaction.
We will present recent experimental results on CQED with cold ion Coulomb crystals of
calcium, obtained by using a novel linear ion trap incorporating a moderately high ¯nesse
cavity (F » 3200). Even though the 3-mm diameter dielectric cavity mirrors are placed
between the trap electrodes and separated by only 12 mm, it is possible to produce in situ
ion Coulomb crystals containing more than 105 calcium ions of various isotopes and with
lengths of up to several millimetres along the cavity axis [4]. Single to a few thousands of
ions can be stored in the cavity mode volume and e±ciently prepared by optical pumping
in a given magnetic substate of the metastable 4d2D3=2 level of 40Ca+. The ¯rst results
on the crystal-light coupling strength - evaluated by probing the ion-cavity system at the
single photon level - and the possibilities for CQED o®ered by this new system will be
discussed.
[1] P.R. Berman (Ed.) Cavity Quantum Electrodynamics, Academic Press inc., London
(1994)
[2] M. Keller, B. Lange, K. Hayasaka, W. Lange, H. Walther, Nature 431, 1075 (2004)
[3] A.B. Mundt, A. Kreuter, C. Russo, C. Becher, D. Leibfried, J. Eschner, F. Schmidt-
Kaler, R. Blatt, Appl. Phys. B 76, 117 (2003)
[4] P. Herskind, A. Dantan, M.B. Langkilde-Lauesen, A. Mortensen, J. L. S¿rensen, M.
Drewsen, quant-ph/0804.4589.
CP 111
133
Spin flip lifetimes in superconducting atom chips
Ulrich Hohenester1, Asier Eiguren2, Stefan Scheel3, and E. A. Hinds3
1Institut f¨ur Physik, Karl–Franzens–Universit¨at Graz, Austria
2Donostia International Physics Center (DIPC), San Sebastian, Spain
3Quantum Optics and Laser Science, Imperial College London, United Kingdom
Over the last few years, enormous progress has been made in magnetic trapping of ultracold
neutral atoms near microstructured solid-state surfaces, sometimes known as atom
chips [1]. The atoms can be manipulated through variation of the magnetic confinement
potential, either by changing currents through gate wires mounted on the chip or by
modifying the strength of additional radio-frequency control fields. These external, timedependent
parameters thus provide a versatile method of atom manipulation, and make
atom chips attractive for various applications, including atom interferometry, quantum
gates and coherent atom transport.
The proximity of the ultracold atoms to the solid-state structure introduces additional
decoherence channels, which limit the performance of the atoms. Most importantly,
Johnson-Nyquist noise currents in the dielectric or metallic surface arrangements produce
magnetic-field fluctuations at the positions of the atoms. Upon undergoing spin-flip
transitions, the atoms become more weakly trapped or are even lost from the microtrap.
This constitutes a serious limitation for atom chips. Superconductors could reduce the
magnetic noise level significantly and thereby boost the spin flip lifetimes by many orders
of magnitude. Indeed, superconducting atom chips have already been fabricated and
tested [2, 3] with the aim of realizing controllable composite quantum systems.
In this contribition we investigate theoretically the magnetic spin-flip transitions of neutral
atoms trapped near a superconducting slab [4, 5]. We find that below the superconducting
transition temperature the spin-flip lifetime becomes boosted by several orders
of magnitude, a remarkable finding which is attributed to: (1) the opening of the superconducting
gap and the resulting inability to deposit energy into the superconductor,
(2) the highly efficient screening properties of superconductors, and (3) the small active
volume within which current fluctuations can contribute to field fluctuations. Our numerical
results based on the Eliashberg theory show that the expected spin-flip lifetime
for an atom placed one micrometer away from a 4.2 K superconducting planar niobium
surface exceeds several thousand seconds. Hence, superconducting surfaces provide an
extremely low-noise environment for magnetically trapped neutral atoms and thus have
great potential for coherent manipulation of atoms.
References
[1] J. Fortagh and C. Zimmermann, Rev. Mod. Phys. 79, 235 (2007)
[2] T. Nirrengarten, A. Qarry, C. Roux, A. Emmert, G. Nogues, M. Brune, J. M. Raimond,
and S. Haroche, Phys. Rev. Lett. 97, 200405 (2006)
[3] C. Roux, A. Emmert, A. Lupascu, T. Nirrengarten, G. Nogues, M. Brune, J.-M.
Raimond, and S. Haroche, Euro. Phys. Lett. 81, 56004 (2008)
[4] B. S. Skagerstam, U. Hohenester, A. Eiguren and P. K. Rekdal, Phys. Rev. Lett. 97,
070401 (2006)
[5] U. Hohenester, A. Eiguren, S. Scheel, and E. A. Hinds, Phys. Rev. A 76, 033618
(2007)
CP 112
134
Interaction-Free Measurement of the Degree of
Polarization of an Atomic Ensemble
Alessandro Cer e;1 Valentina Parigi;2 Marta Abad;1 Florian Wolfgramm;1
Ana Predojevic1 and Morgan W. Mitchell1
1ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, Castelldefels,
08860 Barcelona, Spain
2LENS, Via Nello Carrara 1, 50019 Sesto Fiorentino, Florence, Italy
In the last years, several proposals for quantum information and quantum communication
schemes require the use of atomic media together with single photons. Among the possible
interactions, much interest has been generated by non destructive techniques, like the
quantum non-demolition measurement. We present here instead a characterization of the
polarization state of an atomic sample via the non-interaction of our sample with the
probe, thus reducing, in principle, the damage to the sample for successful event to zero.
The term \interaction-free" applies to a measurement process where the probe carries
information about a system without interacting with it, possible thanks to the quantum
nature of the interference process. After the proposal of Elitzur and Vaidman [1], an
experimental demonstration was provided by Kwiat et al. [2]. We have realized an inter-
action free measurement of the spectrum and polarization state of a hot ensemble of 87Rb
by inserting it in a polarization interferometer, where a di erent optical density for one of
the polarization modes is revealed by detection of light at the output dark in the balanced
case The probe is a narrowband coherent light, strongly attenuated to the single photon
level, with a central frequency that can be scanned by some GHz in the region of the Rb
D1 line. The atoms are optically pumped by an intense beam into the mF =1,2 Zeeman
substates of the F=2 hyper ne level. Observing the output of the dark port while scan-
ning the probe frequency, the obtained trace presents a peak in correspondence with the
transitions involving the hyper ne ground level F=2. The pro le of the trace corresponds
to the pro le of the transition, power broadened by the intense pumping necessary for
polarization.
The demonstrated scheme su ers from limited statistical e ciency, equal to 1/4 in theory
and further reduced because of experimental imperfections. It has been demonstrated
that combining the interaction free measurement approach and an implementation of
the quantum Zeno e ect it is possible reach a theoretical e ciency close to unity [3].
Moreover, this scheme could be used to measure the degree of polarization of a sample of
atoms reducing the damage compared with standard absorption techniques [4].
References
[1] A. Elitzur and L. Vaidman, Foundations of Physics 23, 987 (1993).
[2] P. G. Kwiat et al., Phys. Rev. Lett. 74, 4763 (1995).
[3] P. G. Kwiat et al., Phys. Rev. Lett. 83, 4725 (1999).
[4] P. Facchi et al., Phys. Rev. A 66, 012110 (2002).
CP 113
135
Entangled atom-pairs from dissociated dimers:
an experimental test of Bell inequality for atoms
J. Koperski1, M. Kro´snicki2, and M. Strojecki1
1Smoluchowski Institute of Physics, Jagiellonian University
Reymonta 4, 30-059 Krakow, Poland
2Institute of Theoretical Physics and Astrophysics
University of Gdansk, Wita Stwosza 57, 80-952 Gdansk, Poland
E-mail: ufkopers@cyf-kr.edu.pl
In 1964 Bell showed that in all local realistic theories, correlations between the outcomes
of measurements in different parts of a physical system satisfy certain class of inequalities
[1]. Furthermore, he found that certain predictions of quantum mechanics violate these
inequalities. Starting with the first experimental tests of Bell inequalities with photons
[2], violation of a Bell inequality has been observed for protons [3], K mesons [4], ions [5],
neutrons [6], B mesons [7], atom-photon systems [8], and atomic ensembles [9].
Production of entangled atom-pairs via stimulated two-photon Raman dissociation of
dimers produced in supersonic free-jet pulsed beam will be described. The process re-
lies on the proposal of Fry et al. [10] for experimental realization of Bohm’s spin-1/2
particle version of the Einstein-Podolsky-Rosen (EPR) experiment. The first stage of
the experiment, designed for 199Hg atoms, is underway at Texas A&M University. The
real challenge is to isolate a particular rotational transition within a triplet-singlet D31u–
X110+
g
electronic transition in 199Hg2 propagating in the beam [11], and then dissociate
the excited isotopomer using a stimulated Raman process. Pairs of entangled 199Hg atoms
obtained in this way are going to be spin-state-selectively detected in two different atom
detectors located in two parallel planes of detection.
An alternative approach is to selectively dissociate 111Cd2 isotopomers produced in a
continuous supersonic free-jet using selected rotational transition within a singlet-singlet
A10+
u
–X10+
g
electronic transition in 111Cd2. During the conference the advantages of using
the latter approach and recent developments in the endeavor of testing Bell inequality for
111Cd atoms planned in Krakow will be reported.
This work was financed from 2007-2010 funds for science of Polish Ministry of Science
and Higher Education (research project N N202 2137 33).
References
[1] J.S. Bell, Physics (Long Island City, N.Y.) 1, 195-200 (1964).
[2] S.J. Freedman, J.F. Clauser, Phys. Rev. Lett. 28, 938-941 (1972).
[3] M. Lamehi-Rachti, W. Mittig, Phys. Rev. D14, 2543-2555 (1976).
[4] A. Bramon, M. Nowakowski, Phys. Rev. Lett. 83, 1-5 (1999).
[5] M.A. Rowe et al., Nature (London) 409, 791-794 (2001).
[6] Y. Hasegawa et al., Nature (London) 425, 45-48 (2003).
[7] A. Go, J. Mod. Opt. 51, 991-998 (2004).
[8] D. L. Moehring et al., Phys. Rev. Lett. 93, 090410 (2004).
[9] D. N. Matsukevich et al., Phys. Rev. Lett. 96, 030405 (2006).
[10] E. Fry, T. Walther, S. Li, Phys. Rev. A 52, 4381-4395 (1995).
[11] J. Koperski et al., Chem. Phys. (2008), in press.
CP 114
136
Primary gas thermometry by means of near-infrared
laser absorption spectroscopy and determination of
the Boltzmann constant
G. Casa1, A. Castrillo1, G. Galzerano2, R. Wehr1, A. Merlone3, D. Di Sera¯no4, P.
Laporta2 and L. Gianfrani1;y
1Dipartimento di Scienze Ambientali, Seconda Universitµa di Napoli, Caserta, Italy
2Dipartimento di Fisica, Politecnico di Milano and Istituto di Fotonica e Nanotecnologie
(IFN-CNR), Milano, Italy
3 Istituto Nazionale di Ricerca Metrologica, Torino, Italy
4Dipartimento di Matematica, Seconda Universitµa di Napoli, Caserta, Italy
ylivio.gianfrani@unina2.it
We report on a new method for primary gas thermometry, based on high-precision,
intensity-stabilized laser absorption spectroscopy in the near-infrared. Initially designed
and developed for the accurate determinations of absolute linestrength factors [1], the
method consists in retrieving the Doppler width from the absorption line shape corre-
sponding to a given vibration-rotation transition in a CO2 gaseous sample at thermo-
dynamic equilibrium. There is presently a strong interest in new primary thermometric
methods, likely to be employed for direct and highly accurate determinations of the Boltz-
mann constant kB, in view of a possible new de¯nition of the unit kelvin [2].
We probed the R(12) component of the º1+2º 0
2 +º3 combination band, using a distributed
feedback diode laser, which was mounted in a mirror-extended cavity con¯guration. Con-
sisting of a cylindrical cavity inside an aluminum block, with inner and external surfaces
carefully polished, the absorption cell was housed inside a stainless steel vacuum chamber
and its temperature was stabilized at a level of »10 mK by means of an active system
based on four Peltier elements and a PID controller. The gas temperature was measured
by means of precision platinum resistance thermometers, carefully calibrated at the triple
point of water and at the gallium melting point with an overall accuracy better than 10
mK. By doing Doppler broadening measurements as a function of the gas temperature,
which was varied between 270 and 305 K, we determined the Boltzmann constant with
an uncertainty of 1:6 £ 10¡4, including statistical and systematic errors [3].
We also report on the status of a second-generation experiment, in which a pair of phase-
locked extended-cavity diode lasers are being employed in order to improve signi¯cantly
the capability of measuring laser frequency variations.
References
[1] G. Casa, D. A. Parretta, A. Castrillo, R. Wehr, and L. Gianfrani, J. Chem. Phys.
127, 084311 (2007)
[2] B. Fellmuth et al., Meas. Sci. Technol. 17, R145 (2006)
[3] G. Casa, A. Castrillo, G. Galzerano, R. Wehr, A. Merlone, D. Di Sera¯no, P. Laporta
and L. Gianfrani, Phys. Rev. Letters, in press
CP 115
137
Towards precision spectroscopy in the XUV
Valentin Batteiger1, Maximilian Herrmann1, Sebastian Knunz1, Akira Ozawa1, Andreas
Vernaleken1, Guido Saatho 1, Mariusz Semczuk1, Feng Zhu2, Hans Schuessler2, Theodor
W. Hansch1 and Thomas Udem1
1Max-Planck-Institut fur Quantenoptik, Hans-Kopfermann-Strasse 1, D-85748 Garching
2Department of Physics, Texas A&M University, College Station, Texas 77843, USA
Recent developments of XUV frequency combs [1],[2] open up the possibility of high
resolution spectroscopy in the XUV wavelength regime. The 1s-2s two photon transition
in hydrogen-like Helium at 60 nm is a particular interesting candidate allowing a further
test of bound state QED. Our proposed spectroscopy scheme is based on the detection
of ionization events out of the 2s state and sympathetic cooling by co-stored Magnesium
ions in a RF-trap. Experimental progress is presented, including an absolute frequency
measurement on cooling transitions in Mg+.
References
[1] C. Gohle et. al., Nature 436, 234 (2005)
[2] R. J. Jones et al., PRL 94, 193201 (2005)
CP 116
138
Probing isotope e®ects in chemical reactions using
single ions
Peter F. Staanum1, Klaus H¿jbjerre1, Roland Wester2 and Michael Drewsen1
1Department of Physics and Astronomy, University of Aarhus, Aarhus, Denmark
2Physikalisches Institut, UniversitÄat Freiburg, Freiburg, Germany
Isotope e®ects often play an important role for the outcome of chemical reactions. For
instance the chemical composition of interstellar clouds is strongly in°uenced by isotope
e®ects in certain reactions [1]. In laboratory experiments, isotope e®ects observed in
isotopic analogs of chemical reactions can provide important information about details of
the reaction dynamics.
Here we present a recent study of isotope e®ects, in reactions between Mg+ in the 3p 2P3=2
excited state and molecular hydrogen at thermal energies, through single reaction events
observed in a Paul trap [2]. From only »250 reactions with HD, the branching ratio
between formation of MgD+ and MgH+ is found to be larger than 5. From additional 65
reactions with H2 and D2 we ¯nd that the overall decay probability of the intermediate
MgH+
2 , MgHD+ or MgD+
2 complexes is the same. These results suggest that the observed
isotope e®ect in reactions with HD arise through a dynamic mechanism in the exit channel
of the reaction, which may also explain the isotope e®ect observed in reactions with ground
state Mg+ ions at much higher collision energies [3].
Our study shows that few single ion reactions can provide quantitative information about
branching ratios and relative reaction rate coe±cients in ion-neutral reactions. Hence,
the method is particularly well suited for reaction studies involving rare species, e.g.,
rare isotopes or short-lived unstable elements, as well as for studies involving state pre-
pared molecular ions [4], more complex molecular ions [5; 6] or of astrophysically relevant
reactions [7; 8].
References
[1] T. J. Millar, Space Science Reviews 106, 73 (2003).
[2] P. F. Staanum, K. H¿jbjerre, R. Wester and M. Drewsen, arXiv:0802.2797v1.
[3] N. Dalleska, K. Crellin and P. Armentrout, J. Phys. Chem. 97, 3123 (1993).
[4] I. S. Vogelius, L. B. Madsen and M. Drewsen, Phys. Rev. Lett. 89, 173003 (2002);
Phys. Rev. A 70, 053412 (2004).
[5] A. Ostendorf et al., Phys. Rev. Lett. 97, 243005 (2006).
[6] K. H¿jbjerre et al., Phys. Rev. A 77, 030702(R) (2008).
[7] D. Gerlich, E. Herbst and E. Roue®, Planetary and Space Science 50, 1275 (2002).
[8] S. Trippel et al. Phys. Rev. Lett. 97, 193003 (2006).
CP 117
139
Laser cooling of unbound atoms in nondissipative
optical lattice
N. A. Matveeva1, A. V. Taichenachev1;2, A. M. Tumaikin1 and V. I. Yudin1;2.
1 Novosibirsk State University
Pirogova 2, 630090 Novosibirsk, Russia
2Institute of Laser Physics SB RAS
Lavrenteva 13/3, 630090 Novosibirsk, Russia
E-mail: matveeva1314@ngs.ru
Laser cooling of neutral atoms plays a very important role in optical metrology. In particular,
the transversal cooling (collimation) of an atomic beam below ¹K would allow one
to achieve the higher precision and stability in the modern atomic frequency standards
(atomic fountains, atomic clock in condition of microgravitation). This collimation can
be made by the method of sideband-resolved Raman cooling (SRLC). The experiments
on SRLC of neutral cesium atoms [1] were carried out in the 2D nondissipative (far-o -
resonance) optical lattice with pre-cooling in a near-resonance lattice, which complicated
experimental realization. Similar experiments on the high-e ective 3D - SRLC were made
without pre-cooling stage [2], but the exhaustive theoretical explanation of high cooling
e ciency has not been presented. Then SRLC was applied at the attempt of the improvement
of the continuous atomic fountain [3]. In these experiments one used 2-D cooling
scheme similar to described in [2]. However, the e ciency of cooling was poor and appreciably
lower in comparison with the previous results [2]. The causes of this were not
explained. Thus the necessity of more detailed investigation of cooling in nondissipative
optical lattices has arisen. One of the purposes of such consideration is to nd the elds
of parameters where cooling mechanisms of unbound and bound atoms co-exist.
In the present work the semiclassical approach is applied for the analysis of cooling of
unbound atoms with optical transitions J ! J ¡ 1 in a one-dimensional nondissipative
optical lattice. For slow atoms in the low-saturation limit the analytical expressions for
coe cients of friction and di usion are obtained for the simplest 1 ! 0 transition. However,
in this case it is necessary to go beyond the slow atom approximation for the full
description of atomic kinetic. For this purpose the dependence of force on atom and the
coe cient of di usion on the atomic velocity are found. At the weak Raman transition the
heating takes place for small velocity that corresponds to the results of the slow atom approximation.
At the increasing of atomic velocity the direction of kinetic process changes
and cooling occurs. In addition there are the selective velocity Raman resonances in the
force, that have some speci c features for J ! J ¡ 1 atomic transitions. The kinetic
temperature is estimated on the base of the numerical solution of Fokker-Plank equation
for Wigner distribution function.
References
[1] S. E. Hamann, D. L. Haycock, G. Klose et al., Phys. Rev. Letters 80, 4149 (1998)
[2] A. J. Kerman, V. Vuletic, C. Chin, and S. Chu, Phys. Rev. Letters 84, 439 (2000)
[3] G. Di Domenico, N. Castanga, G. Mileti et al., Phys. Rev. A 69, 063403 (2004)
CP 118
140
Investigations on the linjj lin CPT and its application
in quantum sensors
R. Lammegger1, E. Breschi2, G. Kazakov3, G. Mileti2, B. Matisov3 and L. Windholz1
1Institute of Experimental Physics TU-Graz, Petersgasse16, 8010 Graz
2Laboratoire Temps-Fr¶equence, University of Neuch^atel, rue A.-L.-Breguet 1, CH-2000
Neuch^atel
3St. Petersburg State Polytechnic University, Polytechnicheskaya 29, 195251 St.
Petersburg, Russia
Coherent Population Trapping (CPT) is a resonance phenomenon due to a quantum
mechanical interference e®ect in an atomic system. The resonantly driven atomic level
population is being trapped into a so called dark state, yielding the atomic medium
transparent for the exciting electromagnetic ¯elds.
We present experimental investigations on the behavior of CPT resonances in Rubidium
(87Rb Isotope) due to the interaction of a linear polarized bichromatic laser light (linjj lin
CPT) in presence of longitudinal magnetic ¯elds[1]. In this con¯guration the coherence
has a quadrupol like nature and is strongly in°uenced by the hyper¯ne structure of the
excited state. The hyper¯ne structure of the excited states gives rise to degenerate CPT
resonances. By comparing the multi-level model calculations with the experimental re-
sults we demonstrate that the quantum interference between the multi-CPT states is an
essential feature in this interaction scheme.
We investigate the linjj lin CPT signal depending on the relationship of pressure broad-
ening and laser linewidth. Therefore CPT signals obtained by excitation with a vertical
surface emitting laser system (linewidth 100MHz) and a system of phase locked lasers
(linewidth 40kHz) are compared. The experimental and theoretical results allow us to
quantify the contribution from di®erent CPT-states to the total linjj lin CPT signal. Based
on our experiment, we can de¯ne the conditions in which the laser linewidth does not de-
grade the amplitude of the linjj lin CPT signal and, thus the optimal performance for
compact atomic clocks and magnetometers based on linjj lin CPT.
References
[1] E. Breschi, G. Kazakov, R. Lammegger, G. Mileti, B. Matisov and L. Windholz,
arXiv:0804.4627v1 [quant-ph]
CP 119
141
Optically Driven Atomic Coherences:
From the Gas Phase to the Solid State
J. Klein, F. Beil, and T. Halfmann
Institute of Applied Physics, Technische Universitat Darmstadt, Germany
Coherent interactions between strong radiation and quantum systems provide well-estab-
lished tools to control optical properties and processes. Among others, applications aim
at e cient data storage and processing of optically stored data, e.g. as required in quan-
tum information processing. Thus, a large number of experimental studies in quantum
information science have been conducted in atomic media in the gas phase. Only few ex-
periments on coherent, adiabatic interactions were conducted in solid state media. Appro-
priate solid materials for such investigations are quantum dots, color centers, or rare-earth
doped solids. The latter combine the advantages of atoms in the gas phase, i.e. spectrally
narrow transitions and long dephasing times, with the advantages of solids, i.e. large den-
sity and scalability. In the talk we present implementations of coherent interactions in a
rare-earth doped solid, i.e. a Pr:YSO crystal [1]. In particular we report on the experimen-
tal implementation of stimulated Raman adiabatic passage (STIRAP) in Pr:YSO. Our
data provide clear and striking proof for complete population inversion between hyper ne
levels in the Praseodymium dopants. Time-resolved absorption measurements serve to
monitor the adiabatic population dynamics during the STIRAP process. We will discuss
the possibilities of STIRAP and related techniques to drive atomic coherences in the solid
state environment, e.g. for applications in optical and quantum information processing.
References
[1] J. Klein, F. Beil, and T. Halfmann, Phys. Rev. Lett. 99, 113003 (2007)
CP 120
142
Slowing light and coherent control of susceptibility in
a duplicated two-level system
F.A. Hashmi, M.A. Bouchene
Laboratoire de Collision Agr´egats R´eactivit´e, C.N.R.S UMR 5589, IRSAMC
Universit´e Paul Sabatier, 118 Route de Narbonne, 31062 TOULOUSE, FRANCE
We present a new method of slowing light that can be realized in a double two level system
by exciting it with two orthogonally polarized light pulses that propagate along different
axis 1. Spatio-temporal dephasing of the total polarization induces a grating in the ground
zeeman coherence. The stronger of the two fields (the control field) is diffracted from this
grating into the direction of the weak probe field compensating for the absorption of this
latter field. A transparency window is thus created in the absorption spectrum of the
probe leading to the slowing down of light [Fig. 1(a)]. The transparency window exhibits
characteristics identical to the one obtained by EIT method. However, the important
difference between our method and the traditional EIT method is that ours doesn’t rely
on realizing dark state in the system. This may open the possibility of slowing down light
in more complex atomic media.
-4 -2 0 2 4
-0.4
-0.2
0.0
0.2
0.4
-4 -2 0 2 4
0.0
0.2
0.4
0.6
0.8
1.0
Susceptibility (in units of 2 0k-1)
(in units of )
Re( )
= 0
= 0.3
= 0.6
Im( )
(a) Transparency window for the
probe.
-4 -2 0 2 4
-0.5
0.0
0.5
1.0
Re eff
Im eff
=0
= /2 =3 /4
= /4
-4 -2 0 2 4
-1.0
-0.5
0.0
0.5
-4 -2 0 2 4
-1.0
-0.5
0.0
0.5
eff in units of 2 0k-1
in units of
-4 -2 0 2 4
-0.5
0.0
0.5
1.0
(b) Coherent control of susceptibility.
Figure 1: Real and Imaginary parts of the susceptibility.
is the strength of the control
field, is the detuning for the probe in (a) and detuning of both probe and control in (b)
For the case when the two fields have the same frequency and the same axis of propagation,
linear susceptibility vanishes and higher order, phase dependent non-linear susceptibility
becomes important, allowing coherent control of the optical response of the medium 2.
Coherent control of the medium gain for double two level system in the femtosecond
pulse regime has already been discussed 3. Here we demonstrate that for long pulses the
effective susceptibility for the probe behaves as
lin
e
−2
i where
lin is linear susceptibility
and is the phase difference between two fields. Depending on the relative phase between
the two fields the system can be converted into an absorber or the gain medium for the
probe with normal or anomalous dispersion [Fig. 1(b)]. At larger optical thickness, phase
growth during propagation destroys this coherent control and effective susceptibility turns
into

lin
,turning an absorber into an amplifier without effecting the dispersion.
1F.A. Hashmi and M.A. Bouchene, Slowing light through Zeeman Coherence Oscillations in a dupli-
cated two-level system, submitted to Phys.Rev.A (2008)
2F.A. Hashmi and M.A. Bouchene, Coherent control of the effective susceptibility through wave mixing
in a duplicated two-level system (2008), submitted to Phys.Rev.Lett.
3J.C. Delganes and M.A. Bouchene, Phys. Rev. Lett. 98, 053602 (2007)
CP 121
143
Rydberg excitation of a Bose–Einstein condensate
T. Pfau , R. Heidemann,U. Raitzsch, V. Bendkowsky, B. Butscher, R. L¨ow
5. Physikalisches Institut, Universit¨at Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart,
Germany
t.pfau@physik.uni-stuttgart.de
Rydberg atoms provide a wide range of possibilities to tailor interactions in a quantum
gas. Here we report on Rydberg excitation of Bose-Einstein condensed 87Rb atoms. The
Rydberg fraction was investigated for various excitation times and temperatures above
and below the condensation temperature. The excitation is locally blocked by the van der
Waals interaction between Rydberg atoms to a density-dependent limit. Therefore the
abrupt change of the thermal atomic density distribution to the characteristic bimodal
distribution upon condensation could be observed in the Rydberg fraction. The observed
features are reproduced by a simulation based on local collective Rydberg excitations [1].
The excitation dynamics was investigated for a large range of densities and laser intensities
and shows a full saturation and a strong suppression with respect to single atom
behaviour. The observed scaling of the initial increase with density and laser intensity
provides evidence for coherent collective excitation. This coherent collective behaviour,
that was observed for up to several thousand atoms per blockade volume is generic for
all mesoscopic systems which are able to carry only one single quantum of excitation [2].
Despite the strong interactions the evolution can still be reversed by a simple phase shift
in the excitation laser field. We experimentally prove the coherence of the excitation in
the strong blockade regime by applying an optical rotary echo technique to a sample of
magnetically trapped ultracold atoms, analogous to a method known from nuclear magnetic
resonance. We additionally measured the dephasing time due to the interaction
between the Rydberg atoms. [3]
References
[1] R. Heidemann, U. Raitzsch, V. Bendkowsky, B. Butscher, R. L¨ow, and T. Pfau
”Rydberg excitation of Bose-Einstein condensates”
Phys. Rev. Lett. 100 , 033601 (2008).
[2] R. Heidemann, U. Raitzsch, V. Bendkowsky, B. Butscher, R. L¨ow, L. Santos, T. Pfau
”Evidence for coherent collective Rydberg excitation in the strong blockade regime”
Phys. Rev. Lett. 99, 163601 (2007).
[3] U. Raitzsch, V. Bendkowsky, R. Heidemann, B. Butscher, R. L¨ow, T. Pfau
”An echo experiment in a strongly interacting Rydberg gas”
Phys. Rev. Lett. 100 , 013002 (2008).
CP 122
144
Progress towards a high-precision measurement of
the g-factor of a single, isolated (anti)proton in a
double Penning trap
S. Kreim1, K. Blaum2
,
3, H. Kracke1, A. Mooser1, W. Quint2, C. Rodegheri1, S. Ulmer2
,
4,
J. Walz1
1Institut f¨ur Physik, Johannes Gutenberg-Universit¨at, 55099 Mainz, Germany
2GSI Darmstadt, 64291 Darmstadt, Germany
3Max-Planck-Institut f¨ur Kernphysik, 69117 Heidelberg, Germany
4Ruprecht Karls-Universit¨at, 69047 Heidelberg, Germany
E-Mail: kreim@uni-mainz.de
This experiment is aimed at measuring the magnetic moment or g-factor of a single,
isolated proton stored in a cylindrical Penning trap with a relative uncertainty of 10−9
or better, which will be the first direct measurement of the proton g-factor ever performed.
Determining the g-factor of a particle results from an accurate measurement
of its cyclotron and spin precession frequency. The Larmor frequency can be extracted
by inducing radio-frequency transitions between the two spin states in the homogeneous
magnetic field region of the first, precision Penning trap. The resulting spin state is then
detected non-destructively in the magnetic bottle field of the analysis trap. There, the
magnetic moment is coupled to the axial eigenmotion shifting this frequency according
to the spin direction. The value of the frequency shift scales with the magnetic moment
of the particle and the strength of the magnetic bottle. Thus, a novel trap design was
developed which we call hybrid Penning trap [1] to increase the axial frequency jump to
a detectable range.
To achieve a high-precision determination of the proton g-factor, long storage times are
required which is realized by performing the experiment in a closed setup at 4K yielding
extremely low background pressure (p < 10−16 mbar). This environment bears great challenges
for the electronics needed to non-destructively detect the trapped proton, however,
it leads to a low electronic noise. In addition, the use of superconductive resonant circuits
increases the signal-to-noise ratio of the detection system by some orders of magnitude.
Since the sealed system requires an in-trap creation of protons, a newly developed cryogenic
electron gun [2] will function as an electron beam ion source permitting the creation
of protons inside the magnetic field and at 4 K. Commissioning experiments with electron
gun and fully cabled system will be presented where the performance of the trap tower and
the thermal behavior of electronic components were examined. At present, the detection
circuits are implemented to yield spectra of particle clouds shortly.
Besides the proton g-factor, future experiments aim at determining the antiproton gfactor.
Comparison of the two experimental values will provide a stringent test of CPT
invariance on the baryonic sector. Furthermore, the hybrid trap design enables a variety
of new experiments such as investigating the magnetic moments of bare light nuclei like
3He or tritium.
References
[1] J. Verdu et al., LEAP Conf. Proc., 260 (2005), J. Verdu et al., submitted (2008)
[2] F. Maurer, et al., Nucl. Instr. Meth. B 54, 234 (2005)
CP 123
145
Helium-4 Clusters Doped with Excited Rubidium
Atoms
Robert E. Zillich1, Markku Leino2, Alexandra Viel2
1Institute of Theoretical Physics, Johannes Kepler Universit¨at Linz, Austria
2Institute of Physics of Rennes, UMR 6251 du CNRS, Universit´e de Rennes 1, France
We report on a quantum Monte Carlo study of helium nanodroplets doped with an elec-
tronically excited rubidium atom, Rb . Our work is motivated by recent experiments
conducted in Graz and Freiburg.
The Rb-HeN potential energy surface (PES) is simply a sum of pair potentials if the Rb
is in the electronic ground state. If Rb is in an electronically excited state (Rb ), the PES
of Rb –HeN is based on the diatomics-in-molecules model, thus it is different from a pair
potential. Moreover, the spin-orbit coupling cannot be neglected and it is responsible for
different equilibrium structures when compared with potassium.
We use the diffusion Monte Carlo (DMC) method to obtain ground state energies along
with different unbiased pair distribution densities. For the first excited state of Rb, the
PES could accommodate a planar ring of N = 8 helium atoms, but the DMC simulations
show that only N = 7 atoms fit into the ring, because of the large zero point motion of
He atoms. Adding more atoms creates a very diffuse second ring.
For simulations at the temperature of large 4He droplets of about T = 0.3 − 0.4K, we
employ the path integral Monte Carlo (PIMC) method. If Rb is in the electronic ground
state, Rb-HeN is a weakly bound complex. Increasing N to N = 100 it becomes a He
droplet with Rb sitting in a “dimple” on the surface. For Rb in the first excited state,
PIMC simulations confirm the DMC results, that a ring of up to 7 He atoms forms around
the Rb atom.
In order to model the experiments where Rb is excited from the electronic ground state to
the first excited state, we performed PIMC simulations where we start from equilibrium
configurations of Rb-HeN and then switch to the PES of the 1st excited state. In this
case, we do not find any signature of a He ring around Rb , but instead Rb is promoted
to a very weakly bound, metastable state where it sits in a shallow He dimple. This result
agrees with the interpretation of recent experiments [1]. We used the same modeling for
the excitation from the ground state to the 2nd excited state of Rb. In this case, we
found a clear signature of the formation of a Rb He exciplex, which is weakly bound to
the cluster of N −1 He atoms. We plan to investigate the dynamics upon such electronic
excitations of Rb using correlated basis function theory.
References
[1] W. Ernst et al., private communication
CP 124
146
Progress in optically-detected spin-resonance on
helium droplets
M. Koch, J. Lanzersdorfer, G. Aubock, J. Nagl, C. Callegari, and W. E. Ernst
Institute of Experimental Physics, Graz University of Technology, Graz, Austria
We demonstrate the possibility of optically detecting the spin state of alkali metal atoms
and molecules weakly bound on the surface of helium nanodroplets, immersed in a magnetic
eld. This allows us to show that the electronic spins of atoms do not relax within
the timescale of the experiment ( 10􀀀3 s) and those of molecules do. With this prerequisite
knowledge, we demonstrate that electron spins on a He droplet can be manipulated.
We show why Rb do not desorb from the droplet upon laser excitation, and how this leads
to optical pumping, which we achieve experimentally.
With the addition of a microwave eld, we have just succeeded in optically detecting
an electron-spin transition, on K atoms; the perturbation due to the helium results in a
distinct shift of the g value, which we are in the process of accurately quantifying; the
same measurements will be done on Rb, and the latest results will be presented at the
meeting.
References
[1] J. Nagl, G. Aubock, C. Callegari and W. E. Ernst, Phys. Rev. Lett. 98, 075301 (2007).
[2] G. Aubock, J. Nagl, C. Callegari and W. E. Ernst, J. Phys. Chem. A 111, 7404 (2007).
[3] G. Aubock, J. Nagl, C. Callegari and W. E. Ernst, submitted to Phys. Rev. Lett.
(2008).
CP 125
147
Effect of finite detection efficiency
on the observation of the dipole-dipole interaction
of a few Rydberg atoms
I.I.Ryabtsev, D.B.Tretyakov, I.I.Beterov, and V.M.Entin
Institute of Semiconductor Physics, Pr. Lavrentyeva 13, 630090 Novosibirsk, Russia
E-mail: ryabtsev@isp.nsc.ru
Studies of the long-range interactions in small ensembles of closely placed Rydberg atoms
are important to implement quantum logic gates of a quantum computer. As such gates
imply coherent interactions of two Rydberg atoms, or excitation of only one Rydberg
atom at the dipole blockade, the key issue in these studies is the high detection efficiency
of Rydberg atoms and the need to distinguish between the signals measured for 1, 2, 3,
etc., atoms with high fidelity.
Selective Field Ionization (SFI) technique [1] is most appropriate to detect single Rydberg
atoms. However, microchannel plate detectors commonly used in experiments do not pro-
vide the single-atom resolution. Therefore, in our work we focused on detecting Rydberg
atoms with a channeltron. In our experiments we have found that the histograms of its
output pulses have prominent maxima corresponding to 1-5 detected atoms. Combined
with the post-selection technique, this provides a tool to investigate the signals measured
in experiments on long-range interactions of definite small numbers of Rydberg atoms.
We have developed a simple theoretical model [2] describing multiatom signals that we
measure in the experiments on Stark-tuned resonant dipole-dipole interactions [1] of a few
Rydberg atoms in an atomic beam and frozen Rydberg gas. We have shown that finite
efficiency of the SFI detector leads to the mixing up of the spectra of resonant collisions
registered for various numbers of Rydberg atoms. The formulas are presented, which help
to estimate an appropriate mean Rydberg atom number for a given detection efficiency.
The dependences of the measured signals on the number of atoms, excitation volume,
energy and interaction time were investigated. We have also found that a measurement
of the relationship of the amplitudes of resonances observed in the one- and two-atom
signals provides a straightforward determination of the absolute detection efficiency and
mean Rydberg atom number excited per laser pulse. This method is advantageous as it
is independent of the specific experimental conditions.
Finally, we have performed the testing experiments on resonant dipole-dipole interac-
tions Na(37S)+Na(37S)!Na(36P)+Na(37P) in a small excitation volume of a sodium
atomic beam [2] and Rb(nP)+Rb(nP)!Rb(nS)+Rb((n+1)S) in a rubidium magneto-
optical trap. The resonances obtained for 1 to 5 of detected Rydberg atoms have been
analyzed and compared with the theory. The peculiarities of the obtained results will be
discussed in this report.
This work was supported by the Russian Academy of Sciences.
References
[1] T.F.Gallagher, ”Rydberg Atoms”, Cambridge University Press, Cambridge (1994).
[2] I.I.Ryabtsev, D.B.Tretyakov, I.I.Beterov, and V.M.Entin, Phys. Rev. A, 2007, v.76,
p.012722.
CP 126
148
Energy approach to discharge of metastable nuclei
during negative muon capture
A.V. Glushkov12, O.Yu. Khetselius2, S.V. Malinovskaya2, Yu.V. Dubrovskaya2
1Institute for Spectroscopy of Russian Academy of Sciences, Troitsk, 142090, Russia
2Odessa University, P.O.Box 24a, Odessa-9, 65009
A negative muon captured by a metastable nucleus may accelerate the discharge of the
latter by many orders of magnitude [1]. For a certain relation between the energy range
of the nuclear and muonic levels the discharge may be followed by the ejection of a muon,
which may then participate in the discharge of the other nuclei. We developed new,
QED energy approach (EA) to calculating characteristics for the discharge of a nucleus
with emission of quantum and further muon conversion, which initiates this discharge.
Traditional process of the muon capture are in details studied earlier and here is not
considered. The intensities of satellites (decay probability) are linked with imaginary
part of the "nucleolus core+ proton +muon" system. Three channels should be taken
into account: 1). radiative purely nuclear 2j-poled transition (probability P1; this value
can be calculated on the basis of known traditional formula); 2). Non-radiative decay,
when a proton transits into the ground state and a muon leaves the nuclei with energy
E = E(p ¡ N1J1) ¡ E(i), where E(p ¡ N1J1) is an energy of nuclear transition, E(i)
is an energy of bond for muon in the 1s state (P2); 3). A transition of proton into the
ground state with excitation of muon and emission of the quantum with energy E(p ¡
N1J1) ¡ E(nl) (P3). Under condition E(p-N1J1)>E(i) a probability de¯nition reduces
to QED calculation of probability of the autoionization decay of the two-particle system.
Numerical calculation is carried out for the Sc nucleus. The probabilities of the meso atom
decay for di®erent transitions: P2(p1=2¡p3=2) = 3:93¢1015, P2(p1=2¡f7=2) = 3:15¢1012,
P2(p3=2¡f7=2) = 8:83¢1014. For above indicated transitions the nucleus must transit the
momentum no less than 2,4 and 2 according to the momentum and parity rules. If a meso-
atom is in the initial state p1/2, than the cascade discharge occur with ejection of muon on
the ¯rst stage and the quantum emission on the second stage. To consider a case when the
second channel is closed and the third one is opened, suppose: E(p1=2)¡E(p3=2) = 0:92
MeV. Energy of nuclear transition is not su±cient to transit the muon into the continuum
state and it may excite into the 2p state. In this case there is the proton transition p1/2-
p3/2 with virtual excitation of muon into states of series nd and quantum emission with
energy EE = Ep(p1=2) + E(1s) ¡ Ep(p3=2) ¡ E(2p). The dipole transition 2p-1s occurs
with probability: P3 = 1:9 ¢ 1013 s¡1 that is more than probabilities of the p1/2-p3/2 and
p1/2-f7/2 transitions without radiation.
References
[1] V.I.Gol'dansky, V.S.Letokhov, JETP. 67, 513 (1974); L.N.Ivanov, V.S.Letokhov, JETP.
70, 19 (1976); A. Glushkov, L.N. Ivanov, Phys. Lett.A. 170, 33 (1992)
[2] A. Glushkov et al, Recent Adv. In Theory of Phys. and Chem Systems (Springer).
15, 301 (2006).
[3] A.V.Glushkov, S.V.Malinovskaya, In: New projects and New lines of research in Nu-
clear Phys., eds.Fazio G.,Hanappe F., World Sci.,Singapore, 242 (2003); Nucl. Phys. A.
734, 21 (2004)
CP 127
149
Resonance phenomena in heavy ions collisions and
structurization of positron spectrum
A.V. Glushkov12
1Institute for Spectroscopy of Russian Academy of Sciences, Troitsk, 142090, Russia
2Odessa University, P.O.Box 24a, Odessa-9, 65009
A great interest to this topic has been, in particular, stimulated by inaugurating the
heavy-ion synchrotron storage cooler ring combination SIS/ESR at GSI [1]. The known
discovery of existence of a narrow and unexpected e+ line in the positron spectra obtained
from heavy ions collisions near the Coulomb barrier. Here a consistent uni¯ed QED ap-
proach is developed and applied for studying the low-energy heavy ions collision, including
the electron- positron pair production (EPPP) process too. To calculate the heavy ions
(atoms, nuclei) (EPPP) cross-section we use modi¯ed versions of the relativistic energy
approach, based on the S-matrix Gell-Mann and Low formalism and QED operator per-
turbation theory [2]. The nuclear subsystem and electron subsystem has been considered
as two parts of the complicated system, interacting with each other through the model
potential. The nuclear system dynamics has been treated within the Dirac equation with
e®ective potential. All the spontaneous decay or the new particle (particles) production
processes are excluded in the 0th order. Resonance phenomena in the nuclear system
lead to the structurization of the positron spectrum produced. Analysis of data for cross-
section at di®erent collision energies (non-resonant energies, resonant ones, corresponding
to energies of s-resonances of compound U-Cf, U-U, U+Ta system) is presented. The spe-
cial features are found in the di®erential cross-section for the nuclear subsystem collision
energies, for example, for U-U susyem as follows: (a) E1 = 162.0 keV (3rd s-resonance),
(b) E1 = 247.6 keV (the 4th s-resonance), (c) E1=352,2 keV (5th upper s-resonance).
References
[1] J.Reinhardt, U. Muller, W.Greiner, Z. Phys.A. 303, 173 (1981); V.Zagrebaev, W.Greiner,
J. Phys. G. 34, 1 (2007); V.Zagrebaev, V.Samarin, W.Greiner, Phys.Rev.C. 75,035809
(2007); A.Glushkov, JETP Lett. 55, 95 (1992); Low Energy Antiproton Phys., AIP
Serie. 796, 206 (2005); A.Glushkov, L.Ivanov, Phys.Lett.A. 170, 33 (1992); L.Ivanov,
A.Glushkov etal, Preprint Inst.for Spectroscopy RAS, AS-5, Moscow (1991); L.Ivanov,
T.Zueva, Phys.Scr. 43, 374(1991).
[2] A. Glushkov, et al, J. Phys. CS. 11, 188 (2004); 11, 199 (2004); 35, 420 (2005);
Int.J.Quant.Chem. 104, 512 (2005); 104, 562 (2005).
CP 128
150
Dynamics of the resonant levels for atomic and
nuclear ensembles in a laser pulse: optical bi-stability
e®ect and nuclear quantum optics
O.Yu. Khetselius
Odessa University, P.O.Box 24a, Odessa-9, 65009, Ukraine
Present paper has for an object (i) to carry out numerical quantum computation of a tem-
poral dynamics of populations di®erences at the resonant levels of atoms in a large-density
medium in a non-rectangular form laser pulse and (ii) to determine possibilities that fea-
tures of the e®ect of internal optical bi-stability at the adiabatically slow modi¯cation of
e®ective ¯led intensity appear in the sought dynamics. It is known that the dipole-dipole
interaction of atoms in dense resonant mediums causes the internal optical bi-stability at
the adiabatically slow modi¯cation of radiation intensity. The experimental discovery of
bistable co-operative luminescence in some matters, in crystal of Cs3Y2Br9Y b3+ particu-
larly, showed that an ensemble of resonant atoms with high density can manifest the e®ect
of optical bi-stability in the ¯eld of strong laser emission. The Z-shaped e®ect is actually
caused by the ¯rst-type phase transfer. On basis of the modi¯ed Bloch equations, we sim-
ulate numerically a temporal dynamics of populations di®erences at the resonant levels of
atoms in the ¯eld of pulse with the non-rectangular ch form. Furthermore, we compare
our outcomes with the similar results, where there are considered the interaction between
the ensemble of high-density atoms and the rectangularly- and sinusoidally-shaped pulses.
The modi¯ed Bloch equations describe the interaction of resonance radiation with the en-
semble of two-layer atoms taking into account the dipole-dipole interaction of atoms [1].
A fundamental aspect lies in the advanced possibility that features of the e®ect of inter-
nal optical bi-stability at the adiabatically slow modi¯cation of e®ective ¯led intensity for
pulse of ch form, in contrast to the pulses of rectangular form, appear in the temporal
dynamics of populations' di®erences at the resonant levels of atoms. Modelling nuclear
ensembles in a super strong laser ¯eld provides opening the ¯eld of nuclear quantum optics
[2,3].
References
[1] A. Glushkov, O. Khetselius et al, J. Phys.CS. 35, 420 (2006)
[2] A. Glushkov, O. Khetselius, Recent Adv. in Theory of Phys. and Chem. Syst.
(Springer). 18 (2008)
[3] A. Glushkov, O. Khetselius, S. Malinovskaya, Europ. Phys. Journ. 32 (2008)
CP 129
151
Spectroscopy of the hadronic atoms and superheavy
ions: Spectra, energy shifts and widths, hyper¯ne
structure
A.V. Glushkov12, O.Yu. Khetselius2, E.P. Gurnitskaya2, Yu.V. Dubrovskaya2,,
D.E.Sukharev2
1Institute for Spectroscopy of Russian Academy of Sciences, Troitsk, 142090, Russia
2Odessa University, P.O.Box 24a, Odessa-9, 65009
Paper is devoted to calculation of the spectra, radiative corrections, hyper¯ne structure
parameters for exotic hadronic atoms and heavy ions with account of the de¯nite nu-
cleus structure modelling. One of the main purposes is establishment a quantitative link
between quality of the nucleus structure modelling and accuracy of calculating energy
and spectral properties of systems. We apply our numerical code [1,2] to calculating
spectra of the hadronic (pion, kaon, hyperon) atoms. A new, highly exact, ab initio ap-
proach [2] to relativistic calculation of the spectra for superheavy ions with an account
of relativistic, correlation, nuclear, radiative e®ects on the basis of gauge-invariant QED
perturbation theory is used. Zeroth approximation is generated by the e®ective ab initio
model functional, constructed on the basis of the comprehensive gauge invariance proce-
dure [2]). The wave functions zeroth basis is found from the Klein-Gordon (pion atom)
or Dirac (kaon, hyperon) equation. The potential includes the core ab initio potential,
the electric and polarization potentials of a nucleus (the Fermi model, the gaussian form
of charge distribution in the nucleus and the uniformly charged sphere are considered).
For low orbits there are important e®ects due to the strong hadron-nuclear interaction
(pion atom). The energy shift is connected with length of the hadron-nuclear scattering
(scattering amplitude under zeroth energy). For superheavy ions the correlation correc-
tions of high orders are accounted within the Green functions method. The magnetic
inter-electron interaction is accounted in the lowest order, the Lamb shift polarization
part- in the Uhling-Serber approximation, self-energy part - within the Green functions
method. We carried out calculations :1).energy levels, hfs parameters for superheavy H
and Li-like ions for di®erent models of charge distribution in a nucleus and super heavy
atom Z=114; 3). Shifts and widths of transitions (2p-1s,3d-2p, 4f-3d) in some pionic and
kaonic atoms (18O, 24Mg etc.) and also K{4He [3].
References
[1] A. Glushkov, L.N. Ivanov, Phys. Lett.A. 170, 33 (1992)
[2] A. Glushkov, et al, J. Phys. CS. 11, 188 (2004); 11, 199 (2004); 35, 420 (2005);
Int.J.Quant.Chem. 104, 512 (2005); 104, 562 (2005).
[3] A. Glushkov, O. Khetselius, S. Malinovskaya, Mol. Phys. 24 (2008); A. Glushkov, O.
Khetselius, Recent Adv. in Theory of Phys. and Chem. Syst. (Springer). 18 (2008);
EUrop. Phys. Journ. (2008).
CP 130
152
CP 131
153
Radiative data in the Zr I spectrum
G. Malcheva1, K. Blagoev1, R. Mayo2, M. Ortiz2, J. Ruiz2, L. Engstr¨om3, H. Lundberg3,
S. Svanberg3, H. Nilsson4, P. Quinet5
,
6 and ´E. Bi´emont5
,
6
1Institute of Solid State Physics, 72 Tzarigradsko Chaussee,BG - 1784 Sofia, Bulgaria
2Department of Atomic, Molecular and Nuclear Physics, Univ. Complutense de Madrid,
E-28040 Madrid, Spain
3Department of Physics, Lund Institute of Technology, P.O. Box 118, S-221 00 Lund,
Sweden
4Lund Observatory P.O. Box 43, S-221 00 Lund, Sweden
5IPNAS (Bt. B15), University of Lige, Sart Tilman, B-4000 Lige, Belgium
6 Astrophysics and Spectroscopy, University of Mons-Hainaut, B-7000 Mons, Belgium
E-mail: bobcheva@issp.bas.bg
Radiative data in the Zr I spectrum, in particular radiative lifetimes of excited states and
transition probabilities of electric dipole (E1) transitions, are of interest for the determination
of the Zr abundance in stars, including the Sun. These data are also important for
the investigation of plasmas, particularly the plasmas near the walls in high-temperature
devices.
In the present work radiative lifetimes for 17 levels belonging to the odd 4d25s5p configuration
are reported. They were measured using a time-resolved laser-induced fluorescence
(TRLIF) technique [1]. The levels investigated are: y3S1; u3P0
,
1
,
2; v3P1
,
2; t3P1; t3D1
,
2
,
3;
u3F2
,
3
,
4; x3G5 and w3G3
,
4
,
5. A single-step laser- excitation process, either from the ground
state or from appropriate metastable states, was used.
Free zirconium atoms were generated by laser ablation in a vacuum chamber with 10−6-
10−5 mbar background pressure. For the ablation, an Nd:YAG laser with 10 ns pulse
duration was used. The laser system for the excitation of the Zr I levels consisted of a
dye laser which had a pulse duration of about 1-2 ns.
For 14 of the investigated states, radiative lifetimes were obtained for the first time. The
error bars are in the interval 4-10%. Measurements of branching fractions are also in
progress by means of the Laser Induced Breakdown Spectroscopy (LIBS) technique.
The relativistic Hartree-Fock (HFR) method, as described by Cowan [2], has been used
to compute radiative lifetimes and transition probabilities and the results are compared
with the experimental data. In the calculations, core-polarization effects and extensive
configuration interaction effects have been taken into account.
This work was financially supported by the Swedish Research Council; by the EU-TMR
access to Large-Scale Facility Programme (contract RII3-CT-2003-506350) and by the
National Science Fundation of Bulgaria (grant 1516/05).
References
[1] Z. G. Zhang, S. Svanberg, P. Quinet, P. Palmeri and ´E. Bi´emont, Phys. Rev. Lett.
87, 273001 (2001)
[2] R. D. Cowan, ”The Theory of atomic Structure and Spectra” (University of California
Press, Berkley, California, USA, 1981)
CP 132
154
Energy levels, oscillator strengths and lifetimes in
Cl IV
G. P. Gupta
Department of Physics, S. D. (Postgraduate) College, Muzaffarnagar 251 001,
(Affiliated to Chowdhary Charan Singh University, Meerut - 250 004), INDIA
E-mail: g p gupta1@yahoo.co.in
Emission lines due to allowed and intercombination transitions in multiply charged Silike
ions are observed in solar corona and laser produced plasma. The lines arises from
intercombination transitions have been shown to be very useful, for instant, in understanding
density fluctuations and elementary processes which occur in both interstellar
and laboratory plasma and the determination of transition energies, oscillator strengths
and transition probabilities of these lines as needed for a qualitative analysis of the spectra
are not well known. This is mainly because these weak lines are usually sensitive to the
theoretical modeling and have been a challenge for the atomic structure theory.
We have calculated the excitation energies, oscillator strengths and transition probabilities
for electric-dipole-allowed and intercombination transitions among the fine-structure
levels of the terms belonging to the configurations (1s22s22p6)3s23p2, 3s3p3, 3s23p3d,
3p4, 3s23p4s, 3s23p4p, 3s3p2(2S)4s, 3s3p2(2P)4s, 3s3p2(4P)4s, 3s3p2(2D)4s, 3s23p4d and
3s23p4f of Si-like Clorine, using extensive configuration-interaction (CI) wavefunctions
[1]. The relativistic effects in intermediate coupling are incorporated by means of the
Breit-Pauli Hamiltonian [2]. Small adjustments to the diagonal elements of the Hamiltonian
matrices have been made so that the energy splittings are as close as possible to the
experiment. From our radiative rates, we have also calculated the radiative lifetimes of
the levels. In this calculation we have investigated the effects of electron correlations on
our calculated data, particularly on the intercombination transitions, by including orbitals
with up to n=5 quantum number. We considered up to two electron excitations from the
valence electrons of the basic configurations and included large number of configurations.
These configurations represent all major internal, semi-internal and all-external electron
correlation effects [3].
The mixing among several fine-structure levels is found to be very strong. These levels are
identified by their eigen-vector composition [4]. The energy splitting of 85 fine-structure
levels, oscillator strengths, transition probabilities for electric-dipole-allowed and intercombination
transitions and the lifetimes of several fine-structure levels are presented and
compared with available experimental levels and the other theoretical results. Significant
differences between our calculated and the other sophisticated theoretical lifetimes for
several fine-structure levels are discussed.
References
[1] A. Hibbert, Comput. Phys. Commun. 9, 141 (1975)
[2] R. Glass, A. Hibbert, Comput. Phys. Commun. 16, 19 (1978)
[3] I. Oksuz, O. Sinanoglu, Phys. Rev. 181, 42 (1969)
[4] G. P. Gupta, K. M. Aggarwal, A. Z. Msezane, Phys. Rev. A70, 036501 (2004)
CP 133
155
Large scale CIV3 calculations of fine-structure
energy levels and lifetimes in Al-like copper
G. P. Gupta1 and A. Z. Msezane2
1Department of Physics, S. D. (Postgraduate) College, Muzaffarnagar 251 001,
(Affiliated to Chowdhary Charan Singh University, Meerut - 250 004), INDIA
2Department of Physics and Center for Theoretical Studies of Physical Systems,
Clark Atlanta University, Atlanta, Georgia 30314, USA
E-mail: g p gupta1@yahoo.co.in
We have performed large scale CIV3 calculations of excitation energies from ground states
for fine-structure levels as well as of oscillator strengths and radiative decay rates for all
electric-dipole-allowed and intercombination transitions among the fine-structure levels
of the terms belonging to the configurations (1s22s22p6)3s23p, 3s3p2, 3s23d, 3p3, 3s3p3d,
3p23d, 3s3d2, 3p3d2, 3s24s, 3s24p, 3s24d, 3s24f, and 3s3p4s of Cu XVII, using very extensive
configuration-interaction (CI) wave functions [1]. The important relativistic effects
in intermediate coupling are incorporated by means of the Breit-Pauli Hamiltonian which
consists of the non-relativistic term plus the one-body mass correction, Darwin term, and
spin-orbit, spin-other-orbit, and spin-spin operators [2]. The errors, which often occur
with sophisticated ab initio atomic structure calculations, are reduced to a manageable
magnitude by adjusting the diagonal elements of the Hamiltonian matrices. In this calculation
we have investigated the effects of electron correlations on our calculated data,
particularly on the intercombination transitions, by including orbitals with up to n=5
quantum number. We considered up to three electron excitations from the valence electrons
of the basic configurations and included large number of configurations (1164) to
ensure convergence.
Our adjusted excitation energies, including their ordering, are in excellent agreement
with the available experimental results [3]. The enormous mixing among several finestructure
levels makes it very difficult to identify them correctly. Perhaps, that may
be the reason for the lack of experimental results for these levels. We believe that our
extensive calculated values can guide experimentalists identify the fine-structure levels
[4]. From our radiative decay rates, we have also calculated radiative lifetimes of the finestructure
levels in Cu XVII. Our calculated lifetimes for the levels 3s3p2(4P) are found to
be in excellent agreement with the experimental results of Trabert et al. [5] compared to
other available theoretical results. We predict new data for several levels where no other
theoretical and/or experimental results are available.
References
[1] A. Hibbert, Comput. Phys. Commun. 9, 141 (1975)
[2] R. Glass, A. Hibbert, Comput. Phys. Commun. 16, 19 (1978)
[3] T. Shirai et al., J. Phys. Chem. Ref. Data 20, 12 (1991)
[4] G. P. Gupta, K. M. Aggarwal, A. Z. Msezane, Phys. Rev. A70, 036501 (2004)
[5] E. Trabert et al., J. Opt. Soc. Am. B5, 2173 (1988)
CP 134
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Levels energies, oscillator strengths, and lifetimes for
transition in Pb III
C. Col´on1, A. Alonso-Medina1, A. Zan´on2 and J. Alb´eniz3
1Dpto. de F´ısica Aplicada, EUITI, Universidad Polit´ecnica de Madrid (UPM), Spain
2Dpto. de Matem´atica Aplicada, EUITI, UPM Madrid, Spain
3Dpto. de Qu´ımica Industrial y Pol´ımeros, EUITI, UPM Madrid, Spain
E-mail: cristobal.colon@upm.es
Information about the oscillator strengths and lifetimes has applications in many scientific
fields. Data about atomic properties are relevant not only to spectroscopy, as these
values are also of interest in a variety of other fields in physics and technology. In astrophysical
applications this information can be used to determine elemental abundances
from absorption spectra. These data are also essential to calculate the Stark width and
shift parameters of spectral lines. In previous work [1-3] we have measured and calculated
experimental an theoretical values for Pb III.
Transition Probabilities and oscillator strengths for several lines of astrophysical interest
arising from 5d96s26p, 5d106snl, 5d106s2, 5d106p2, 5d106p7s, and 5d106p6d configurations
and some levels radiative lifetimes of Pb III has been calculated. These values were
obtained in intermediate coupling (IC) and using ab initio relativistic Hartree-Fock calculations.
We use for the IC calculations the standard method of least square fitting of
experimental energy levels by means of computer codes from Cowan (1981). The inclusion
in these calculations of the 5d106p7s and 5d106p6d configurations has facilitated us
a complete assignment of the levels of energy of the Pb III. The system considered is
complex, with high Z were both relativistic and correlation effects must be important.
Least-square fitting of experimental energy levels partially account correlation effects not
explicitly calculated in our work. Nevertheless and as we already waited, there are some
noticeable discrepancies between our theoretical values and experimental data of oscillator
strengths and lifetimes for the resonance lines 1048.9 and 1553.0 °A. These discrepancies
have been studied with detail in the bibliography and we think that they can be corrected
with the inclusion of core polarization effects. Oscillator strengths and radiative lifetimes
obtained, although in general agreement with the rare experimental data [see e.g. 4-7],
do present some noticeable discrepancies, that are studied in the text.
References
[1] A. Alonso-Medina ,C. Col´on , A. Zan´on, MNRAS 385, 261 (2008).
[2] C. Col´on, A. Alonso-Medina, C. Herr´an-Mart´ınez , J. Phys. B: Atom. Mol.Opt. Phys.
32, 3887 (1999).
[3] C. Col´on, A. Alonso-Medina, Physica Scripta 62, 132 (2000).
[4] T. Andersen , A. Kirkegard Nielsen, G. Sorensen G., Physica Scripta 6,122 (1972).
[5] W. Ansbacher, E. H. Pinnington, J. A. Kernahan, Can. J. Phys. 66, 402 (1988).
[6] H. -S. Chou, K. -N. Huang K, Chin. J. Phys 35, 35 (1997).
[7] L. J. Curtis et al., Physical Review A 63, 042502 (2001).
This work has been supported by the project CCG07-UPM/ESP-1632 of the UPM. IV
PRICIT of the CAM (Comunidad Aut´onoma de Madrid), SPAIN.
CP 135
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CP 136
158
Einstein coe±cients for activation barriers of
equilibrium and non-equilibrium processes caused by
Plank radiation
A. Stepanov
Byelorussian State University, National Ozone Monitoring Research and Educational
Centre, 7-816 Kurchatov Street, 220064 Minsk, Republic of Belarus, E-mail:
stepav@bsu.by
Analytical calculation of Einstein coe±cients is made for activation barrier of the Boltzmann-
Arrhenius model and an activation process model. For the activation process model an
activation barrier is shown to have discrete energy structure due to its thermodynamic
equilibrium with thermal radiation. This structure is determined by interaction of confor-
mation substates of a molecule with thermal radiation. The Boltzmann-Arrhenius model
represents an activation process as a result of the work of high-energy spectral components
of thermal equilibrium radiation. The process is realized by overcoming a potential barrier
with continuous energy structure. However, it is shown, that such process is essentially
non-equilibrium and hard to achieve at thermal equilibrium radiation [1].
References
[1] A. V. Stepanov, J. Mol. Struct.:THEOCHEM 805, 87 (2007)
CP 137
159
New transition probabilities of astrophysical interest
in triply ionized lanthanum (La IV)
V. Fivet1, ´E. Bi´emont1,2, P. Palmeri1 and P. Quinet1,2
1 Astrophysique et Spectroscopie, Universit´e de Mons-Hainaut, B-7000 Mons, Belgium
2 IPNAS, Universit´e de Li`ege, Sart Tilman, B-4000 Li`ege, Belgium
E-mail: vanessa.fivet@umh.ac.be
Despite their low cosmic abundances, the lanthanides (Z=57-71) become increasingly
important in astrophysics because they are strongly enhanced in some chemically peculiar
(CP) stars. Up to now, triply ionized lanthanides have not been investigated in stellar
spectra, the main reason being the lack of atomic data. According to Saha equation
however, these ions are expected to be observed in hot-stars spectra. The main purpose
of the present work is to fill in this gap and to provide the astrophysicists with the radiative
data they need for a quantitative investigation of CP-stars high-resolution spectra.
During the meeting, we will present preliminary results obtained so far for triply ionized
lanthanum (La IV). The accuracy of the new data will be assessed through comparison
of the results obtained within the framework of two independent theoretical approaches,
i.e. the partly relativistic Hartree-Fock method [1] and the fully relativistic multiconfigurationnal
Dirac-Fock approach [2]. Homologous lighter ions will also be considered for
testing the adopted model.
The present work on La IV is a continuation of a long-term effort carried out at Mons
University in order to improve the radiative data of the rare-earth (RE) elements in their
first ionization degrees. Results obtained previously for many RE atoms and ions are
stored in the database DREAM on a web site of Mons University, Belgium (See [3] and
the references therein).
References
[1] R.D. Cowan, The Theory of Atomic Structure and Spectra, University of California
Press, Berkeley (1981)
[2] I.P. Grant, Relativistic Quantum Theory of Atoms and molecules, Springer-Verlag,
New York (2007)
[3] http://www.umh.ac.be/ astro/dream.shtml
CP 138
160
A new method for determining minute long lifetimes
of metastable levels
J. Gurell1, P. Lundin1, S. Mannervik1, L.-O. Norlin2 and P. Royen1
1Department of Physics, Stockholm University, AlbaNova University Center, SE-10691
Stockholm, Sweden
2Department of Physics, Royal Institute of Technology, AlbaNova University Center,
SE-10691 Stockholm, Sweden
Radiative lifetime measurements of metastable states have been performed for many years
utilizing stored ions. When measuring lifetimes of metastable states in a storage ring the
signal may be greatly enhanced, compared to that from passive observation, by actively
inducing transitions with one or more lasers. The basic principle of our laser probing
technique has been to probe the population of the metastable state as a function of delay
time after ion injection which gives us a population decay curve, see e.g. Ref. [1]. The
introduction of lasers also increases the maximum possible measurable lifetime signi¯-
cantly. Currently the longest radiative lifetime measured at the storage ring CRYRING
in Stockholm, Sweden, and to the best of our knowledge in storage rings in general, is
89 s in BaII, see Ref. [2]. For lifetimes longer than this collisional excitation of stored
ground state ions becomes a problem since after a few seconds of storage the vast majority
of the population of the metastable state under study will be originating from ions that
were in the ground state when injected into the storage ring. During the analysis, this
contribution is subtracted from the total °uorescence which gives a low S/N ratio, large
uncertainties and eventually limits the maximum possible lifetime measurable.
A new method has therefore been proposed and its advantages concerning more accurate
lifetime determinations of extremely long lived metastable states demonstrated, see Ref.
[3]. Instead of monitoring the decay of the population of the metastable state relative to
ion injection the contribution from collisional excitation is monitored directly. In contrast
to the metastable state population itself, the collisional excitation grows stronger with
increased storage time which results in a much higher S/N ratio at longer storage times
and higher residual gas pressures and as a consequence the maximum possible radiative
lifetime measurable increases. This technique has so far only been applied in two studies
with lifetimes ranging from 16 to 32 s, the 5d 2D5=2 state in BaII, see Ref. [3], and the
b 4P5=2 state in TiII, submitted to J Phys B. This new technique has not yet been pushed
to its limit but lifetimes of a few minutes will most probably be possible to measure.
References
[1] P. Lundin, J. Gurell, L.-O. Norlin, P. Royen, S. Mannervik, P. Palmeri, P. Quinet,
V. Fivet and ¶E. Bi¶emont PRL 99 213001 (2007)
[2] J. Gurell, E. Bi¶emont, K. Blagoev, V. Fivet, P. Lundin, S. Mannervik, L.-O. Norlin,
P. Quinet, D. Rostohar, P. Royen and P. Schef PRA 75 052506 (2007)
[3] P. Royen, J. Gurell, P. Lundin, L.-O. Norlin and S. Mannervik PRA 76 030502(R)
(2007)
CP 139
161
Lifetime measurements of metastable states of
astrophysical interest
J. Gurell1, P. Lundin1, S. Mannervik1, L.-O. Norlin2, P. Royen1, P. Schef1, H. Hartman3,
A. Hibbert4, H. Lundberg5, K. Blagoev6, P. Palmeri7, P. Quinet7;8 and ¶E. Bi¶emont7;8
1Department of Physics, Stockholm University, AlbaNova University Center, SE-10691
Stockholm, Sweden
2Department of Physics, Royal Institute of Technology, AlbaNova University Center,
SE-10691 Stockholm, Sweden
3Lund Observatory, Lund University, Box 43, 22100 Lund, Sweden
4Department of Applied Mathematical and Theoretical Physics, Queen's University,
Belfast BT7 1NN, Northern Ireland
5Department of Physics, Lund Institute of Technology, Box 118, 22100 Lund, Sweden
6Institute of Solid State Physics, Bulgarian Acad. of Sciences, 72 Tzarigradsko
Chaussee, BG-1784 So¯a, Bulgaria
7Astrophysique et Spectroscopie, Universit¶e de Mons-Hainaut, B-7000 Mons, Belgium
8IPNAS, Universit¶e de Liµege, Sart Tilman B15, B-4000 Liµege, Belgium
Under normal laboratory conditions metastable states are commonly depleted through
collisions between particles. Under astrophysical conditions, however, low pressures and
temperatures can make the mean free path of particles so long that ions in metastable
states have time to decay spontaneously through forbidden transitions which are usually
not observed in laboratory light sources. Since the intensity of these forbidden lines are
strongly dependent on the frequency of particle collisions these transitions may be used
as density probes of dilute astrophysical plasmas.
The super massive star ´ Carinae has attracted much attention recently. One of the
surrounding regions referred to as the Strontium-¯lament contains ejecta from ´ Carinae
and shows a number of forbidden lines from Sr II, Fe I, Ti II and Sc II. In order to use
these lines as probes transition probabilities are needed which are either calculated or
measured indirectly through lifetime measurements in combination with experimental
branching fractions.
At the storage ring CRYRING in Stockholm, Sweden, lifetime measurements of metastable
states have been performed for many years (see e.g. Ref. [1]) and recently lifetimes of
metastable levels in Sc II and Ti II have been measured and submitted for publication
together with new calculations. The experimental technique utilizes a laser probing tech-
nique and the resulting lifetimes are used in combination with astrophysical branching
fractions deduced from spectra recorded with the STIS spectrograph on board the Hubble
Space Telescope, see e.g. Ref. [2]. All measurements, which are ranging from 1-24 s, are
complemented by theoretical calculations showing good agreement with the experimental
values.
References
[1] S. Mannervik, A. Ellmann, P. Lundin, L.-O. Norlin, D. Rostohar, P. Royen and P.
Schef Phys. Scr. T119 49 (2005)
[2] H. Hartman et al. A&A 397 1143 (2003)
CP 140
162
Spin-exchange e ects in elastic electron scattering
from linear triatomic radicals
M.-T. Lee1, M. M. Fujimoto2, S. E. Michelin3, and I. Iga1
1 Departamento de Qu mica, UFSCar, 13565-905, S~ao Carlos, SP, Brazil
2 Departamento de F sica, UFPR, 81531-990 Curitiba, PR, Brazil
3 Departamento de F sica, UFSC, 88040-900 Florian opolis, SC, Brazil
E-mail: dlmt@ufscar.br
Low-energy electron collisions with atoms, molecules, radicals, and surfaces are, in general,
strongly in uenced by electron-exchange e ects. Such e ects can be easily characterized in
the electron-impact spin-forbidden excitations (for instance, singlet-to-triplet transitions).
Although exchange mechanism is also important in low-energy elastic electron-molecule
collisions, its e ects is usually masked since most experimental studies are performed using
unpolarized electron sources and without spin analysis of the scattered beam. Limited
experimental studies have been reported in the literature over the past years. For instance,
spin- ip (SF) di erential cross sections (DCSs) for elastic electron scattering by the Na and
Hg atoms as well as by the open-shell O2 and NO molecules were reported by Hegemann
et al. [1]. Although signi cant spin-exchange e ects were found for atomic targets, very
small e ects were observed for O2 and NO. Lately, theoretical studies of da Paix~ao et
al. [2] have shown that the almost isotropic polarization fractions (SPFs) of scattered
electrons is mainly caused by the molecular orientation averaging, since gaseous targets
are randomly oriented in space.
Recently, we reported a theoretical investigation on spin-exchange e ects in elastic electron
collisions with the open-shell C2O radical [3] using the iterative Schwinger variational
method (ISVM). In that study, we have shown that the exchange e ects are strongly enhanced
by the occurrence of resonances. In this sense, the calculated P0/P averaged over
all orientations are no longer isotropic and deviate signi cantly from unity particularly at
large scattering angles.
Here, we extend the spin-exchange study to two linear triatomic open-shell molecules,
namely CNN and NCN. These two targets are isoelectronic of C2O radical with the
ground-state electronic con guration X3 􀀀. As in C2O, strong shape resonances are also
present in the doublet- and quartet-coupling scattering channels for both targets in the
low-incident energy range [3]. In this work, we report a calculation of spin- ip (SF)
di erential (DCSs) and integral cross sections (ICSs) as well as spin-polarization (SPFs)
fractions for elastic electron scattering by CNN and NCN in the (1-10)-eV energy range.
Our calculated SF DCSs and SPFs as well as the SF ICSs for these two targets will be
presented during the EGAS.
This work is partially suported by the Brazilian agency CNPq.
[1] T. Hegemann, M. Oberste-Vorth, R. Vogts, and G. F. Hanne, Phys. Rev. Lett. 66
2968 (1991).
[2] F. J. da Paix~ao, M. A. P. Lima, and V. McKoy, Phys. Rev. A 53 1400 (1996).
[3] M. M. Fujimoto, S. E. Michelin, I. Iga, and M.-T. Lee, Phys. Rev. A 73 012714
(2006).
CP 141
163
Spectral properties of interactions in metallic
endohedral fullerenes Li2@C60 and Na2@C60
Zapryagaev S.A., Butyrskaya E.V.
Voronezh State University. Russia
Endohedral fullerenes are of great interest due to their diversity applications as in technology
so in fundamental research of interatomic interactions. Because of the robust carbon
cage and its large hollow interior space fullerenes can be used as molecular containers and
as building blocks of carbon-based nanotechnology. The program Gaussian 03 and HF
method in basis 3-21G was used in calculation at present work to investigate a spectral
properties of an interactions of Li2 and Na2 molecules encapsulated in C60 carbon cage
that are produced endohedral metallic fullerenes Li2@C60 and Na2@C60. Encapsulating
molecules inside fullerene C60 changes a structure and properties, both molecules as a
carbon skeleton. According of Mulliken population data significant carry of electronic
density from an encapsulated molecule on fullerene cage is observed. Except according
of presented calculation a compression of encapsulated Na2 molecule takes place. This
compression is consequence of steric interaction of multielectronic Na2 system from a
carbon cage. This effect is not observed at encapsulate inside C60 Li2 molecule having
the smaller sizes then Na2 molecule. On the contrary the internuclear Li−Li distance increases,
in comparison with free two-nuclear molecule Li2 that shows an increase Mulliken
charge atoms of lithium inside fullerene.
Redistribution of electronic density changes a picture of an oscillatory spectrum of the visitor’s
molecule and the fullerene too. The analysis of the form of oscillations for metallic
fullerenes has shown, that all normal oscillations can be divided on two groups: - 6 oscillations
in which atoms of metal take part and 174 oscillations of a carbon skeleton. Except
of metallic atoms oscillation near balance position, oscillation of a metallic molecule as
a whole inside fullerene and antiphase oscillations of atoms of an encapsulated molecule
perpendicularly to nuclear line take place.
Frequencies of normal oscillations of encapsulated molecules Li2 and Na2 according to calculation
are equal: 67, 93, 117, 145, 263 , 290 cm−1 for Li2 and 9, 24, 63, 81, 209, 354 cm−1
for Na2. The symbol notes the frequencies of nuclear oscillations near the balance position,
equal for the main electronic term X1 +
g of two-nuclear molecules Li2 and Na2
accordingly 352 cm−1 and 159 cm−1. The fullerene spectrum according to downturn
of system symmetry also changes: instead of 4 active in C60 IR modes the number of
absorption bands in a fullerene spectrum increases. Optimization of metallic fullerenes
structures and the calculation of IR spectra is executed for a case when metals are located
on an C2 axis of symmetry, and atoms of carbon in C60 are fixed and for a case of full
optimization without the requirement of preservation of symmetry. For the case when
atoms of metal are located on C2 axis, reference of fullerene cage oscillation according to
a new system symmetry is executed.
CP 142
164
Simulation of fullerene formation
Zapryagaev S.A., Butyrskaya E.V.
Voronezh State University. Russia
The reason why C60 is by far the most abundant fullerene in carbon soot still remains
unrevealed/ It is well known, that C60 fullerene is not energetically the most stable cluster
among that clusters can be find in soot. For example C70 and C84 have larger binding
energies per atom than C60. Hence C60 should be less stable energetically than some other
fullerenes. Nevertheless, C70 is the second most abundant and C84 the third. Besides, the
production yields of them are much lower than of C60. These facts imply the unimportance
of binding energy for the production fullerenes. To elucidate a reason why C60 is the most
abundant one need to unveil the process of fullerenes formation.
There are some formation models - ”pentagon road”, ”fullerene road”, ”ring stacking
model” and ”C10” reaction road. Pentagon road model bases on the curling of graphitic
sheets through the incorporation of pentagons forms fullerenes. Fullerene road model
assumes that the small fullerenes grow into lager ones through sequential C2 additions.
Ring stacking assumes that fullerenes are formed by sequential stacking of carbon rings. It
is natural to expect that the C atoms react with each other to form small carbon clusters
in the early stage of fullerene formation process. That is why the study of small carbon
cluster is the important stage of fullerene formation.
At present work we optimize the ground -state geometries of small carbon clusters using
the b3lyp method of Gaussian 03 program and simulate the fullerene formation according
the ”C10” reaction road method proposed in [1]
References
[1] Yusuke Ueno and Susumu Saito, Phys Rev. B77, 085403 (2008)
CP 143
165
CROSS SECTIONS OF NEGATIVE ION PRODUCTION IN ELECTRON COLLISIONS
WITH ADENINE MOLECULES
I.I.Shafranyosh, M.I.Sukhoviya, M.I.Shafranyosh, Fedorko R. O.
Department of Physics, Uzhgorod National University, Uzhgorod 88000, Ukraine
We report absolute cross sections for the
formation negative ions resulting from electron
interactions with adenine. Interest in
experimental studies of the processes of electronimpact
ion production in the molecules of
biological relevance is related, first of all, to the
significance of the problem of intracellular
irradiation of biological structures by secondary
electrons produced in the substance in quite
considerable amounts under the influence of
different-type radiation. It has been shown in our
preliminary experiments carried out with the
heterocyclic components of the above molecules
[1–2] that under electron impact different
physical processes occur: i.e. molecules
excitation, ionization, dissociative excitation and
dissociative ionization. Physical modeling of
these processes and estimation of their
radiobiological consequences require knowledge
of their basic characteristics – absolute ionization
cross sections. Reliable data on the ionization
cross sections could be obtained only in the
precise experiment, in which the role of
environment is minimized. Such approach was
applied in this work.
Production of negative ions of adenine
molecules (nucleic acid base) has been studied
using a crossed electron and molecular beam
technique. The method developed by the authors
enabled the molecular beam intensity to be
measured and the electron dependences and the
absolute values of the total cross sections of
production of negative adenine ions to be
determined. A five-electrode electron gun with a
thoriated tungsten cathode was used as an
electron beam source. Electron gun temperature
was about 400K providing gun parameter
stability during operation. Electrons having
passed the interaction region were trapped by a
Faraday cup kept at the positive potential.
Measurements were carried out at the 10-7–10-6 A
electron beam current and the ΔE1/2~0.3 eV
(FWHM) energy spread. Electron gun was
immersed into the longitudinal magnetic field
(induction B = 1.2⋅102 Tl). An electron energy
scale was calibrated with respect to the resonance
peak of the SF6
– ion production, the position of
which determined the zero point of the energy
scale.
Using the technique developed by the authors,
the absolute cross sections of the negative
adenine ions formation have been determined for
electron energy in the interval from 0.4 to 5.0
eV. It has been found that the maximal negativeion
formation cross section σ = 6⋅10-18 cm2 was
observed for an electron energy of 1.2 eV . Main
contribution to the cross section was shown to
result from the dissociative ionization cross
section. It has been noted that due to the
resonance mechanism of the negative adenine
ions formation just at low incident electron
energy considerable disorders in the nucleic acid
macromolecules are probable.
References
[1] Sukhoviya M.I., Slavik V.N., Shafranyosh
I.I.. Biopolym. Cell. 7, 77 (1991) (in
Russian).
[2] Sukhoviya M.I., Shafranyosh M.I.,
Shafranyosh I.I. Spectroscopy of Biological
Molecules: New Directions (Kluwer Acad.
Publ.-Dordrecht /Boston /London) p.281
(1999).
CP 144
166
CP 145
167
Anomalous inhomogeneous broadening and kinetics
properites of DMABN
K. Hubisz, T. Wr oblewski, V.I. Tomin
Institute of Physics, Pomeranian University,
76-200 S lupsk, Arciszewskiego 22B, Poland.
E-mail: tomin@apsl.edu.pl
The anomalously large spectral inhomogeneity of the electronic bands ( 145 nm)
of N, N-dimethylaminobenzonitrile (DMABN) in a polar solution of glycerol has been
found and investigated [1,2]. In nonpolar solutions there is no substantial manifestation
of inhomogeneous broadening.
In addition to the local excited (LE) band ( 360 nm), the emission spectra distinctly
display the band associated with internal change transfer, the CT band having a maximum
near 460 nm. The most interesting property of spontaneous emission by DMABN is an
unusually strong dependence of emission bands on the exciting light wavelength in the
range 290􀀀430 nm. The character of the changes relates to both emission bands and looks
as follows. First, the ratio of the intensity maxima of the components ILE/ICT decreases
in favour of the charge transfer band. At ex = 350 nm the entire spectrum is rather
broad and blurred, and the band maximum is displaced to the red side by about 40 nm.
A subsequent increase in ex to 430 nm causes a further red shift of the entire emission
spectrum to 495 nm. Thus, the resultant shift of the spectrum is anomalously great and
attains 145 nm, with the dependence of the red shift on the excitation wavelength being
almost linear.
The excitation spectra also depend substantially on the registration wavelength reg.
Characteristically, there is an additional structure in these spectra when recording is
made in the range 390 􀀀 420 nm.
Emission decay and anisotropy characteristics of these \red forms" excited at longwave-
length edge of absorption were studied using methods of kinetic picosecond spectroscopy.
The decay times and anisotropy of emission are close to the corresponding parameters of
DMABN upon excitation at the absorption maximum near 300 nm. Results support the
conclusion about luminescence nature of registered emission of DMABN at far antiStokes
excitation.
The given data can be explained taking into account an existence of di erent conformers
of the solute and dipole-dipole interactions between the solute and solvent molecules, with
allowance for the statistics of the microenvironment, which leads to the appearance of a
considerable inhomogeneous broadening of spectra when DMABN is placed into a polar
solution. Hence, DMABN and some other charge transfer molecules in polar solution
may exist as a set of various conformers di ering by their solvate shells. Some of these
conformers possesses absorption and emission spectra well shifted to the longwavelength
and could be selectively excited on the red edge of absorption band.
References
[1] V.I. Tomin, K. Hubisz, and Z. Mudryk, Z. Naturforsch., A: Phys.Sci. 58, 529 (2003)
[2] V.I. Tomin, Opt.Spectr. 101, 2, 206 (2006)
CP 146
168
Reexamination of the LeRoy-Bernstein formula for weakly
bound molecules
Haikel Jelassi, Bruno Viaris de Lesegno and Laurence Pruvost
Laboratoire Aimé Cotton, CNRS II, bat 505, campus d’Orsay
91405 Orsay, France
E-mail: laurence.pruvost@lac.u-psud.fr
The energy law giving the eigen energies of a −cn/Rn − cm/Rm potential (studied by
LeRoy in 1980 [1]), is revisited. For n = 3, m = 6, an analytical law giving the density
of states is deduced. In the context of weakly bound levels an energy law giving the
vibrational number v versus the binding energy ǫ is given. We show that the well-known
LeRoy-Bernstein formula [2] [3] has to be corrected by additional terms, with the first
one varying as ǫ, the second one as ǫ2 and the third as ǫ7/6 [4]. The use of such a law
is discussed in the context of the photoassociation spectroscopy of long range molecular
levels.
References
[1] Theory of deviations from the limiting near-dissociation behavior of diatomic molecules,
R. J. LeRoy, J. Chem. Phys. 73, 6003 (1980).
[2] Dissociation energy and long-range potential of diatomic molecules from vibrational
spacings of higher levels, R. J. LeRoy and R. B. Bernstein, J. Chem. Phys. 52, 3869
(1970).
[3] The Dissociation Energy of the Hydrogen Molecule Using Long-Range Forces, W. C.
Stwalley, Chem. Phys. Lett. 6, 241 (1970).
[4] Reexamination of the LeRoy-Bernstein formula for weakly bound molecules, H. Jelassi,
B. Viaris de Lesegno, L. Pruvost, accepted to Phys. rev. A.
CP 147
169
The singlet X ¡ A and X ¡ B absorption coe±cient of
the K2 system
F. Talbi, M. Bouledroua, and K. Alioua
Laboratoire de Physique des Rayonnements, Badji Mokhtar University,
B.P. 12, Annaba 23000, Algeria
Transitions from the singlet X1§+
g to the ¯rst excited A1§+
u and B1¦u states of the
potassium dimer are studied quantum mechanically. Using the most recent data for the
potential-energy curves for the 4s+4s and 4p+4s molecular systems and the corresponding
dipole transition moments, the reduced absorption coe±cients for temperatures ranging
from 880 to 3000 K have been computed. The simulations of the absorption coe±cient
show that the bound-bound transitions are dominant in the red wing and reveal the
occurrence of a satellite structure around the wavelength 1049 nm. The temperature
e®ect on the satellite position and its amplitude has also been investigated and the results
are compared with recent experimental data.
CP 148
170
Atomic-like shell models for alkali trimers derived
from ab initio calculations
Andreas W. Hauser1, Carlo Callegari1, Wolfgang E. Ernst1 and Pavel Sold´an2
1Institute of Experimental Physics, Graz University of Technology,
Petersgasse 16, A-8010 Graz, Austria
2Charles University in Prague, Faculty of Mathematics and Physics, Department of
Chemical Physics and Optics,
Ke Karlovu 3, CZ-12116 Prague 2, Czech Republic
Alkali metal clusters have received great attention due to their role as bridge between
atomic and solid state physics. Among the smallest clusters, the trimers are of special
interest, since these systems provide complex spectra including Jahn-Teller distortions,
yet the spectra are well defined and still accessible via ab initio calculations.
The experimental spectra, as well as ab initio calculations, show a regular pattern of
electronic states. High level ab initio calculations [CCSD(T), CASPT2] provide detailed
information about the participating electronic orbitals, and allow us to rationalize the
observed patterns in terms of simplified shell models.
For the low-spin states of K3 the standard electron-droplet model offers a qualitative
explanation.1 In this simplified picture the electronic states are interpreted as singleelectron
excitations into delocalized molecular orbitals with typical atomic-like shape.
For the description of the quartet manifolds of K3, K2Rb, KRb2 and Rb3 we utilize the
eigenstates of a harmonic oscillator in a quantum-dot-like confining potential.2
References:
1) A. W. Hauser, C. Callegari, W. E. Ernst and Pavel Sold´an, J. Chem Phys., submitted
2) J. Nagl, G. Aub¨ock, A. W. Hauser, O. Allard, C. Callegari, and W. E. Ernst, Phys.
Rev. Lett. 100, 63001 (2008)
CP 149
171
First observation and analysis
of the (1; 2)1¦ states of KCs
L. Busevica1, R. Ferber1, O. Nikolayeva1, E. A. Pazyuk2,
A. V. Stolyarov2, and M. Tamanis1
1Laser Centre, University of Latvia, 19 Rainis Boulevard, LV-1586 Riga, Latvia
2Department of Chemistry, Moscow State University, Moscow, 119899, Russia
E-mail: Laureta.Busevica@lu.lv
In spite of the fact that the KCs molecule is among prospective objects for production of
ultracold polar molecules, empirical data on its ground state potential have been obtained
only very recently [1]. There are still no experimental spectroscopic data on any of KCs
excited state, and all existing information comes from ab initio calculations [2]. We
present ¯rst observation of laser induced °uorescence (LIF) for the (1; 2)1¦ states of
KCs studied by Fourier transform spectroscopy using a Bruker IFS125HR, with 0.03
cm¡1 resolution. KCs molecules were formed at 280oC in the sealed cylindrical glass
cell containing K (natural isotope mixture) and Cs metals. The LIF D(2)1¦ ! X1§+
spectra have been excited by tuning within 15280 - 15140 cm¡1 a diode laser with 130
mW Mitsubishi ML101J27 laser diode. The B(1)1¦ ! X1§+ LIF spectra have been
obtained with excitation frequencies 14400 - 14500 cm¡1 by a diode laser with 50 mW
Hitachi HL6750 laser diode. Lasers were mounted in home made external cavity resonators
(Littrow con¯guration), with a grating serving as a feedback source. Term values of
the (1; 2)1¦ states in KCs have been obtained by adding transition frequencies to the
respective ground state (vX; JX)X1§+ term values using accurate X1§+ state energy
level data from [1]. The dependencies of the (1; 2)1¦ states term values on the factor
J(J + 1) have been plotted. In particular, for the D(2)1¦ state the rotationless term
values covered the energy range from ca. 15400 to 16400 cm¡1, spanning the J range
from 16 to 205. Preliminary vD identi¯cation was suggested. The dependencies have been
compared with their theoretical counterparts based on calculations in [2]. The analysis
has revealed a noticeable deviation from regular dependence caused, most probably, by
spin-orbit interaction of the D(2)1¦ state with the (3)3§+ state and, especially, with the
very closely lying (2)3¦ state, as predicted in [2]. The work on vibrational assignment
and potential energy curves construction of the states under study is in progress.
Support by Latvian Science Council grant No. 04.1308 is gratefully acknowledged by Riga
team. O.N. acknowledges support from European Social Fund. Moscow team acknowl-
edges support by the Russian Foundation for Basic Researches grant No. 06-03-32330a.
References
[1] R. Ferber, I. Klincare, O. Nikolayeva, M. Tamanis, A. Pashov, H. KnÄockel and E.
Tiemann, J. Chem. Phys., to be published.
[2] M. Korek et al., Can. J. Phys. 78, 977 (2000); M. Korek et al., J. Chem. Phys. 124,
094309 (2006); M. Aymar and O. Dulieu, private communications.
CP 150
172
High resolution spectroscopy and IPA potential
construction of a3§+ state in KCs
R. Ferber1, O. Nikolayeva1, M. Tamanis1, K. KnÄockel2, E. Tiemann2, and A. Pashov3
1Laser Centre, University of Latvia, 19 Rainis Boulevard, LV-1586 Riga, Latvia
2Institute of Quantum Optics, Leibniz University Hannover, Welfengarten 1, 30167
Hannover, Germany
3Department of Physics, So¯a University, 5 J. Bourchier blvd., 1164 So¯a, Bulgaria
Study of a3§+ states of heteronuclear alkali dimers has a strong motivation in supplying
necessary spectroscopic data for producing ultra-cold molecular species in their ground
state. We present the analysis of high resolution laser induced °uorescence (LIF) spectra
to the a3§+ state of KCs, see also [1]. The °uorescence has been studied using a Bruker
IFS125HR Fourier transform spectrometer, with a typical resolution of 0.03 cm¡1. KCs
molecules were produced at 280oC in a sealed cylindrical glass cell containing K and Cs
metals. For excitation a single mode ring dye laser Coherent 699-21 with Rhodamine 6G
dye was used as a light source. Excitation frequencies were selected between 16870 cm¡1
and 17280 cm¡1 and measured by a wavemeter (HighFinesse WS6) with about 0.015 cm¡1
accuracy. The laser frequencies were tuned until the LIF signal to the a3§+ state of KCs,
as monitored by the Fourier spectrometer in the preview mode, exhibited a maximal
value. LIF observed between 13700-14200 cm¡1 revealed clear hyper¯ne structure and
therefore was attributed as °uorescence to the a3§+ state. In the same spectra LIF to
the ground state was present as well. Only P and R transitions were observed in LIF
to both the a3§+ and the X1§+ states. The upper state exited in our experiments is
most likely (4)1§+ perturbed by (3)3§+ and (2)3¦ states. Term values of the a3§+ state
in KCs have been obtained by subtracting the transition frequencies from the respective
excited state (v0; J0) term value. This term value was obtained by adding the energy
of the corresponding level of the X1§+ state, calculated from the analysis in [1], to the
respective (i.e. originating from the same upper state (v0; J0)) transition frequencies.
At current research stage we have assigned 681 LIF lines in 48 LIF progressions to the
a3§+ state spanning v¤ from 1 to 21 and J from 23 to 143. The symbol v¤ means
the preliminary current assignment of vibrational quantum numbers. A ¯rst empirical
potential of the a3§+ state is presented, obtained by the Inverted Perturbation Approach
(IPA) method [2]. The work on vibrational assignment and potential energy curve of the
a3§+ state is still in progress.
Support by Latvian Science Council grant No. 04.1308 is gratefully acknowledged by the
Riga team. O.N. acknowledges support from European Social Fund. The Hannover team
acknowledges support through SFB407 by DFG. A. P. acknowledges partial support from
the Bulgarian National Science Fund Grant No. VUF 202/06.
References
[1] R. Ferber, I. Klincare, O. Nikolayeva, M. Tamanis, A. Pashov, H. KnÄockel and E.
Tiemann, J. Chem. Phys., to be published.
[2] A. Pashov, W. Jastrz»ebski, and P. Kowalczyk, Comput. Phys. Commun. 128, 622
(2000)
CP 151
173
Determination of first-order molecular
hyperpolarizability of ethyl
5-(4-aminophenyl)-3-amino-2,4-dicyanobenzoate
using steady-state spectroscopic measurements and
quantum-chemical calculations
J´ozef Heldt, Marek J´ozefowicz, Janina R. Heldt
University of Gdansk, Institute of Experimental Physics,
ul. Wita Stwosza 57, 80-952 Gdansk, Poland
In recent years, molecules with large optical non-linearities have been extensively studied
due to their potential applications in various optical devices. Some organic molecules
with donor and acceptor groups connected by a π-conjugated bridges show very large
first-order hyperpolarizability (β). The existence of electronically excited states with
strong intermolecular charge transfer (ICT) character is an essential prerequisite for large
non-linear optical properties.
Ethyl 5-(4-aminophenyl)-3-amino-2,4-dicyanobenzoate (EAADCy) and its derivatives, organic
molecules containing separate electron donor and electron acceptor groups, belong
to biphenyl derivatives in which a large dipole moment change between ground (S0) and
the first excited (S1) states as well as a large transition moment were measured. It is well
known that first-order hyperpolarizability (β) depend on several spectroscopic parameters
of the two-level model of organic molecule (J.L. Oudar, D.S. Chmla, J. Chem. Phys. 66
(1977) 2664):
β ∝ ΔμegM2
eg
E2
eg
(1)
where Δμeg – difference in dipole moment between ground and excited state, Meg – transition
dipole moment, Eeg – transition energy. Therefore, in this communication we present
a scrupulous analysis of the first-order hyperpolarizabilities of molecules under study. The
calculated (using semiempirical calculations, CAChe WS 5) βtheo values are discussed in
relationship to the experimental data βexp obtained from steady-state spectroscopic measurements.
Acknowledgements
This work was partially supported by the research grant of the University of Gdansk,
BW-5200-5-0051-8.
CP 152
174
Electronic structure of the [Au2(dmpm)(i – mnt)]
complex
J. Mu˜niz, L.E. Sansores, A. Mart´ınez, R. Salcedo
Instituto de Investigaciones en Materiales, Universidad Nacional Aut´onoma de M´exico.
Apartado Postal 70-360, M´exico DF 04510, M´exico
Compound [Au2(dmpm)(i – mnt)] was synthesized by Tang et al [1] as part of a series of
dinuclear gold compounds that have intra and inter molecular Au–Au interaction. In this
work a theoretical study of this complex is presented. Full geometry optimization at MP2
level was performed on one and two molecules. The basis set used is LANL2DZ for Au and
6-31++G** for all other atoms. The structural parameters obtained for a single molecule
show that the aurophilic interaction is present with a Au–Au distance of 3.0˚A. A scanning
of the potential energy surface at the MP2 level was done by changing the intermolecular
gold gold distance between two units of the compound and a minimum was found at
3.3˚Awith an interaction energy of 5 kcal/mol which is consistent with the binding energy
found in the experiment on this type of complexes. Excited states calculations were also
carried out to study the optical spectra observed. The results are in good agreement
with those found in experiment, the emission and absorption bands are generated by
Metal Ligant Charge Transfer (MLCT) and Metal Centered Charge Transfer (MCCT)
interactions, respectively.
References
[1] S.S Tang, C.-P. Chang, I.J.B. Lin, L.-S. Liou, J.-C. Wang, Inorg. Chem. 36, 2294
(1997)
CP 153
175
A lecture demonstration of quantum erasing
on a photon-by-photon basis
Todorka L. Dimitrova1 and Antoine Weis2
1Paisii Hilendarski University, Plovdiv, Bulgaria
2Physics Department, University of Fribourg, Switzerland
The introduction of the wave-particle duality in quantum mechanics courses often starts
by a discussion of the famous Gedankenexperiment in which a double slit is illuminated
by single photons. The classical interference pattern on the screen can then be explained
in terms of the superposition of a large number of single photon events, in which each
of the photons has passed both slits simultaneously. In recent years we have developed
two lecture demonstration experiments of this e®ect: a ¯rst version using a double slit
with a single photon CCD camera [1,2], and a second version using two-path interference
in a Mach-Zehnder interferometer (MZI) combined with photomultiplier detection [2]. In
the latter apparatus we vary the path di®erence of the interfering beams periodically by
modulating one of the MZI mirrors with a piezo-transducer, and displaying the outgoing
light intensity on an oscilloscope. Using strong light and a photodiode one observes
smooth fringes, while the use of strongly attenuated light, and a photomultiplier reveals
the individual photon structure of the fringes. In that case photon clicks can also be
rendered acoustically. This apparatus can be used to demonstrate many e®ects related
to single photon interference in an undimmed large auditorium.
Recently we have extended the latter experiment for demonstrating the phenomenon of
quantum erasing. Interference fringes are a consequence of the indistinguishability of
the paths taken by the particle in the interferometer. Any attempt to put individual
labels on the particles in each path leads to a disappearance of interference. This can be
demonstrated in a simple way by inserting orthogonally oriented linear polarizers in the
two paths of the MZI. When doing so the interference fringes on the screen are made to
disappear. However, the which-way information imposed by the polarizers can be erased
after the particles have left the interferometer. In practice this is realized by the insertion
of a third polarizer, the eraser, oriented at §45± before the screen. The erasing polarizer
destroys the polarization labels and makes the interference reappear, a phenomenon called
quantum erasing. In terms of classical wave superposition the phenomenon is readily
understood, but its understanding at the single photon level presents some di±culties for
students. From a didactical point of view it is a nice example for introducing the concept
of entanglement: while being in the interferometer the external degree of freedom (path)
of each photon is entangled with its internal state (polarization).
The versatile apparatus described above can be used to demonstrate quantum erasing on
a photon-by-photon basis in an impressive manner.
References
[1] A. Weis and R. Wynands, Three demonstration experiments on the wave and particle
nature of light, PhyDid, 1/2 (2003) 67-73.
[2] T. L. Dimitrova and A. Weis, The wave-particle duality of light: a demonstration
experiment, Am. J. Phys. 76 (2008) 137-142.
CP 154
176
Stark shift in the Cs clock transition frequency:
A new experimental approach
J.-L. Robyr, P. Knowles, A. Weis
University of Fribourg, Department of Physics, Fribourg, Switzerland
The precision of microwave atomic clocks is approaching the 10−16 level, and at this
precision, more refined accounting of the perturbations affecting the cesium hyperfine
level splitting must be carefully considered. The AC Stark shift induced by blackbody
radiation via the polarizability of the Cs atom is one such disturbance. The past few
years have seen a renewed interest in the measurement and theoretical description of that
effect. We report on progress towards the application of coherent population trapping
(CPT) in a pump-probe experiment on a thermal atomic beam for a new measurement
of the third order scalar and tensor polarizabilities that underlie the blackbody shift.
The polarizability, , describes the energy shift of a level via E(n, LJ , F,MF ) = −1
2 E2,
and is traditionally expanded in a perturbation series whose first few terms are
= (2)
0 (n,LJ ) + (3)
0 (n, LJ , F) + (3)
2 (n, LJ , F)
3M2
F − F(F + 1)
I(2I + 1)
.
Only the third-order perturbation terms (3)
0 (scalar) and (3)
2 (tensor) create a shift affecting
the Cs hyperfine structure, and hence the clock transition frequency 00(3, 0!4, 0).
Recent examination of the theory underlying the polarizability[1] has corrected a long–
hidden sign error, and several recent measurements of the AC and DC Stark shifts of
00 are not consistent with each other. We wish to help clarify the situation by a new
experiment.
The principle of the experimental method is to create a hyperfine coherence using CPT in
an atomic beam, to allow the coherence to evolve for a certain time in controlled magnetic
and electric fields, and finally to probe the phase accumulated in the field region. Part
of the phase difference will be proportional to the differential level shifts produced by
the applied electric field and thus give access to both the third-order scalar and tensor
polarizabilities of the Cs ground state. We plan to measure the shifts in all accessible
MF levels, and not only in the MF=0 clock transition states. A degenerate CPT version
of the method was successfully used by us to measure[2] the tensor Stark shift (3)
2 , a
value roughly two orders of magnitude smaller than the scalar (3)
0 which dominates the
contribution to the black body shift.
Details of the apparatus and the physics under study will be presented.
[1] S. Ulzega, A. Hofer, P. Moroshkin, and A. Weis, Europhys. Lett. 76, 1074 (2006)
[2] C. Ospelkaus, U. Rasbach, and A. Weis, Phys. Rev. A 67, 011402 (2003).
CP 155
177
Magnetic Field Imaging With Arrays of Cs
Magnetometers: Technology and Applications
P. Knowlese, G. Bisone,h, N. Castagnae, A. Hofere,
A. Mtchedlishvilil , A. Pazgaleve,l,
1, A. Weise,
and including the PSI nEDM collaborationa
−
l
aPhysikalisch Technische Bundesanstalt, Berlin, Germany
bLaboratoire de Physique Corpusculaire, Caen, France
cJagellonian University, Cracow, Poland
dJoint Institute for Nuclear Research, Dubna, Russia
eUniversity of Fribourg, Switzerland
f Institut Laue Langevin, Grenoble, France
gLaboratoire de Physique Subatomique et de Cosmologie, Grenoble, France
hBiomagnetisches Zentrum Jena, Germany
iKatholieke Universiteit, Leuven, Belgium
jJohannes-Gutenberg-Universit¨at, Mainz, Germany
kTechnische Universit¨at M¨unchen, Germany
lPaul Scherrer Institut, Villigen PSI, Switzerland
1Ioffe Physical Technical Institute, St. Petersburg, 194021, Russia
The precision measurement of magnetic fields is of interest for both applied and funda-
mental physics. In many of these cases, atomic cesium magnetometers pumped by a laser
(LsOPM) or by a discharge lamp (LaOPM) and operating via simultaneous application
of optical and magnetic resonance, have the necessary sensitivity[1]. The shift from using
multiple lamps to using a single laser (with holographic beam splitting) as a light source for
driving many sensors has improved the suitability of the LsOPM for use in multi-channel
applications. A successful effort in the mass production of paraffin anti-relaxation coated
Cs vacuum cells, along with a compact sensor design which maintains a high magnetic
sensitivity ( 20 fT/
p
Hz), shows that the multi-sensor ( 50) approach to field imaging
is realistic with LsOPMs. The compact sensors (30 × 40 × 40 mm3) are vacuum com-
patible and, once assembled, relatively rugged and insensitive to vibration and shock.
Successful all-digital control of the magnetometer, as performed by dedicated FPGA sys-
tems including real-time feedback between different sensors in the array, indicates that
the initial hurdles slowing the creation of a fully operational compact multi-sensor optical
magnetometry array have been overcome.
Developments related to the sensors and their in-array operation will be detailed. Future
applications, such as the control of the magnetic field stability for the new neutron electron
dipole moment experiment at PSI as well as in the domain of cardiomagnetic field imaging,
will be explained.
[1] S. Groeger, A. S. Pazgalev, and A. Weis, Appl. Phys. B 80, 645 (2005).
CP 156
178
Performance of a compact dark state Magnetometer
R. Lammegger1 and L. Windholz1
1Institute of Experimental Physics TU-Graz, Petersgasse16, 8010 Graz
Measuring magnetic ¯elds by means of spectroscopic-optical methods has advantages in
many respects. E.g. in best case the magnetic ¯eld sensor of an optical magnetometer can
only be made of a (nonmagnetic) glass cell containing a tiny amount of an alkali metal
non perturbing the external magnetic ¯eld. Moreover the optical sensor is working near
room temperature. Thus unlike to the (in common more sensitive) superconducting quan-
tum interference device (SQUID) magnetometer an extensive cooling down to cryogenic
temperatures can be avoided.
We consider a compact vertical surface emitting laser (VCSEL) based dark state Mag-
netometer. In such kind of optical magnetometer the zeeman split (magnetic sensitive)
components of the coherent population trapping (CPT) resonance spectrum are used to
determine an external magnetic ¯eld. By applying the Breit-Rabi formula the value of
the external magnetic ¯eld can be derived directly from the frequency of the magnetic
sensitive CPT resonance components.
In our investigations the advantages and constraints of such a compact magnetometer
type in terms of sensitivity, measurement bandwidth, noise and in°uence of magnetic
¯eld gradients are outlined. E.g. in our actual magnetometer setup a sensitivity down to
10 pT=
p
Hz is reached.
The work is founded by the Fonds zur FÄorderung der wissenschaftlichen Arbeit (FWF)
(Project No.: L300-N02)
CP 157
179
Laser-induced transport e®ect and laser induced-line
narrowing mechanism for laser excitation in 87Rb
atomic vapors in a ¯nite-size bu®er-less cell.
A.Litvinov1, G. Kazakov2, B. Matisov2
1A.F. Io®e Physico-Technical Institute RAS, St.Petersburg, Russia
2St. Petersburg State Polytechnic University, St.Petersburg, Russia
Coherent population trapping (CPT) and double radio-optical resonance (DROR) are
quantum nonlinear e®ects. Both these e®ects are the base for the creation of high preci-
sion magnetometers and atomic frequency standards.
We study the in°uence of the laser induced transport (LIT) [1] and the laser induced line
narrowing (LILN) [2] e®ects on the DROR and CPT resonance line shape for excitation in
87Rb atomic vapors in wall-coated and uncoated cell. We take into account both hyper¯ne
and Zeeman structures of the ground and the excited states of 87Rb atoms as well as the
probabilities of spontaneous transitions. We investigate the dependence of the resonance
shape on the length of the cell, on the type of boundary conditions, on the polarization
and intensity of laser and microwave ¯elds, and on the laser line width ("narrow-band"
and "broad-band").
Laser induced transport in DROR: The ¯rst the LIT was predicted for three-level
model in [1]. We show that the LIT takes place in bu®er-less cell with real 87Rb atoms.
The physical essence of the LIT e®ect is the caused by the Doppler e®ect velocity-
selectivity of the interaction of "narrow-band" laser ¯eld with atoms, resulting in Bennett
dips and peaks in the velocity distribution of atoms in the ground state sublevels. Asym-
metry of the two velocity distributions gives rise to the opposite-directed (along the laser
propagation direction) °uxes of the atoms in the ground state sublevels. Therefore, a °ux
of the population inversion (or, equivalently, of the longitudinal magnetization) arises.
This behavior one experimentally can obverse as the transmission peak in the centre of
the DROR signal [3]. LIT e®ect is most pronounced for "narrow-band" laser pumping.
Laser induced line narrowing in CPT resonance: The LILN of the CPT resonance
realizes only in the case of excitation by "narrow-band" laser. We established that for
the LILN mechanism the parameters (the amplitude and width) of the CPT resonance
excited on hyper¯ne transition weakly depend on the cell size and the type of the coating
[4]. When the components of the laser ¯eld are comparable the CPT resonance width
depends linearly on the laser ¯eld intensity. This case was investigated in [5] where
the formation of CPT resonance on Zeeman sublevels was studied. In contrast for the
electromagnetically-induced transparency (EIT) e®ect (where one laser ¯eld is drive and
the other - probe) the EIT width increases proportionally to the square root of the drive
¯eld intensity [6].
This work is supported by INTAS-CNES-NSAU grant, project 06-1000024-9321.
References
[1] B. D. Agap'ev, M. B. Gornyi, and B. G. Matisov, Sov.Phys. JETP 65, 1121 (1987).
[2] M. S. Feld and A. Javan, Phys.Rev. 2, 177 (1969).
[3] A. S. Zibrov, A. A. Zhukov, V. P. Yakovlev et al., JETP Letters 83, 168 (2006).
[4] G. Kazakov, B. Matisov, A. Litvinov, and I. Mazets, J. Phys. B 40, 3851 (2007).
[5] A. Huss, R. Lammegger, and L. Windholz et al., JOSA B 23, 1729 (2006).
[6] A. Javan, O. Kocharovskaya, H. Lee et al., Phys. Rev. A 66, 013805 (2002).
CP 158
180
Population transfer, light storage, and superluminal
propagation by bright-state adiabatic passage
G.G. Grigoryan1, G. Nikoghosyan1, A. Gogyan1,2, Y.T. Pashayan-Leroy2, C. Leroy2, and
S. Gu´erin2
1Institute for Physical Research, 0203, Ashtarak-2, Armenia
2Institut Carnot de Bourgogne, UMR 5209 CNRS - Universit´e de Bourgogne, BP 47870,
21078 Dijon, France
The practical implementation of quantum information requires to develop techniques of
mapping of light pulses into the excitation of media in order to allow the subsequent
retrieval of the stored information. Recently, broad attention has been focused on the
possibility of ”light-storage” under the conditions of electromagnetically induced transparency
(EIT), as proposed by Fleischauer and Lukin [1]. The method is based on the
existence of a dark state in Raman interaction of a -type system. We present an alternative
method for the storage and retrieval of optical information using adiabatic passage
along a bright state (b-state). We present theoretical calculations demonstrating that a
light storage can take place in media where EIT does not occur. This method is achieved
for short pulses of interaction time shorter than the relaxation times. Such a bright state
allows population transfer by a Stimulated Raman adiabatic passage using an intuitive
pulse sequence (process named b-STIRAP), as demonstrated in Pr+3Y2SiO5 [2].
In the present work we obtain an analytical solution of the set of Maxwell-Shr¨odinger
equations describing the propagation of two laser pulses in a -type medium for an intuitive
pulse sequence. We show that it allows an effective storage and retrieval of an
optical pulse. The probe pulse that is switched on later than the control pulse propagates
in the medium with the velocity greater than the light velocity (superluminal propagation).
When the control pulse is switched off, the shape of the probe pulse is mapped into
the coherence of the lower states. After a subsequent switching on of the control pulse
the probe pulse is shown to be completely restored.
We have analyzed population transfer process in a medium via b-state during the pulse
propagation. We show that for specific interaction parameters one can achieve an efficient
population transfer. We have estimated the maximal length up to which population
transfer is still possible.
References
[1] M. Fleischauer and M.D. Lukin, Phys. Rev. Lett. 84 , 5094 (2000)
[2] J. Klein, F. Beil, and T. Halfmann, Phys. Rev. Lett. 99, 113003 (2007)
CP 159
181
Population switching of Na and Na2 excited states by
means of interference due to Autler-Townes e®ect
C. Andreeva1;2, N. Bezuglov3, A. Ekers1, K. Miculis1, B. Mahrov1, I. Ryabtsev4,
E. Saks1, R. Garcia-Fernandez5, K. Bergmann5
1Laser Centre, University of Latvia, LV-1002 Riga, Latvia
2Institute of Electronics, Bulgarian Academy of Sciences, So¯a 1784, Bulgaria
3Faculty of Physics, St.Petersburg State University, 198904 St. Petersburg, Russia
4Institute of Semiconductor Physics, 630090 Novosibirsk, Russia
5University of Kaiserslautern, Dept. of Physics, D-67653 Kaiserslautern, Germany
We present our results on the exploitation of interference e®ects for population switching
of excited states. Our calculations show that spatial distribution of the atomic excitation
can be controlled by employing the Autler-Townes e®ect [1] in a laser coupling scheme
enabling Ramsey interference [2]. Interference fringes in the Autler-Townes spectra have
been reported in [3] for the case of a closed three-level system coupled by a resonant pulsed
pump laser in the ¯rst excitation step, creating time-varying dressed states, which were
probed by a simultaneous probe pulse in the second excitation step. In our experiment,
a supersonic sodium beam is crossed by two cw laser beams, which couple an open three-
level ladder system. The lasers are focused in such a way that a strong and short (tightly
focused) pump laser couples the two lower levels jgi and jei , and weak and long (less
tightly focused) probe laser couples the intermediate jei and the upper level jfi. The
pump laser thus creates two spatially varying dressed states, whose energy di®erence is
determined by the pump ¯eld Rabi frequency and its detuning from resonance.
Our numerical calculations of density matrix equations of motion using the split propaga-
tion technique [4] show that with this arrangement the spatial distribution of populations
of excited atomic or molecular states can be precisely controlled by varying the laser
frequencies and intensities. When the frequencies of both laser are ¯xed, the excitation
of the upper level can take place at two spatial locations. This leads to two alternative
excitation pathways of the level jfi , where the probability amplitude of this level after
the second crossing point is determined by the constructive or destructive interference
of both excitation pathways. Our simulations show [5] that interference fringes in the
excitation spectrum of the upper level can be resolved when counter-propagating laser
beams are used to avoid residual Doppler broadening. We show that moderate detunings
of the strong dressing laser are favorable for the observation of interference e®ects. The
experimental realization of the idea is in progress.
The work is supported by the EU TOK Project LAMOL, European Social Fund, Latvian
Science Council, and RFBR Grant 05-02-16216.
References
[1] S.H. Autler, C.H. Townes, Phys.Rev. 100, 703 (1955).
[2] N.F. Ramsey, Molecular Beams (Clarendon, Oxford, 1989).
[3] S.R. Wilkinson, A.V. Smith, M.O. Scully, E. Fry, Phys. Rev. A53 (1), 126 (1996).
[4] M.D. Fiet, J.A. Fleck, A. Steiger, J. Comput. Phys. 47, 412 (1982).
[5] N.N. Bezuglov, R. Garcia-Fernandez, A. Ekers, K. Miculis, L.P. Yatsenko, K. Bergmann,
"Consequences of optical pumping and interference for excitation and spectra in a coher-
ently driven molecular ladder system" (in preparation).
CP 160
182
High-rank polarization moments influence on the
CPT resonance obtained on two-level degenerated
system
E. Alipieva, E. Taskova, S. Gateva and G. Todorov
Academician Emil Djakov Institute of Electronics, Bulg. Acad. Sc.,
72 Tzarigradsko Chaussee, 1784 Sofia, Bulgaria
E-mail: alipieva@ie.bas.bg
In two-level degenerated system Coherent Population Trapping (CPT) resonance is due
to the interference between the Zeeman sub-levels with m=2, created by interaction
of resonance linear polarized laser beam with the atoms. The resonance is detected by
sweeping magnetic field B0 around its zero value - Hanle configuration. The multiphoton
processes and the low relaxation rate of the lower levels allow creation of coherences
between sub-levels with m>2. The laser field transfers this coherence in the fluorescence
from the upper level and thus changes the shape of CPT resonance.
The investigations were performed on the D1
87Rb line (F=2!F=1 transition) in an
uncoated cell. The comparative - theoretical and experimental investigation, performed
of the shapes of the CPT resonances registered in fluorescence shows that the high-rank
polarization moments (HRPMs, m>2) influence them at low excitation power and at
high excitation powers as well. The HRPMs conversion is proved to cause the CPT
resonance shape peculiarities at the center of the resonance: at low excitation power,
a specific difference from the Lorentzian shape is observed, while at a high power of
excitation, an inverted structure is registered [1].
All resonances in Hanle configuration are centered at zero magnetic field. The integration
of the modulation and coherent spectroscopy allows resonances due to different
polarization moments to be resolved and enlarge the application area of the investigations
[2,3]. A.c. electromagnetic field (EMF) applied collinearly to the B0 modulates
the frequency difference between the Zeeman sub-levels. The Larmor frequency becomes:
!=!0+!1cos
t, where
is the EMF frequency. The intensity of the scattered from the
atoms light is modulated and shows resonance increasing when EMF frequency is multiple
to the Zeeman sub-levels difference. When EMF is applied the side-band resonance which
corresponds to coherence created between m=+2 and m=−2 Zeeman sub-levels appears
first. The parameters of this resonance in dependence of experimental conditions were
investigated.
The results of this investigation are interesting for high-resolution spectroscopy, magnetometry,
and metrology applications.
References
[1] S. Gateva, L. Petrov, E. Alipieva, G. Todorov, V. Domelunksen, V. Polischuk, Phys.
Rev. A76(2), 025401 (2007).
[2] E. Alexandrov, O. Konstantinov, V. Perel, V. Khodovoy, JETP 45, 503-510 (1963);
[3] S. Pustelny, D.F. Jackson Kimball, S.M. Rochester, V.V. Yashchuk, W. Gawlik, D.
Budker, Phys. Rev. A73, 023817 (2006).
CP 161
183
Sub-Doppler fluorescence spectroscopy of Cs-vapour
layers with nano-metric thickness
K. Vaseva1, P. Todorov1, S. Cartaleva1, D. Slavov1, S. Saltiel2
1Institute of Electronics, Bulgarian Academy of Sciences, 72 Tzarigradsko Shosse bld,
1784 Sofia, Bulgaria
2Sofia University, Faculty of Physics, 5 J. Bourchier boulevard, 1164 Sofia, Bulgaria
E-mail: petkoatodorov@yahoo.com
The extensive study of alkali-vapor layers with nano-metric thickness L has been made
possible through the development of cells of L ≤ 1 μm , where the thickness of the vaporlayer
can be varied in an interval around the wavelength λ of the irradiating light [1]. It
was shown that the width of the fluorescence profiles increases with the cell thickness [2].
We present experimental and theoretical studies of the fluorescence spectra on the D2
line of Cs-atomic-layers with L = mλ (m = 0.5, 0.75, 1, 1.25), when irradiated by narrowband
laser light tuned around λ = 852nm. We use the theoretical model [3] based on
the Optical Bloch Equations and obtain qualitative agreement between the theory and
the experiment. The atomic systems are separated in two groups: closed and open. Well
pronounced narrow dip in the fluorescence (superimposed on the top of the sub-Dopplerwidth
fluorescence profile) is observed experimentally only for the open transitions suffering
hyperfine/Zeeman optical pumping, and for L ≥ λ. In the case of closed transition,
non-suffering population loss extremely small peculiarity in the fluorescence profile is observed
for L = 1.25λ [4]. Systematic comparison is made between the fluorescence profiles
amplitude and width, estimated theoretically and experimentally. With laser power the
amplitude and the width of the fluorescence profiles increase, for all cell thicknesses and
all transitions. In agreement with the previous results [2], the width of the transition
profiles is growing with L. However, we report here about the following new peculiarity:
the enhancement rate of the transition width is not constant, namely it is larger for L
varying in the interval 0.75λ ≤ L ≤ λ than that varying in the interval λ ≤ L ≤ 1.25λ.
We show that the width of the fluorescence profiles strongly depends on the layer thickness
(with variations as small as 213nm). These results can be used for spectral investigations
of atoms confined in nano volumes, as well as for spectroscopy of miniature gas discharges.
Authors are grateful to Prof. D. Sarkisyan for providing the nano-cell, as well as to
INTAS (grant: 06-1000017-9001), Indo-Bulgarian program of cooperation in science and
technology (grant No. BIn-2/07) and the French-Bulgarian Rila collaboration (French
grant: 98013UK, Bulgarian grant: 3/10), for the partial support.
[1] D. Sarkisyan, D. Bloch, A. Papoyan, M. Ducloy, Opt. Commun. 200, 201 (2001).
[2] D. Sarkisyan, T. Varzhapetyan, A. Sarkisyan, Yu. Malakyan, A. Papoyan, A. Lezama,
D. Bloch, M. Ducloy, Phys. Rev. A69, 065802 (2004).
[3] C. Andreeva, S. Cartaleva, L. Petrov, S. M. Saltiel, D. Sarkisyan, T. Varzhapetyan,
D. Bloch, M. Ducloy, Phys. Rev. A76, 013837 (2007).
[4] K. Vaseva, P. Todorov, D. Slavov, S. Cartaleva, K. Koynov, S. Saltiel, ACTA PHYSICA
POLONICA A, Vol. 112, No. 5, 865 (2007).
CP 162
184
Absorption in the saturation regime of Cs-vapour
layer with thickness close to the light wavelength
P. Todorov1, S. Cartaleva1, K. Vaseva1, C. Andreeva1, I. Maurin2, D. Slavov1,
S. Saltiel3
1Institute of Electronics, BAS, 72 Tzarigradsko Shosse boulevard, 1784 Sofia, Bulgaria
2Laboratoire de Physique des Lasers UMR 7538 du CNRS, Universit`e Paris-13, France
3Sofia University, Faculty of Physics, 5 J. Bourchier boulevard, 1164 Sofia, Bulgaria
E-mail: petkoatodorov@yahoo.com
Absorption spectrum of an atomic vapour layer, which thickness L is close to the wavelength
of the irradiating light λ, shows a narrow structure on the Doppler broaden background.
This is attributed to Dicke narrowing [1,2], which is due to the coherent contribution
of all velocity group atoms into the narrow absorption signal at the position of the
central frequency of the transition. This is possible because the Doppler shift is eliminated
by the transient regime of atom-light interaction when the transient interaction time is
shorter than the lifetime of the exited state. The maximum contribution of Dicke effect
is achieved for L = λ/2, while the effect is cancelled at L = λ[2]. It has been shown that
a revival (with an amplitude lower than that at L = λ/2) of the Dicke narrowing occurs
for L = (2n+1)λ/2. The maximum amplitude of the Dicke revival is for L = (3/2)λ[2-5].
We present the absorption spectra in saturation regime on the D2 line of Cs-vapour-layer
with L = (5/4)λ, irradiated by tunable (around λ = 852nm diode laser light[6]. The
atomic gas is confined in a nano-cell [7]. Different saturation behavior for closed and open
optical transitions reported before in [6,8,9]is studied for cell thickness L = (5/4)λ. For
the closed transition, well pronounced Dicke narrowing is observed starting from low light
intensity and it is preserved even on the saturation deep occurring at high intensity. On
the contrary, the open transitions do not show Dicke resonance under the same conditions.
The observations differ from those for L = (3/2)λ [5], where the Dicke revival is observed
for both closed and open transitions. The result is of basic importance for revealing of
the influence of the optical pumping/saturation processes to the Dicke effect.
We thank D. Sarkisyan for nano-cell, D. Bloch and M. Ducloy for discussions, INTAS (gr.
06-1000017-9001) and Rila collaboration (French gr.: 98013UK, Bulgarian gr.: 3/10).
[1] R. H. Romer, R. H. Dicke, Phys. Rev. 99, 532(1955).
[2] G. Dutier, A. Yarovitski, S. Saltiel, A. Papoyan, et. al., Europhys. Lett. 63, 35 (2003).
[3] D. Sarkisyan, T. Varzhapetyan, A. Sarkisyan, et. al., Phys. Rev. A69, 065802(2004).
[4] I. Hamdi, P. Todorov, A. Yarovitski, G. Dutier, et. al., Laser Physics 15, 987 (2005).
[5] S. Cartaleva, K. Koynov, et. al., Proc. 34th EPS Conf., ECA vol.31F, P-4.008 (2007).
[6]C. Andreeva, S. Cartaleva, L. Petrov, et. al., Phys. Rev. A76, 013837 (2007).
[7] D. Sarkisyan, D. Bloch, A. Papoyan, M. Ducloy, Opt. Commun. 200, 201 (2001).
[8] S. Briaudeau, D. Bloch and M. Ducloy, Europhys. Lett. 35, 337 (1996)
[9] S.Briaudeau, S.Saltiel, D. Bloch, M. Ducloy, Phys. Rev, A57, R3169 (1998)
CP 163
185
Dark and bright resonances in large J systems:
example of K2 molecule
M. Auzins, R. Ferber, I. Fescenko, L. Kalvans, and M. Tamanis
Laser Centre, University of Latvia, 19 Rainis Boulevard, LV-1586 Riga, Latvia
We report the results of an experimental as well as theoretical study of the dark and bright
resonances in the ground state of systems with extremely large angular momentum. It is
shown that, besides the well-known zero-magnetic field suppression of the absorption on
Jg = J → Je = J– 1, J transitions caused by population trapping in the ground Jg state,
optical pumping may induce enhanced absorption as well. This occurs if some conditions
are met on Jg = J→ Je = J + 1 transitions for small magnetic field B values. The latter effect
becomes more pronounced if the J-value increases and disappears if a substantial fraction
of the excited molecules can spontaneously decay to a level that is different from the one
on which the absorption transition started. Bright resonance enhancement is substantially
stronger for excitation with circularly polarized light than for excitation with linearly
polarized light. The experiments were carried out with the K2 molecule, and the results of
our measurements agree reasonably well with numerical simulations that were based on
the optical Bloch equations for the density matrix [1].
K2 molecules were formed in a glass cell that contained K metal at a temperature of
170 °C, and which was placed between the poles of an electromagnet that produced a
magnetic field B up to 10 kG. The Q-type B(1)1Πu ← X1Σ+
g transition to the rovibronic
level with ve = 0 and Je = 104 was excited by a diode laser with a Mitsubishi ML101J27
laser diode at the 15192.29 cm-1 transition frequency. The laser power in the cell was about
20 mW and the laser beam width about 2.5 mm. Dark resonances were observed in the
intensities of linearly polarised laser induced fluorescence with polarization vectors Eobs
both parallel (Ipar) and orthogonal (Iort) to the exciting laser radiation polarization vector
Eexc, which was orthogonal to B. We detected well pronounced dark resonance signals,
with larger contrast in Ipar by about 30% , and signal width about 6 kG, which agreed with
theoretical predictions. Bright resonances had been neither detected nor predicted
previously for such a system because of the presence of “leak” transitions to the Ji-levels
other than the pumped Jg transition.
The authors are grateful for the support from the Latvian State Research programme in
Material Science 1-23/50 and from the ERAF grant
VPD1/ERAF/CFLA/05/APK/2.5.1/000035/018.
References
[1] K. Blush and M. Auzins, Phys. Rev. A 69, 063806 (2004).
CP 164
186
F-resolved bright and dark magneto-optical
resonances at the cesium D1 line
M. Auzinsh, R. Ferber, F. Gahbauer, A. Jarmola, and L. Kalvans
The University of Latvia, Laser Centre, 19 Rainis Boulevard, LV-1586 Riga, Latvia
jarmola@latnet.lv
We present detailed experimental and theoretical studies of F-resolved bright and dark
magneto-optical resonances at D1 excitation of atomic cesium in a vapor cell [1]. Although
these effects have been known for some time [2,3], experimental measurements [4,5] did
not agree with theoretical predictions [6,7]. Previously studied systems have been difficult
to model because several hyperfine levels contributed to the signal simultaneously. The
advantage of the cesium D1 line system considered here is that the hyperfine splitting of
the excited 6P1/2 state exceeds the Doppler width and therefore the hyperfine transitions
from ground state levels Fg = 3, 4 to excited state levels Fe = 3, 4 can be studied
individually despite Doppler broadening.
Cesium atoms in a vapor cell were excited by linearly polarized laser radiation from
an external cavity diode laser and the laser induced fluorescence was detected with a
photodiode in a direction perpendicular to the laser propagation and polarization. The
magnetic field in the observation direction was scanned by means of a Helmholtz coil.
The laboratory magnetic field in the other directions was compensated by two other
Helmholtz coils. Experimentally obtained signals for various laser power densities and
transit relaxation times were compared to the results of a theoretical calculation based on
the optical Bloch equations, which averages over the Doppler contour of the absorption
line and accounts for the contribution of all hyperfine levels, as well as mixing of magnetic
sublevels in an external magnetic field.
In contrast to previous studies which could not resolve the hyperfine transitions, in this
study there is excellent agreement between experiment and theory regarding the sign
(bright or dark), contrast, and width of resonance. The results thus support the theoretical
description of these resonances originally proposed in [6,7]. Renewed confidence in the
theoretical underpinnings of these resonances and a detailed theoretical model could aid
in the design of optical devices based on this effect.
We acknowledge support from the Latvian National Research Programme in Material Sciences
Grant No. 1-23/50, the University of Latvia grant Y2-ZP04-100, the ERAF grant
VPD1/ERAF/CFLA/05/APK/2.5.1./000035/018, and the INTAS projects 06-1000017-
9001 and 06-1000024-9075. F. G., A. J., and L. K. acknowledge support from the ESF.
References
[1] M. Auzinsh, R. Ferber, F. Gahbauer, A. Jarmola, and L. Kalvans, arXiv.org, arXiv:0803.0201.
[2] R. W. Schmieder et al.,Phys. Rev. A 2, 1216 (1970).
[3] G. Alzetta, A. Gozzini, L. Moi, and G. Orriols, Il Nuovo Cimento B 36, 5 (1976).
[4] G. Alzetta et al., Journal of Optics B 3, 181(2001).
[5] A. V. Papoyan et al., J. Phys. B 36, 1161 (2003).
[6] F. Renzoni et al., Phys. Rev. A 63 065401 (2001).
[7] J. Alnis and M. Auzinsh, J. Phys. B 34, 3889 (2001).
CP 165
187
E®ects of hyper¯ne structure on the Autler-Townes
splitting
T. Kirova1, A. Ekers1, N. N. Bezuglov1;2, I. I. Ryabtsev3 , K. Blushs1, and M. Auzinsh1
1 Laser Centre, University of Latvia, LV-1002 Riga, LATVIA
2 Faculty of Physics, St.Petersburg State University, 198904 St. Petersburg, RUSSIA
3 Institute of Semiconductor Physics SB RAS, 630090, Novosibirsk, RUSSIA
The Autler-Townes (AT) e®ect is associated with its typical doublet structure in the
excitation spectrum [1], which is due to the dressing of two energy levels by strong coherent
radiation ¯eld [2]; the dressed states can be observed by an auxiliary weak probe ¯eld
coupled to some third level. It has been extensively studied in detail in atoms [3] and less
extensively also in [4] molecules.
In our recent work [5] we have extended the studies of AT e®ect to atomic and molecular
systems where hyper¯ne structure is present. In the case of a three-state ladder with
hyper¯ne structure in Na coupled by two laser ¯elds, simulations based on a theoreti-
cal model of solving the optical Bloch equations (OBE's) [6] show that application of a
su±ciently strong coupling between the intermediate and the ¯nal states results in full
resolution of the mF Zeeman sublevels of the hyper¯ne levels F. This resolution, however,
vanishes if the hyper¯ne levels can not be initially resolved spectroscopically, which is the
case for most molecular systems.
Currently, work is in progress to understand the above e®ects in the case of both resolved
and unresolved hyper¯ne structure and to predict possible experimental applications. Be-
sides OBE's we employ an alternative method treating the laser-atom system by solving
the Shrdinger's equation to obtain the time evolution of the probability amplitudes. Com-
parison with the simulations based on solving the OBE's shows the same energy positions
of the mF Zeeman sublevels under the action of a strong laser ¯eld but di®erent widths
and intensities of the AT peaks, since no cascading due to spontaneous emission is in-
cluded. Simulations based on Shrdinger's equation show that the increase of the coupling
¯eld strength, compared to the separation between the hyper¯ne components, leads to
rapid decrease (and eventually vanishing) of the intensity of all AT peaks besides the two
side ones. The latter is explained in view of the creation of multiple dark states in a
multilevel system coupled by a strong ¯led.
Support by the EU FP6 TOK project LAMOL, ERDF project S35-ESS38-100, European
Social Fund, Latvian Science Council, and RFBR grant No. 08-02-00220 is acknowledged.
References
[1] S. H. Autler and C. H. Townes, Phys. Rev. 100, 703 (1955)
[2] C. Cohen-Tannoudji et al., Atomo-Photon Interactions, (Wiley, New York, 1992)
[3] J. L. Picque and J. Pinard, J. Physics B 9, L77 (1976); P. T. H. Fisk et al., Phys.
Rev. A 33, 2418 (1986); F. C. Spano, J. Chem. Phys. 114, 276 (2001)
[4] J. Qi et al., Phys. Rev. Lett. 83, 288 (1999); R. Garcia-Fernandez et al., Phys. Rev.
A 71, 023401 (2005)
[5] T. Kirova, et al., in: Proceedings of the XIV National Conference "Laser Physics-
2007", (Ashtarak, Armenia, 2008) in print
[6] M. Auzinsh et al., Opt. Commun. 264, 333 (2006)
CP 166
188
Ladder and Lambda systems electromagnetically induced transparency in
thin and extremely-thin cells
A. Sargsyan1, M.G.Bason2, D. Sarkisyan1, Y. Pashayan-Leroy1,3, A.K.Mohapatra2,
C. S. Adams2
1Institute for Physical Research, NAS of Armenia, Ashtarak-0203, Armenia
2Department of Physics, Durham University, Durham DH1 3LE, United Kingdom
3Laboratoire de Physique de l’Université de Bourgogne, Dijon, France
The recent interest in the effect of electromagnetically induced transparency (EIT)
phenomenon is caused by a number of important applications. We study the possibility
for miniaturization of alkali cells for application in the EIT experiments without
compromising the EIT resonance parameters [1].
We present results on an EIT ladder system of the 85Rb, 87Rb, 5S-5P-nD(mS)
transitions with n = 5 as well as involving highly excited Rydberg states with n = 26
and m = 48. For this purpose a recently developed multi-region (MR) high temperature
cell containing Rb vapor has been used. The construction of MR cell allows us to study
EIT effect in atomic vapor of thickness L= 4 mm, 2 mm, and 0.5 - 6 μm. The design of
MR cells with length L in the range of 30 nm - 10 mm will be presented. It is
demonstrated that in 4 mm and 2 mm-long cells it is possible to realize a robust
formation of EIT resonance in counter-propagating geometry [2] with a high contrast
(50 - 60%) and with a sub-natural linewidth. The fine structure of 26 D5/3, 3/2 has been
measured. For 5S-5P-48S system a pronounced Stark broadening of the EIT resonance
is observed. The short thickness of the cell allows one to provide a tight focusing to
achieve high intensity. Under this condition efficient 2-photon absorption has been
detected, even when the thickness L is reduced to 6 μm.
We present experimental and theoretical results on an EIT ladder system of the
85Rb, 87Rb, 5S-5P-5D for a pure Rb vapour column with L of the order of light
wavelength (λ =780 nm) and varying in the range of (0.75 to 6) λ. It is shown that in the
case when coupling laser frequency is resonant with atomic transition the linewidth of
the EIT resonance (6 to 8 MHz) is weakly dependent on the thickness as ~ L-0.25. The
explanation is that the contribution of atoms with small velocity projection in the laser
radiation direction (i.e. atoms flying nearly parallel to the cell windows) is enhanced
thanks to their longer interaction time with laser field [1]. Due to this atomic velocityselectivity,
the observed linewidth of the EIT resonance is more than by an order
narrower than that expected from the inverse of the window-to-window flight time of
the atoms. Meanwhile, direct influence of atom-wall collisions on the EIT resonance is
well seen when there is a large detuning of the coupling laser with respect to resonance
transition (EIT linewidth for this case achieves ~100 MHz). The slight dependence of
the EIT linewidth for the case when coupling frequency is resonant with atomic
transition allows us to detect EIT resonance (<20 MHz) at the smallest thickness
reported up to now L= 0.75 λ = 585 nm.
References
[1] Y. Pashayan-Leroy, C. Leroy, A. Sargsyan, et. al., JOSA B, 24, 1829 (2007).
[2] A. K. Mohapatra, T. R. Jackson, C. S. Adams, Phys. Rev. Lett. 98, 113003 (2007)
CP 167
189
Saturation effects of Faraday rotation signals in Cs vapor nanocells:
thickness-dependent effects
A. Sargsyan1, D. Sarkisyan1, A.Papoyan1,Y. Pashayan-Leroy1,2, C.Leroy2,
P. Moroshkin3 and A. Weis3
1Institute for Physical Research, NAS of Armenia, Ashtarak-2, 378410, Armenia
2Laboratoire de Physique de l’Université de Bourgogne, CNRS-UMR 5027, Dijon, France
3Départment de Physique, Université de Fribourg, 1700 Fribourg, Switzerland
Magneto-optical effects, in particular the nonlinear Faraday rotation (NFR), have proven to
be powerful tools in the laser spectroscopy of atomic gases. Optical magnetometers based
on ultra-narrow spectral features accompanied by a strong polarization rotation are under
active development. Ordinary cm-sized alkali metal cells are basic elements of such types
of optical magnetometers [1]. Recently, differences of the resonant absorption and
fluorescence spectra on the D2 line (λ =852 nm) of Cs vapor were demonstrated [2] when
exciting the transition either in a cell of L=λ/2 thicknesses and a L=λ cell.
Here we present experimental and theoretical results of NFR signals for thicknesses
L=λ/2 and L=λ performed on the D1 line λ =894 nm of Cs vapor. The nanocell was placed
inside Helmholtz coils and a crossed polarizer geometry was used. The beam of a
frequency-tunable DFB diode laser (λ = 894 nm, spectral width γL ~ 6 MHz) irradiated the
nanocell under an angle close to the normal in resonance with the D1 line of Cs. Signals
recorded with different laser intensities were compared. The magnetic field B was applied
along the laser propagation direction and could be varied in the range of 1-20 G. Spectra of
the NFR signal and absorption spectra for L=λ/2 and L=λ were compared.
There are two main features: i) significant differences were observed between the
NFR signal at L=λ/2 (~450 nm) and at L= λ. In the L=λ/2 cell, the Dicke-narrowed
absorption profile causes a stronger nonlinear Faraday rotation than in the L= λ (while in an
ordinary cm-sized cell a length increase leads to increase of the NFR signal), accompanied
by a significant spectral narrowing down to 20 MHz. ii) at relatively high intensities (>10
mW/cm2) the spectrum of the NFR signal for L= λ /2 simply broadens, while for L= λ, the
NFR signal vanishes completely due to strong optical-pumping. The different behaviors for
L= λ /2 and L= λ is more pronounced in the NFR signals than in the absorption spectra. A
theoretical model taking optical pumping effects into account gives a good agreement with
the experiment.
A simple magnetometer based on the NFR signal in a nanocell with L= λ/2 could be
developed. A sensitivity of several tens of mG is expected together with a spatial resolution
in the nanometer range was achieved. This may prove useful for measurements of strongly
inhomogeneous magnetic fields.
References
[1] D.Budker, W.Gawlik, D.Kimball, S.Rochester, V.Yaschuk, A.Wies, Rev. Mod. Phys.
74, 1153 (2002) and reference therein.
[2] C. Andreeva, S. Cartaleva, L. Petrov, S. M. Saltiel, D. Sarkisyan, T. Varzhapetyan, D.
Bloch, M. Ducloy, Phys. Rev. A 76, 013837 (2007) and reference therein.
CP 168
190
Magneto-optical resonances in atomic rubidium at
D1 excitation in ordinary and extremely thin cells
L. Kalvans1, M. Auzinsh1, R. Ferber1, F. Gahbauer1,
A. Jarmola1, A. Papoyan2, D. Sarkisyan2
1Laser Centre of the University of Latvia, 19 Rainis Boulevard, LV-1586, Riga, Latvia
2Institute for Physical Research, NAS of Armenia, Astarak-0203, Armenia
We present the results of a detailed experimental and theoretical investigation of nonlin-
ear magneto-optical resonances at D1 excitation of atomic rubidium in both ordinary and
extremely thin vapor cells. These sub-natural linewidth resonances have been known for
some time [1,2] and continue to be the subject of intriguing investigations and a valuable
tool for ne-tuning theoretical models [3]. In this work, magneto-optical resonances are
observed in both cells and can be bright or dark, depending on which hyper ne transition
is excited. However, in a normal cell individual hyper ne transitions cannot be resolved
because of Doppler brodening. The use of extremely thin cells (ETCs) represents a rather
new experimental technique and allows the experimenter to realize direct sub-Doppler
spectroscopy [4]. The thickness of the cell L used in this study varies in the range from
150 nm to 1600 nm. By comparing results obtained from both cells, one obtains use-
ful information about how Doppler broadening in uences the shape and contrast of the
resonances.
In this study experimental results from an ordinary Rb vapor cell and an ETC lled
with Rb are compared to theoretical calculations based on the optical Bloch equations,
which have proven to be well suited to describe the signals obtained in ordinary vapor
cells [3]. The vapor cells were placed inside a three-axis Helmholtz coil system and excited
with a diode laser manufactured by Toptica, GmbH. The polarization of the exciting laser
radiation was perpendicular to the magnetic eld, which was scanned, and the uorescence
was observed in the direction along the magnetic eld. In order to test how well our model
can describe ETC behavior, we study resonances at di erent laser powers, beam cross-
sections, and wall separations L, and compare the experimental measurements with the
results of calculations based on the model. By requiring the model to take into account
so many di erent parameters, it will be possible to either validate the model as is for
the case of the ETC or to identify new e ects that should be taken into account when
modelling the signals obtained with ETCs.
We acknowledge support from the Latvian National Research Programme in Material
Sciences Grant No. 1-23/50, the University of Latvia grant Y2-ZP04-100, the ERAF grant
VPD1/ERAF/CFLA/05/APK/2.5.1./000035/018, and the INTAS projects 06-1000017-
9001 and 06-1000024-9075. A. J., F. G., and L. K. acknowledge support from the ESF
project.
References
[1] R. W. Schmieder et al., Phys. Rev. A 2, 1216 (1970)
[2] G. Alzetta, A. Gozzini, L. Moi, and G. Orriols, Il Nuovo Cimento B 36, 5 (1976)
[3] M. Auzinsh et al., arXiv:0803.0201v1 [physics.atom-ph]
[4] D. Sarkisyan, D. Bloch, A. Papoyan, and M. Ducloy, Opt. commun. 200, 201 (2001)
CP 169
191
Frequency-modulation spectroscopy of coherent
population trapping resonances
A.Yu. Samokotin1, A.V. Akimov1, N.N. Kolachevsky1, Yu.V. Vladimirova2,
V.N. Zadkov2, A.V. Sokolov1, V.N. Sorokin1
1P. N. Lebedev Physical Institute,
Leninsky pr., 53, 119991 Moscow, Russia
2International Laser Center and Faculty of Physics,
M.V. Lomonosov Moscow State University,
199899 Moscow, Russia
E-mail: samokotin@gmail.com
Resonance of coherent population trapping (CPT) is one of nonlinear effects in three-level
atomic systems in so-called Λ-configuration. The resonance appears when a bichromatic
optical field with certain frequency and phase correlations between its components is
applied to the system. The ultimate spectral width of the CPT resonance is determined
by the coherency time between the lower levels of the Λ-system and can amount to several
tens of hertzs. A high Q-factor of CPT resonances enables to use them as frequency
references and in magnetometry.
One of the simplest experimental methods to create two phase-correlated light fields is a
frequency modulation (FM) of a monochromatic light field. In the case of diode laser, the
FM of light is achieved via modulation of the injection current.
In this work we experimentally investigated CPT resonances on Zeeman sublevels of 87Rb
D1-line excited by FM-modulated laser field and considered possible applications to magnetometry.
The laser was tuned to F = 2 → F = 1 transition, such that a chain of three
Λ-systems can be excited by the sidebands of the field. The FM field contains a number
of harmonics which relative amplitudes depend on modulation parameters, and thus a
number of CPT resonances of different amplitudes are excited at corresponding frequencies.
The experimental results are confirmed by the recent theoretical consideration of
FM spectroscopy of CPT resonances [1,2].
Since the frequency of the CPT resonance depends on magnetic field, the FM spectroscopy
allows to measure magnetic field applied to the Rb vapors. We recorded a number of CPT
resonances in two Rb cells (with and without buffer gas) at different values of an external
magnetic field. Our experimental setup allows to measure magnetic fields in the range
10-100 G with 0.05% accuracy. Non-linear Zeeman effect, playing a significant role in
such fields, is studied in details.
References
[1] J. Vladimirova et al., Laser Physics Lett., 3(9), 427-436 (2006).
[2] Yu.V. Vladimirova et al., J. of Theor. and Exp. Phys., 96, 629 (2003).
CP 170
192
Pump-probe spectroscopy:
a survey of the spectra for four polarization
combinations in degenerate two-level atoms
K. Dahl, L. Spani Molella, R.-H. Rinkleff, and K. Danzmann
Albert-Einstein-Institut, Max-Planck-Institut f¨ur Gravitationsphysik and
Institut f¨ur Gravitationsphysik, Leibniz Universit¨at Hannover
Callinstrasse 38, D-30167 Hannover, Germany
E-mail: rolf-hermann.rinkleff@aei.mpg.de
The optical properties of a cesium atomic beam driven on a resonant hyperfine transition
in the D2 line were experimentally investigated as a function of the probe-laser frequency.
In the present experiment the coupling laser drove the hyperfine transition 6s 2S1/2, F=4
— 6p 2P3/2, F=5 and was actively locked to it by means of frequency modulation spectroscopy.
The probe-laser frequency was scanned around the same transition [1]. The
coupling and probe absorption spectra were measured also in a range of probe-laser intensities
large enough to affect the pump-laser absorption. We present an experimental
survey of the coupling and probe absorption spectra for four polarization combinations
( +, , − , − +).
For all polarization combinations the probe-laser absorption profiles showed electromagnetically
induced absorption (EIA), a spectrum characterized by a peak on the ordinary
absorption profile. The observed coupling-laser absorption profiles could be described by
“absorption within transparency”, i.e. the absorption in the region around the two-photon
resonance was smaller than the absorption corresponding to the one-photon transition induced
by the coupling laser, and at the two-photon resonance an extra absorption peak
on this curve was measured.
For investigations with laser beams of counterrotating circular polarizations ( − +) the
coupling-laser absorption profiles showed at various laser powers a surprising behavior as
function of the laser powers. We detected a transition of the two-photon resonance peak
from absorption to more transparency when the probe-laser exceeded the constantly held
coupling-laser power [2]. Furthermore, a switch was observed for a constant probe-laser
power when varying the coupling-laser power. In all these cases the probe-laser absorption
profiles showed EIA signals. These findings are the experimental confirmation of
published theoretical predictions [3]. However, for phase measurements, no corresponding
switch from positive to negative parametric dispersion or from negative to positive
dispersion was observed.
The work was supported by the grant SFB407 of the Deutsche Forschungsgemeinschaft.
References
[1] L. Spani Molella, R.-H. Rinkleff, K. Danzmann, Appl. Phys. B 90, 273 (2008)
[2] K. Dahl, L. Spani Molella, R.-H. Rinkleff, K. Danzmann, Optics Letters (in press)(2008)
[3] C. Goren, A. D. Wilson-Gordon, M. Rosenbluh, H. Friedman, Phys. Rev. A 69, 053818
(2004)
CP 171
193
Dark resonance narrowing
in uncoated rubidium vacuum vapor cell
Z. Gruji¶c, M. Mijailovi¶c, D. Arsenovi¶c, M. Radonji¶c and B. M. Jelenkovi¶c
Institute of Physics
Pregrevica 118, Belgrade-Zemun, Serbia
E-mail: zoran.grujic@phy.bg.ac.yu
The CPT (Coherent Population Trapping) phenomena has been intensely investigated due
to its narrow resonance suitable for precision measurements, magnetometry and atomic
clocks etc. Di®erent approaches were applied in order to make these resonances narrower
in alkali vapor cells: coated cells in order to preserve atomic coherence after collision with
the cell wall, use of bu®er gas cells to increase atom time of °ight through laser beam,
and nanocells.
In our experiment we use spatially separated pump and probe laser beams in order to
induce Ramsey type CPT narrowing [1]. The probe laser beam (diameter of 1.5 mm) is
placed in the center of pump beam which has a ring like pro¯le. Outside diameter of the
pump laser beam is very close to the Rb cell diameter of 25 mm, while its inner is larger
then the probe laser diameter. Booth pump and probe laser beams are obtained from a
single ECDL (External Cavity Diode Laser), locked to the Fg = 2 ! Fe = 1 transition at
D1 line of 87Rb. Thus, some Rb atoms are ¯rst pumped into the dark state by the pump
laser beam, then travel through the \dark region" between the pump and the probe beam
before they reach the pump laser beam. The dark state and induced Zeeman coherences
created by pump are experimentally detected in the probe beam absorption. Related work
has been published by A. S. Zibrov and A. B. Matsko [2]. Obtained narrow resonances
widths, shapes depend of "dark region" length and pump and the probe laser intensities.
Our theoretical model relays on solving time-dependent optical Bloch equations and takes
into account di®erent atomic velocities and angles of atom propagation in respect to the
laser beams. It is shown that experiment and theory are in a good agreement for di®erent
probe and pump beam polarizations and intensities.
References
[1] Z.D. Gruji¶c, M.M. Mijailovi¶c, B.M. Pani¶c, M. Mini¶c, A.G. Kova·cevi¶c, M. Obradovi¶c,
B.M. Jelenkovi¶c and S. Cartaleva, Acta Physica Polonica A, No 5, 112, 799 (2007).
[2] A. S. Zibrov and A. B. Matsko, Physical Review A, 112, 013814
CP 172
194
Quantum search with trapped ions
S. Ivanov, P. Ivanov and N. Vitanov
Department of Physics, So¯a University, James Bourchier 5 blvd, 1164 So¯a, Bulgaria
We propose an ion trap implementation of Grover's quantum search algorithm for an
unstructured database of arbitrary length N. The experimental implementation is ap-
pealingly simple because the linear ion trap allows for a straightforward construction, in a
single interaction step and without a multitude of Hadamard transforms, of the re°ection
operator, which is the engine of the Grover algorithm. Consequently, a dramatic reduc-
tion in the number of the required physical steps takes place, to just O(
p
N), the same
as the number of the mathematical steps. The proposed setup allows for demonstration
of both the original (probabilistic) Grover search and its deterministic variation, and is
remarkably robust to imperfections in the register initialization.
CP 173
195
The observability of atoms
Gebhard von Oppen
Institut f¨ur Optik und Atomare Physik, Technische Universit¨at Berlin
Atomic particles differ fundamentally from macroscopic objects. In every measurement
with moderate spatial resolution, macroscopic objects can be observed continuously. Free
atoms, however, are observed discontinuously. Their observation is based on discrete,
spontaneously occurring elementary events, which can be counted. During free flight,
atoms are principally unobservable. As a consequence, identical atomic particles are
indistinguishable, whereas macroscopic twin-bodies can be distinguished [1, 2].
In this contribution I’ll show you that the difference in observability provides the key
for an experimentally oriented understanding of the ”spooky” phenomena of quantum
dynamics and of the appearance of chance in physics. In particular, I’ll consider:
1. The presence of statistical and thermal noise in all measurements: Noise is neglected in
classical dynamics (mechanics and electrodynamics), but justifies the concept of chance
in statistical thermodynamics. Accordingly, classical dynamics describes only reversible
processes, whereas statistical thermodynamics also applies to irreversible processes.
2. The transition from quantum to classical physics: Quantum dynamics is not a generalization
of classical dynamics, but describes an idealization of nature opposite to the
ideal of classical dynamics. The two theories apply to opposite extremes on a scale of
observability [2].
3. Space-time reality: ”...we have to abandon the description of atomic events as happenings
in space and time” (Einstein, Infeld: The evolution of physics). A description
in space and time is only justified for objects, which can be observed continuously, but
not for atomic particles. Therefore, atoms must not be idealized as mass-points, and a
thermodynamic ensemble of free atoms is fundamentally different from the mechanical
model of the ideal gas [3].
4. The approaches of physics to nature: The objects of physics must be observable.
Otherwise they cannot be investigated experimentally. For being observable, the objects
must be coupled spontaneously to the environment. This spontaneous coupling prohibits
an exact reproducibility of experiments. As a consequence of this insufficiency on the
experimental side, theory cannot image nature exactly, but describes idealizations of
nature. Presently, physics is based on three idealizations: Classical dynamics, statistical
physics and quantum dynamics.
5. From decomposition to isolation: The objects of classical dynamics can be decomposed.
But by decomposing, one produces components, which are not any more observable continuously.
One ultimately obtains the isolated objects of quantum dynamics[1].
References:
[1] G. v. Oppen, Physics Uspekhi 39, 617 (1996)
[2] G. von Oppen, Eur. Phys. J. Special Topics 144, 3 (2007)
[3] Bergmann, Schaefer, Lehrbuch der Experimentalphysik, Band 1 (12. Auflage, 2009),
in print
CP 174
196
Characterization of a High Precision Cold Atom
Gyroscope
T. Leveque, A. Gauguet, W. Chaibi and A. Landragin
LNE-SYRTE, CNRS UMR 3630, Observatoire de Paris
61 avenue de l'Observatoire, 75014 Paris, France
E-mail : thomas.leveque@obspm.fr
We investigate the limits of our inertial sensor using a cold atom interferometer. In
contrast with previous atomic setups, emphasis was placed on the long term stability and
compactness of the device thanks to the use of laser cooled atoms. Moreover it has been
designed to give access to all six axes of inertia (three accelerations and three rotations)
[1]. The expected improvement in stability will enable to consider applications in inertial
navigation, geophysics and tests of general relativity.
Caesium atoms are loaded from a vapour into two independent magneto-optical traps for
140 ms. Two caesium clouds are then launched into two opposite parabolic trajectories
using moving molasses at 2.4 m:s􀀀1, with an angle of 8 with respect to the vertical
direction. At the apex of their trajectory, the atoms interact successively with three
Raman laser pulses, which act on the matter-wave as beam splitters or mirrors, and
generate an interferometer of 80 ms total interaction time. The use of two atomic sources
allows discrimination between the acceleration and rotation.
The sensitivity to acceleration is 5; 5 10􀀀7m:s􀀀2 at one second, limited by residual
vibration on our isolation platform. Concerning the rotation, the sensitivity is 2; 3
10􀀀7rad:s􀀀1 at one second, limited by the quantum projection noise in the detection. After
1000 seconds of integration time, we achieve a sensitivity of 1 10􀀀8rad:s􀀀1. Moreover,
we have performed studies of all possible sources of drift on the rotation signal. Among
others, we measured the e ect of the two photon light shift during the Raman laser pulses.
We also identi ed the main limit of the stability, which is linked to uctuations of the
atomic trajectories inducing Raman laser wave-front changes.
We characterize the accuracy of our gyroscope in term of bias and scaling factor. In
this purpose, we record rotation phase shift as a function of the interrogation time and
rotation rate. The rotation shift behaves as the square of the interrogation time and
linearly with the projection of the Earth's rotation rate, which is modulated by turning
the interferometer in the horizontal plane. The linearity of our sensor was demonstrated
with an agreement better than 0.01% and the bias was determined with an accuracy of
5 10􀀀8rad:s􀀀1. Currently, we are developing a new method to enable measurements in
noisy environments which will be crucial for applications in the eld of inertial navigation.
References
[1] B. Canuel, F. Leduc, D. Holleville, A. Gauguet, J. Fils, A. Virdis, A. Clairon, N.
Dimarcq, Ch.J. Bord e, and A. Landragin, "Six-Axis Inertial Sensor Using Cold-Atom
Interferometry", Phys. Rev. Lett. 97 010402 , 2006.
CP 175
197
CP 176
198
CP 177
199
Parametrization of NeI spectrum for 2p55g, 6g, 7g
configurations using semiempirical method
Anisimova G.P.1, Efremova E.A.1, Tsygankova G.A.1
1St.-Petersburg State University
Petergof, Ulianovskaja st., 1, NIIF-SPbSU, St.-Petersburg, 198504, Russia.
E-mail: efremovakat@inbox.ru
The paper presents results of numerical study of the fine structure parameters (the radial
integrals in the energy operator matrix) for 2p55g, 2p56g and 2p57g configurations of a
neutral Neon atom. The angle coefficients for the radial integrals were obtained taking
into account the following interactions in the Breit’s Hamiltonian: electrostatic, spin-orbit
(own and foreign), spin-spin and orbit-orbit [1].
The energy operator matrix for "hole" configurations can be calculated either using fractional
parentage coefficients or via free momentums representation. In the latter case it is
assumed that the atom’s state is described exclusively by the individual quantum numbers
of particular electrons. The energy operator matrix obtained via free momentum representation
was transformed to LSJM􀀀 and j1KJM􀀀representations. For vector types
of coupling the energy operator matrix has 24 matrix elements each of which is a linear
combination of 18 fine structure parameters.
The calculations are based on the empirical data namely the energies of the fine structure
experimentally obtained with the high precision [2; 3].
The classification of the fine structure levels for 2p55g, 2p56g and 2p57g of NeI was given
in jK-coupling representation. The calculation of the parameters is also accomplished
using the energy operator matrix given in jK-coupling representation. The numerical
calculation is based on the Newton’s method applied to the set of non-linear equations.
The unknowns for the equations were the parameters of the fine structure as well as the
expansion coefficients of wave functions in jK-coupling basis. The initial approximation
for Newton’s method was derived using least-squares method.
As a result of numerical study a set of the fine structure parameters was obtained. Substitution
of these parameters into the energy operator matrix and follow-up diagonalization
for all the coupling types yields the energies, which fully agree with the energies obtained
experimentally. Expansion coefficients for LS􀀀 and JK􀀀 basises, gyromagnetic ratio
and level compositions in LS􀀀basis were also obtained. It can be concluded that the
highly-excited 2p55g, 2p56g and 2p57g configurations of NeI are close to jK-coupling
model.
References
[1] Anisimova G.P., Efremova E.A., Tsygankova G.A., Vestnik of St.-Petersburg State
University. Series 4. Part 3., 49 (2007)
[2] Chang E.S., Schoenfeed W.G., Biemont E., Quinet P., Palmeri P., Phys. Scr. V. 49.,
26 (1994)
[3] Saloman E.B., Sansonetti C.J. Wavelengths, J. Phys. Chem. Ref. data. V. 33. N 4,
1113 (2004).
CP 178
200
Ab initio calculations of aluminium-like calcium
R. Karpu skien_e, P. Bogdanovich and O. Rancova
Institute of Theoretical Physics and Astronomy of Vilnius University
A. Go stauto st. 12, 01108 Vilnius, Lithuania
E-mail: olga@itpa.lt
This work presents theoretical investigation of Ca VIII ion of aluminium isoelectronic
sequence. The ab initio study of Ca VIII was performed within the con guration interac-
tion approximation in the basis of transformed radial orbitals with a variable parameter
[1]. Relativistic e ects were accounted for within the Breit-Pauli approximation.
The ground con guration 3s23p and excited con gurations 3s3p2, 3s23d, 3p3, 3s3p3d,
3s24s, 3s24p, 3s24d, 3s24f, 3s3p4s and 3s3p4p are studied. The rst calculation of energy
spectra was performed in the basis of admixed con gurations made by virtual excitations
from 3l- and 4l-shells. The second calculation was performed in the extended basis of
admixed con gurations made by the virtual excitations not only from 3l- and 4l- shells,
but also from the closed shells 2s- and 2p-. This way enables us to take into account core
polarization e ects.
The obtained energy spectra of ground con guration 3s23p and excited con gurations
3s3p2, 3s23d, 3p3 and 3s3p3d were compared with available data [2-3]. We supplement
our results with the energy spectra of highly excited con gurations 3s24s, 3s24p, 3s24d,
3s24f, 3s3p4s and 3s3p4p as well. The obtained energy levels of these con gurations
(except 3s24p and 3s3p4p) are compared with data from [4].
The comparison of the obtained results and the data presented by other authors show
that the core polarization is important and has a considerable in uence on the accuracy
of theoretical energy spectra.
The multicon guration wave functions determined as a result of the energy matrix diag-
onalization were used to calculate the wavelengths and the characteristics for the electric
dipole transitions from the excited con gurations. The radiative lifetimes of the excited
levels were also calculated and compared with the available data.
These calculations have been performed using the resources of the European Commission
project RI026715 BalticGrid and LitGrid project.
References
[1] P.Bogdanovich, R. Karpu skien_e, Lith. J. Phys. 39, 193 (1999)
[2] E. Landi, P.J. Storey, C.J. Zeippen, Astrophys. J. 607, 640 (2004)
[3] U.I. Safronova et al, Atomic Data and Nuclear Data Tables 84, 1 (2003)
[4] J. Sugar, C. Corliss, J. Phys. Chem. Ref. Data 14, Suppl. 2, 1 (1985)
CP 179
201
Isotope shifts of forbidden lines of Lead
T.J. W¸asowicz, S. Werbowy, R. Drozdowski, J. Kwela
Institute of Experimental Physics, University of Gdansk, ul. Wita Stwosza 57,
80-952 Gdansk, Poland
The 6s26p2 ground configuration of Pb I gives rise to five levels 1S0, 3P2,1,0 and 1D2. In
the 6s26p ground configuration of Pb II only two levels 2P1/2 and 2P3/2 appear. Since
electric-dipole (E1) transitions between the states of the same parity are forbidden, all
the levels of these configurations are metastable. In the second-order radiation theory
weak magnetic-dipole (M1), electric-quadrupole (E2) or mixed type (M1+E2) transitions
between these levels are permitted.
In the experiment the isotope shifts (IS) of forbidden lines 461.9 nm (6p2 1S0 → 6p2 3P1;
M1), 531.5 nm (6p2 1S0 → 6p2 3P2; E2), 733.2 nm (6p2 1D2 → 6p2 3P1; M1+E2) of Pb I
and 710.2 nm (6p 2P3/2 → 6p 2P1/2; M1+E2) of Pb II between four stable isotopes (204,
206, 207, 208) were measured. The observation of isotopic structure of multipole lines
is very difficult because of relatively small shifts (see Table 1) and the components of
the isotope structure are partly or completely unresolved. For such a case the computer
simulation technique becomes very useful. Such a computer technique has been recently
used by us in the analysis of the IS spectra of electric-dipole (E1) lines of Pb I [1] and Pb II
[2]. By variation of free parameters describing the line shape and positions of individual
components the calculated profiles were fitted into the recorded spectra. In the case of the
M1+E2 transitions the E2 admixtures (see e.g. [3]) were also taken into account as a fixed
parameter. Moreover, using the King plots we were able to separate the two contributions
to the total isotope shift, namely the mass and the field shifts. These results may prove
to be useful for future studies of PNC in Pb.
Table 1: Measured isotope shifts relative to the 208 isotope of lead (in mK).
Line (nm) Transition δν207CG,A
i δν206,A
i δν204,A
i
461.9 6p2 1S0→6p2 3P1 4.9 (1.1) 7.8 (1.3) 14.6 (3.4)
531.5 6p2 1S0→6p2 3P2 8.1 (1.5) 13.0 (1.2) 24.2 (5.4)
733.2 6p2 1D2→6p2 3P1 5.6 (0.6) 8.8 (1.0) 16.3 (2.4)
710.2 6p 2P3/2→6p 2P1/2 10.8 (1.9) 17.3 (2.3) 32.7 (5.6)
Acknowledgment
This work was supported by the University of Gdansk, grant BW 5200-5-0053-8.
References
[1] T.J. W¸asowicz, J. Kwela, Phys. Scr. 77, 025301 (2008)
[2] T.J. W¸asowicz, R. Drozdowski, J. Kwela, Eur. Phys. J. D 36, 249 (2005)
[3] T.J. W¸asowicz, Phys. Scr. 76, 294 (2007)
CP 180
202
Solid 4He stabilized by charged impurities below the
solidi¯cation pressure of pure helium
P. Moroshkin, V. Lebedev, A. Weis
University of Fribourg, Department of Physics, Fribourg, Switzerland
The coexistence of a 4He crystal with super°uid 4He is a model system for investigating
fundamental aspects of the growth and melting of crystals. Here we present a study of
a dramatic e®ect [1] that occurs during the melting of solid 4He doped with nanoscopic
impurities | alkali atoms, clusters, ions, and electrons: the doped part of the crystal
remains solid under conditions at which pure helium is liquid. We refer to this structure
as an iceberg. If the structure disintegrates in a static electric ¯eld of several kV/cm
fragments of the iceberg containing unequal amounts of electrons and positive ions move
towards either the positive or the negative electrode. These events are accompanied by
electric current pulses that have allowed us to determine the number density of charged
particles in the sample to be of order of 1014 ¡ 1015 cm¡3. We consider the iceberg as
being an aggregation of positively charged particles (snowballs) and electron bubbles.
Using interferometry we have found [1] that the density of the solid structure (iceberg)
lies between the densities of pure liquid and pure solid helium. On the other hand,
a comparison of laser-induced °uorescence spectra of neutral Cs atoms trapped in the
iceberg with those in bulk solid 4He indicates that the iceberg has the same density and
crystalline structure (bcc, hcp) as the bulk solid 4He. We therefore suggest that the
iceberg is in fact a porous structure ¯lled with liquid helium.
[1] P. Moroshkin, A. Hofer, S. Ulzega, A. Weis, Nature Physics 3, 786 (2007).
CP 181
203
Spectroscopy of Ba atoms isolated in solid He matrix
P. Moroshkin, V. Lebedev, A. Weis
University of Fribourg, Department of Physics, Fribourg, Switzerland
We present the results of a new spectroscopic study of Ba-doped solid 4He. Ba atoms
are introduced into the solid He matrix by means of laser ablation from a metallic target
surrounded by solid He. This allows us to produce a sample with up to 1015 Ba atoms per
cm3. By exciting the sample with a pulsed-laser tuned over 440 { 690 nm we have found
a number of °uorescence lines, some of which were not detected in earlier studies [1,2].
Our analysis shows that the Ba atoms are excited at the single-photon 6s2 1S0 ¡6s6p1P1
transition at 540 nm and at least at 6 di®erent two-photon transitions at 530, 568, 618,
632, 650, and 675 nm. The decay of highly excited states populated by the two-photon
transitions proceeds via a cascade of °uorescence transitions including triplet-triplet and
intercombination lines, as well as other so far unidenti¯ed lines.
We have also performed a systematic study of the absorption and °uorescence spectra
of the single-photon 6s2 1S0 ¡ 6s6p1P1 transition and their dependence on helium pres-
sure. The spectral line is blueshifted and broadened by the interaction with the matrix.
The shift and the broadening increase with the He pressure following the trend already
observed in pressurized liquid helium.
[1] H. Bauer, M. Beau, D. Friedl, C. Marshand, K. Miltner, H. J. Reyher, Phys. Lett. A
146, 134 (1990).
[2] S. I. Kanorsky, M. Arndt, R. Dziewior, A. Weis, T. W. HÄansch, Phys. Rev. B 49,
3645 (1994).
CP 182
204
New Measurement of the 2S Hyper¯ne Splitting in
Atomic Hydrogen
A. Matveev1;2, J. Alnis1, C. Parthey1, N. Kolachevsky1;2, T.W. HÄansch1;3
1 MPI fÄur Quantenoptik, Hans-Kopfermann Str. 1, 85748 Garching, Germany
2 P.N. Lebedev Physics Institute, Leninsky prosp. 53, 119991 Moscow, Russia
3 Ludwig-Maximilians University,Geschwister-Scholl-Platz 1, 80539 Munich, Germany
Recent advances in laser stabilization, optical frequency measurements and preparation of
cold atomic samples open possibility to compare optical frequencies to the 17th decimal
place [1] which signi¯cantly overcomes the accuracy of the best Cs fountain clocks de¯ning
the SI second [2]. Besides this impressive result there exist many other examples when
spectroscopy in the optical domain allows for more accurate measurements than classical
radio-frequency techniques.
In 2003 we have developed a new optical method for measuring the 2S hyper¯ne split-
ting in atomic hydrogen by help of two-photon spectroscopy of the 1S { 2S transition
[3]. By measuring the frequency di®erence between two optical ¯elds at 243nm driving
1S(F = 0) ! 2S(F = 0) and 1S(F = 1) ! 2S(F = 1) two-photon transitions in
a nearly-zero magnetic ¯eld one can derive the frequency of the 2S hyper¯ne splitting
fhfs(2S). Accurate experimental value fhfs(2S) allows for accurate tests of quantum
electrodynamics theory since the speci¯c di®erence D21 = 8fhfs(2S) ¡ fhfs(1S) can be
calculated with a high accuracy [4].
In 2008 we have remeasured the fhfs(2S) frequency using an ultra-stable vibrationally-
and temperature-compensated optical cavity as an optical frequency reference [5]. The
diode laser at 972nm locked to this cavity has a spectral line width of less than 0.5 Hz
while its frequency drift is on the level of 50 mHz/s. The excellent stability of this new
laser oscillator (the Allan deviation reaches 2 £ 10¡15 in less than 1 s) allows for accurate
measurement of the 2S hyper¯ne splitting.
The two photon transitions between di®erent hyper¯ne sublevels are excited by the second
harmonic of a dye laser [3], while its frequency is continuously compared to the frequency
of the second harmonic of the stabilized diode laser at 972 nm. The new measurement
possesses a signi¯cantly improved statistics which, in turn, allows for more detailed study
of systematic e®ects. The preliminary analysis of experimental data gives us a value
of fhfs(2S) = 177 556 840(5) Hz which uncertainty is about 5 times less than the most
accurate direct radio frequency measurement performed up to date [6].
[1] T. Rosenband et al., Science 319, 1808 (2008).
[2] S. Bize et al. J. Phys. B: At. Mol. Opt. Phys. 38 S44968, (2005).
[3] N. Kolachevsky, M. Fischer, S.G. Karshenboim, T.W. HÄansch, Phys. Rev. Lett. 92,
033003 (2004).
[4] S.G. Karshenboim and V.G. Ivanov, Phys. Lett. B 524, 259 (2002).
[5] J. Alnis, A. Matveev, N. Kolachevsky, Th. Udem, and T.W. HÄansch, arxiv:0801.4199.
[6] N.E. Rothery and E.A. Hessels, Phys. Rev. A 61, 044501 (2000).
CP 183
205
High Resolution Laser Spectroscopy of Scandium
Yu.P. Gangrsky1, K.P. Marinova1, S.G. Zemlyanoi1, M. Avgoulea2, J.Billowes2,
P.Campbell2, B. Cheal2, B. Tordo®2, M. Bissel3, D.H. Forest3, M. Gardner3, G.
Tungate3, J. Huikari4, H. Penttila4 and J. Aysto4
1FLNR Joint Institute for Nuclear Research, 141980 Dubna, Moscow Region, Russia
2Shuster Building, University of Manchester, Manchester M13 9PL, UK
3School of Physics and Astronomy, University of Birmingham, B15 2TT, UK
4Accelerator Laboratory, University of Jyvaskyla SF-405 51, Finland
Collinear laser spectroscopy experiments on the ScII transition 3d4s3D2 ! 3d4p 3F3 at
¸ ¼ 363.1 nm were performed on the 42¡46Sc isotopic chain using an ion guide isotope
separator with a cooler-buncher [1]. Hyper¯ne structure constants, nuclear moments,
isotope and isomer shifts of ¯ve ground states and two isomers, 44;45Sc, were measured.
Among the investigated nuclei the 45Sc isotope deserves closer attention because along
with several other odd-A nuclei in the lower 1f7=2 shell it has a positive parity isomeric
state with I¼ = 3/2+. Such excited states have been explained [2] in the framework of the
Nilsson model: the Nilsson 3/2+ orbital of the sd shell and the lowest orbital of the 1f7=2
shell approach each other for increasing deformation, thereby producing a low-lying well
deformed core excited state. The value of Q0 obtained from the laser spectroscopic data in
this work is nearly two times larger, than the one of [2]. The unusually large quadrupole
moment of the isomeric state of 45Sc is the most striking feature of the present data. This
surprising fact remains so far unexplained.
The preliminary analysis performed to date can only provide estimates of the expected
upper and lower limits of the radii changes. No drastic contradiction with the overall radii
trend in the f7=2 shell is found. While the odd-even staggering is reduced compared with
Ca and Ti, it is consistent with that observed in K, the only other odd-Z element studied
in this region. Although qualitative, the new information on Sc charge radii changes
constitutes a valuable contribution to the systematic of nuclear charge radii in the Ca
region.
1. Billowes J., Hyp. Int. 162 (2005) 63.
2. Styszen J. et al., Nucl. Phys. A 262 (1976) 317.
CP 184
206
CP 185
207
CP 186
208
VUV Spectroscopy of Xe IX
H.P. Garnir, ´ E. Bi´emont, S. Enzonga Yoca and P. Quinet
Institut de Physique Nucl´eaire, Atomique et Spectroscopie
Universit´e de Li`ege
Sart Tilman B15, B4000 LIEGE BELGIUM
hpgarnir@ulg.ac.be
The spectrum of xenon ions has been recorded by the beam-foil method in the 10-110 nm
wavelength range and many lines of Xe VII-VIII have been analysed [1]. In our spectra,
we have looked for lines belonging to 8 times ionized Xe. Some of the lines attributed to
Xe IX have been pinpointed by a careful analysis of the line intensity variation with the
beam energy [2]. For those lines, the lifetimes of the upper level have been measured by
analyzing beam-foil decay curves (one of the rare methods able to provide experimental
data in these multicharged ions).
Our measurements will be compared with theoretical values calculated by a relativis-
tic Hartree-Fock approach including core-polarization effects and by a purely relativistic
multiconfiguration Dirac-Fock method.
During the meeting, we will describe our experiment and present our new results.
References
[1] ´ E. Bi´emont, M. Clar, V. Fivet, H.-P. Garnir, P. Palmeri, P. Quinet, and D. Rostohar,
Eur. Phys. J. D 44, 23 (2007)
[2] H.P. Garnir, Journal of Physics: Conference Series, accepted for publication
CP 187
209
Improved atomic data for platinum group elements
V. Fivet1, ´E. Bi´emont1,2, P. Palmeri1, P. Quinet1,2, L. Engstr¨om3, H. Lundberg3
and H. Nilsson4
1 Astrophysique et Spectroscopie, Universit´e de Mons-Hainaut, B-7000 Mons, Belgium
2 IPNAS, Universit´e de Li`ege, Sart Tilman, B-4000 Li`ege, Belgium
3 Department of Physics, Lund Institute of Technology, PO Box 118,
SE-22100 Lund, Sweden
4 Lund Observatory, Lund University, PO Box 43, SE-22100 Lund, Sweden
E-mail: vanessa.fivet@umh.ac.be
The spectra of the elements situated in the sixth row of the periodic table (72<Z<86) are
still poorly known due to the lack of laboratory analysis and to the complexity of their
electronic configurations of the type 4f145dNnl and 4f145dN−1nln0l0 (N=3−10, nl, n0l0=6s,
6p, 6d, ...).
The aim of the present work is to provide a large amount of new atomic data for neutral
and lowly ionized sixth row elements. The astrophysicists need these accurate data for
refining their models in nucleosynthesis, for determining the chemical composition of CP
stars, for the diagnostic of plasmas and for cosmochronology. Radiative parameters for
some of these elements are also strongly needed for research oriented toward controlled
thermonuclear fusion.
In the present work, radiative lifetimes of selected sixth row ions have been measured
using TR-LIF spectroscopy[1] developed at the Lund Laser Centre by Prof. Svanberg and
his group. The new results have been used to assess the accuracy of calculations performed
with a Hartree-Fock-plus-Relativistic-corrections model that takes configuration
interaction and core-polarization effects into account[2,3].
By combining experimental lifetimes and theoretical branching fractions, we have determined
new oscillator strengths and transition probabilities. We will discuss the results
obtained for the following ions: Ta III (Z=73), W II, W III (Z=74) et Pt II (Z= 78).
These results will be stored in the database DESIRE (DatabasE on SIxth Row Elements)
[4,5] on a website of the University of Mons-Hainaut.
References
[1] H.L. Xu , A. Persson, S. Svanberg, K.B. Blagoev, G. Malcheva, V. Penchev and ´E.
Bi´emont, Phys. Rev. A 70, 0425058 (2004)
[2] R.D. Cowan, The Theory of Atomic Structure and Spectra, University of California
Press, Berkeley (1981)
[3] P. Quinet, P. Palmeri, ´E. Bi´emont, M.M. McCurdy, G. Rieger, E.H. Pinnington, M.E.
Wickliffe and J.E. Lawler, Mon. Not. R. Astron. Soc. 307, 934 (1999)
[4] V. Fivet, P. Quinet, P. Palmeri, ´E. Bi´emont and H.L. Xu, J. Electron. Spectrosc.
Relat. Phenom. 156-158, 250 (2007)
[5] http:\\www.umh.ac.be\ astro\desire.shtml
CP 188
210
Impact of high-order moments on the statistical
modeling of transition arrays
F. Gilleron1, J.C. Pain1, J. Bauche2 and C. Bauche-Arnoult2
1Commissariat a l'Energie Atomique, Centre DAM ^Ile-de-France, Bruy eres-le-Ch^atel,
91297 Arpajon Cedex, France
2Laboratoire Aim e Cotton, CNRS II, B^atiment 505, 91405 Orsay, France
The impact of high-order moments on the statistical modeling of transition arrays in
complex spectra is studied [1]. It is shown that a departure from the Gaussian, which
is usually employed in such approach, may be observed even in the shape of unresolved
spectra due to the large value of the kurtosis coe cient. The use of a Gaussian shape
may also overestimate the width of the spectra in some cases. Therefore, it is proposed
to simulate the statistical shape of the transition arrays by the more exible generalized
Gaussian distribution which introduces an additional parameter - the power of the argument
in the exponential - that can be constrained by the kurtosis value. The relevance
of the new statistical line distribution is checked by comparisons with smoothed spectra
obtained from detailed line-by-line calculations. The departure from the Gaussian is also
con rmed through the analysis of 2p ! 3d transitions of recent absorption measurements
[2-4]. A numerical t is proposed for an easy implementation of the new statistical pro le
in atomic-structure codes.
[1] F. Gilleron, J. C. Pain, J. Bauche and C. Bauche-Arnoult, Phys. Rev. E 77, 026708
(2008)
[2] C. Chenais-Popovics et al., Astrophys. J. Suppl. Ser. 127, 275 (2000).
[3] J. Bruneau et al., Spectral Opacity experiments, (Symposium Science on large lasers,
Saclay, 1997).
[4] J. E. Bailey et al., J. Quant. Spectrosc. Radiat. Transfer 81, 31 (2003).
CP 189
211
Exact and statistical methods for computing the
distribution of states, levels and E1 lines in atomic
spectra
J.C. Pain and F. Gilleron
Commissariat a l'Energie Atomique,
Centre DAM ^Ile-de-France, Bruy eres-le-Ch^atel, 91297 Arpajon Cedex, France
We propose di erent methods in order to determine the distribution P(M) of quantum
states M (projection of total angular momentum J) inside a relativistic or non-relativistic
con guration. This distribution is used to calculate: (i) the distribution of levels [1] of a
con guration and (ii) the number of electric-dipolar (E1) lines between two con gurations.
First, an e cient recursive approach is presented for an exact calculation of P(M) [2].
Second, the statistical approach of Bauche et al. [3] is improved to account for high-l
spectators (e.g. i1pN) which occur for instance in electron capture into high-lying Rydberg
states in collisions between multiply charged ions and light target gases [4]. In that case,
P(M) may exhibit a plateau, which can neither be modeled by a Gaussian nor by a
Gram-Charlier expansion series. We show that the Generalized Gaussian, which exponent
is completely determined by the kurtosis (reduced fourth-order centered moment) 4 of
P(M), is more suited for such cases. We propose an analytical formula for the evaluation
of the number of E1 lines with a larger range of applicability.
[1] E. U. Condon and G. H. Shortley, The Theory of Atomic Spectra (Cambridge: Cambridge
University, 1935).
[2] F. Gilleron and J. C. Pain, to be published.
[3] J. Bauche and C. Bauche-Arnoult, J. Phys. B: At. Mol. Phys. 20, 1659 (1987).
[4] P. Hvelplund, H. K. Haugen, H. Knudsen, L. Andersen, H. Damsgaard and F. Fukusawa,
Phys. Scr. 24, 40 (1981).
CP 190
212
Laser optogalvanic spectroscopy of Lanthanum in
Spectral range of Rhodamine 6G.
Nighat Yasmin, R Islam
Laser Development Division, National Institute of Lasers and Optronics Nilore
Islamabad
Hyper ne structure studies of some of the allowed transitions of La I has been carried out
by high resolution Doppler limited laser optogalvanic spectroscopy. A narrow bandwidth
(500 KHz) Autoscan ring dye laser (899-29) pumped by argon ion laser model Innova
series 200 ( coherent Corp) has been employed to investigate the hyper ne structure in
the wavelength range 5600-6200 A of Rhodamine 6G in connection with a commercially
available hollow cathode. Sixteen transitions of La I have been observed involving twenty
ve levels, twelve with odd and thirteen with even parity. A comparison with the previous
data available in the literature has also been made.
The recorded spectra were analyzed using Casimir's formula which yields the expression
for the shift of a hyper ne component from the center of the gravity. Then we formulate
four simultaneous equations for the four unknown quantities A, B, A0 and B0 according
to the expression. i.e;
12 = AK1􀀀K2
2 + 3B
8
[K1(K1+1)􀀀K2(K2+1)]
IJ(2I􀀀1)(2J􀀀1)
+A0K0
1 􀀀K0
2
2 + 3B0
8
h
K
0
1

K
0
1+1

􀀀K
0
2

K
0
2+1
i
IJ0(2I􀀀1)(2J0􀀀1)
A computer program based on Gauss elimination technique is then employed to determine
the hyper ne structure constants i.e. A, B, A0 and B0 for lower and upper energy levels.
The curve obtained through the utilization of these empirically evaluated hyper ne struc-
ture constants is then matched with the experimental data through another computer
program for the best- t values.
Here we present the analyzed data of only few transitions. Experimentally obtained
hyper ne structure constants (in MHz) of these transitions along with the tranisition
wavelengths are shown below.
Lower level Upper level
A
E(cm􀀀1) Con g. Term J A B E (cm􀀀1) Con g. Term J A B
5677.707 2668.2 5d2(3F)6s 4F 3/2 -487.3 62.88 20338.3 5d2(3F)6p 4F 3/2 254.8 97.63
5690.6 0.00 5d6s2 2D 3/2 141.2 44.78 17567.49 5d6s(3D)6p 4P 1/2 2892.1 0.00
5699.241 13747.28 3d3 4F 9/2 -63.8 -26.2 31287.646 5d6s(3D)7s 4D 7/2 -565.5 800
5699.348 4121.572 5d2(3F)6s 4F 9/2 489.5 32.18 21662.51 5d2(3F)6p 2G 7/2 283.5 55
5720.009 3494.58 5d2(3F)6s 4F 7/2 461.3 21.6 20972.22 5d2(3F)6p - 5/2 -65,74 37.42
5742.922 7231.36 5d2(3P)6s 4P 1/2 2460.0 0.00 24639.27 5d2(3P)6p 4S 3/2 -197.3 26.0
5744.384 7679.94 5d2(3P)6s 4P 5/2 798.5 826.6 25083.42 5d2(3P)6p 4D 7/2 67.5 820.2
5821.975 9960.96 5d2(1G)6s 2G 7/2 -289.2 72.40 27132.5 5d2(1G)6p 2G 7/2 69.1 42.6
5829.692 7490.46 5d2(3P)6s 4P 3/2 936 37.6 24639.27 5d2(3P)6p 4S 3/2 -221 -140
5845.034 1053.2 5d6s2 2D 5/2 182.1706 54.213 18157.0 5d6s(3D)6p 4P 5/2 651.5 115
CP 191
213
Investigation of the even parity states of group II-B
elements (Zn, Cd and Hg)
Ali Nadeem
Photonics Division, National Institute of Lasers and Optronics (NILOP), Islamabad,
Pakistan
Systematic studies of the group-IIB (Zn, Cd, Hg) elements have been carried out to
investigate highly excited even-parity triplet states. The inter-combination msnp 3P1
levels of these atoms can be populated relatively easily using ultra violet laser light and
can serve as intermediate levels. The lack of spectroscopic studies on the bound states
of these atoms is primarily due to the fact that their ionization potentials lies in the
VUV region. As already said, their resonance transitions lie in the UV region (Cd,
Zn) and in the VUV region (Hg). Consequently, multi-photon and multi-step ionization
techniques have not been employed so far to probe the highly excited states of these atoms.
The experimental set-up comprised of two frequency doubled dye lasers simultaneously
pumped by a common Q-switched Nd:YAG (532nm; 355nm) laser operating at 10Hz
repetition rate and 7ns pulse duration. To record the spectra, a thermionic diode ion
detector working in the space charge limited mode was used. The change in the diode
current due to the photo-ion production was measured as a voltage drop across a 100 kΩ
load resistor.
The new observations for cadmium include the term energies and quantum defects of 5snd
3D2 (11 < n < 52) and 5sns 3S1 (12 < n < 38) Rydberg series whereas the 5snd 1D2
series have been detected from n = 11 to 26. The appearance of 5snd 1D2 is because
the Δ S = 0 selection rule is relaxed, then triplet to singlet transitions are observable.
The ratio of the transition probabilities in cadmium indicates that the 1P1 contribution
to the 3P1 wave function is 0.2%, whereas in zinc it is 0.02% and in mercury it is 3.2%.
The singlet-triplet mixing determines the intensities of the excited triplet states. The
relative intensities of the excited states have been described according to electric dipole
selection rules. The first ionization potential of cadmium has been determined from
the unperturbed 5snd 3D2 series. From the termination of the Rydberg series we have
estimated the net electric field present in the interaction region using the E(V/cm) =
1.23 x 109 n5
m relation. During experiments on zinc the two metastable levels 4s4p 3P0
and 4s4p 3P2 also get populated through collisions. The average thermal energy of atoms
corresponding to 823K is 572cm−1 which is sufficient to populate these fine structure
components in zinc. New observations include 4snd 3D2 (14 < n < 55) and 4sns 3S1 (15
< n < 35) Rydberg series excited from the 4s4p 3P1 level. In addition, 4snd 3D3 (13 < n
< 49) and 4snd 3D1 (10 < n < 20) series including few members of the 4sns 3S1 series were
also observed exciting the 4s4p 3P0 and 4s4p 3P2 states, respectively. The wave function
mixing in zinc is very small therefore no singlet transitions are detected. In mercury we
have observed the even-parity 6snd 3D2 (25 < n < 52) series and few levels of the 6sns
3S1 series. Although the wave function mixing of the 1P1 and 3P1 is much higher than for
Cd and Zn and thus the 6snd 1D2 series should be present with high intensity compared
to that in zinc and cadmium, these series is completely absent in the spectra of mercury.
CP 192
214
New levels of Pr I dicsovered via infrared spectral
lines
Z. Uddin1, L. Windholz1, F. Akber2, M. Jahangir2, I. Siddiqu1
1Institute of Experimental Physics, Technical University of Graz, Austria
2Department of Physics, University of Karachi, Pakistan
The Fourier transform (FT) spectrum of Praseodymium [1] shows hundreds of spectral
lines in the infrared and far infrared region, many of them are unclassi ed. We have
classi ed lot of them by their hyper ne (hf) structures and level energy di erences. Still
we found a number of lines, which could not be explained as transitions between known
levels; this indicated that up to now unknown energy levels of Pr are involved. Some of
the hyper ne structures in the FT spectrum have a very good signal to noise ratio, thus
a t of these structure was possible. In this way we found 15 new levels of Pr I. For one
of them we give the following details:
The line 8954.659 A is a line already classi ed [2] as a transition between the upper
level 31787 cm􀀀1 (J = 5.5, odd parity) and the lower level 20622.7 cm􀀀1 (J = 6.5 ,
even parity). However, the hf structure in the FT spectrum does not match with the hf
structure corresponding to this transition. A t of the hf structure suggested a transition
4.5 - 4.5 with hyper ne constant A of the lower level close to 810 MHz. With help of
this value we identi ed the lower level to be 11713 cm􀀀1, J = 4,5, even parity. Adding
the wave number of the line (center of gravity wavelength corrected to 8954.681 A), we
introduced a new upper level 22877 cm􀀀1, J = 4.5, odd parity. This new level of Pr
I explains 10 lines shining up in the FT spectra. Six of them were already known but
unclassi ed lines, three of them are new lines, one classi cation was wrong (see table).
From the line 5419.935 A we determined the nal value of the level energy, 22877.524
cm􀀀1, assuming that the energy 4432.24 cm􀀀1 of the lower level is correct.
Lines classi ed by new level 22877.524 cm􀀀1, J = 4.5, A = 932 MHz, odd parity:
Lower level with even parity
Wavelength ( A) J Energy (cm􀀀1) A (MHz) Remarks
5419.935 4.5 4432.24 929 unclassi ed line
6035.419 5.5 6313.25 756.3 unclassi ed line
6117.513 3.5 6535.52 979 unclassi ed line
7346.179 5.5 9268.75 976 new line
7714.313 3.5 9918.17 1057 unclassi ed line
8349.517 5.5 10904.07 301 new line
8825.330 4.5 11549.61 1064 unclassi ed line
8954.681 4.5 11713.22 818.5 wrong classi ed line
9471.136 3.5 12321.92 870.5 new line
9671.920 4.5 12519.72 693 unclassi ed line
[1] B. Gamper, Diploma thesis, Graz 2007, unpublished
[2] A. Ginibre-Emery, PhD thesis, Paris 1988
CP 193
215
New lines of atomic niobium in Fourier transform
spectra with enhanced sensitivity
Alev Er1, Ipek K. ¨ Ozt¨urk1, G¨on¨ul Ba¸sar1, Sophie Kr¨oger2, G¨unay Ba¸sar3,
Andrey Jarmola4, Maris Tamanis4, and Ruvin Ferber4
Istanbul University, Faculty of Science, Physics Department, 34134 Vezneciler, Istanbul,
Turkey
Technische Universit¨at Berlin, Institut fr Optik und Atomare Physik, Hardenbergstr.36,
10623 Berlin, Germany
Technical University of Istanbul, Faculty of Science and Letters, Physics Engineering
Department, 34469 Maslak, Istanbul, Turkey
University of Latvia, Faculty of Physics and Mathematics, Laser Centre, 19 Rainis
Blvd., Riga LV-1586, Latvia
This work is a continuation of our hyperfine structure studies of the atomic niobium. Recently,
the spectrum of Nb from a hollow cathode discharge was recorded in the wavelength
region from 330 nm to 800 nm with a high-resolution Bruker IFS 125HR Fourier transform
spectrometer in Riga with resolution of 0.02 cm−1 [1]. To increase the sensitivity of the
Fourier transform measurements, an interference filter was introduced in the beampass
to limit the spectral range of the light that came from the hollow cathode discharge and
entered to the Fourier transform spectrometer. We used different interference filters in
the range of 410 nm to 670 nm, each with spectral bandwidth of about 10 nm. By this
method a strong increase of the signal-to-noise ratio has been obtained. Even lines that
had not been seen at all in the previous measurements by Fourier transform spectroscopy
(without filter), now become clearly visible. The measured spectra include some previously
unknown Nb spectral lines not listed in the wavelength tables [2,3] as well as lines
without classification [2]. The hyperfine structure profiles of the spectral lines have been
analyzed with a least-squares-fit procedure assuming a Doppler profile. Experimental hyperfine
structure constants A of atomic niobium were determined. For unclassified lines,
several fits were performed assuming different values of angular momentum J for the fine
structure levels involved. The J values of the best fit together with the resulting hyperfine
structure constants A, provide relevant information for the classification of the transitions.
Riga team acknowledges support from LZP grant No. 04.1308. A.J. is grateful for support
from ESF grant.
[1.] A. Er eet al., paper in preparation
[2.] C. J. Humphreys and W.F. Meggers, National Bureau of Standards, Vol. 34, (1945)
[3.] Frederick, M. Phelps III, M.I.T. Wave-Length Table, Volume 2: Wavelength by
element, The MIT Press, Cambridge, Massachusetts, London, England (1991).
CP 194
216
Configuration interaction effects in the fine- and
hyperfine structure of the even configuration system
of tantalum atom
J. Dembczy´nski, M. Elantkowska, J. Ruczkowski
Chair of Quantum Engineering and Metrology, Faculty of Technical Physics, Poznan
University of Technology, Nieszawska 13B, 60-965 Poznan, Poland
E-mail: jerzy.dembczynski@put.poznan.pl
The experimental work of L.Windholz and co-workers, concerning observation of the tantalum
spectrum, yield many informations about new energy levels and hyperfine structure
splittings.
We contribute the results of the complex parametric studies of the fine- and hyperfine
structure of the mentioned element up to second-order of perturbation theory. The work
has been performed for the systems including 36 even configurations. The values of
the radial parameters describing the one- and many-body interactions effects on atomic
structure are given. We predicted values of energy levels and their A- and B- hyperfine
structure constants, also for experimentally levels not observed up to now.
This work was supported by Polish Ministry of Science and Higher Education under the
project N519 033 32/4065
CP 195
217
Extended analysis of the even con gurations of Ta II
Ewa Stachowska1, Jerzy Dembczy nski1 and Laurentius Windholz2
1Chair of Quantum Engineering and Metrology, Pozna n University of Technology,
Pozna n, Poland
2Institute of Experimental Physics, Graz University of Technology, Graz, Austria
The structure of Ta II is of particular interest in astrophysical studies, especially of chem-
ically peculiar stars, such as Lupi.
This work extends the analysis of the complex atomic structure of the tantalum ion, using
extensive ne and hyper ne structure calculations of the system of the following 25 even
con gurations :
5d4 + 5d3n0g (n0=5-6) + 5d36s + 5d36d + 5d26s2 + 5d26sn0g (n0=5-6) + 5d26sn00d (n00=6-10)
+ 5d26sn000s (n000=7-10) + 5d25f6p + 5d26p2 + 5d6s2n00d (n00=6-7) + 5d6s6p2 + 5d5f6s6p
+ 5d5f6s7p + 5d6s6d7s.
Previously only low lying levels of the (5d + 6s)4 con guration system up to 40000 cm􀀀1
were well known, identi cation supported by their hyper ne structure. Levels of higher
con gurations, from 70000 cm􀀀1 upwards are found, but their identi cation is still lacking
and further study is needed. Results will be presented at the conference.
This work was partially supported by PUT (project DS 63-029/08).
CP 196
218
Search for new electronic levels in singly ionized
europium Eu II
B. Furmann
Chair of Quantum Engineering and Metrology
Faculty of Technical Physics, Poznan University of Technology
boguslaw.furmann@put.poznan.pl
Experimental search for new electronic levels in rare earths, combined with determination
of the parameters, which allow a correct classification of those levels, such as J quantum
number, gJ factor or hyperfine structure constants A and B, has an significant influence
on both the improvement of precision of the theoretical description of interactions in
particular atoms (particularly in a semi-empirical method) and some applications in other
branches of physics, e.g. investigations of abundance of particular atoms or ions in stellar
atmospheres [1].
In the case of europium ion Eu II the electronic levels system is slightly different from the
typical pattern of other lanthanides. The known electronic levels of the odd configurations
4f76s and 4f75d have energies in the range 0-17500 cm−1. Above this value a large gap
is present and the next levels can be found at the energies above 50000 cm−1. On the
other side, theoretical predictions [2] yield an energy gap in the system of electronic levels,
but only covering the range 17500-26000 cm−1; at energy values between 26000 cm−1 and
50000 cm−1 several tens of electronic levels should occur. The tables of spectral lines of
Eu II [3] contain several tens of unclassified spectral lines.
In the present contribution results of search of new electronic levels, based on investigations
of the hyperfine structure of unclassified spectral lines with the method of laser
induced fluorescence in a hollow cathode discharge, are presented. The method of investigation
has been similar to the one applied earlier for praseodymium ion [4]. On the
basis of the measured hyperfine A constants and determined fluorescence channels wavelengths,
combined with gJ values presented in [3], it has been possible to assign the levels
investigated to the theoretically predicted ones, however, their energies have not been
determined so far. A plan of continuations of the investigations is presented.
The work has been supported by Poznan University of Technology under project No
63-029/2008
References
[1] C. Travaglio, D. Galli, R. Gallino, M. Busso, The Astrophys. Journal 521, 691-702,
(1999)
[2] J. Dembczynski, M. Elantkowska, J. Ruczkowski ”Private communication”
[3] H. N. Russel, W. Albertson, and D. N. Davis, Phys. Rev 60 , 641-656, (1941)
[4] B. Furmann, D. Stefanska, J. Dembczynski, E. Stachowska, Physica Scripta 72, 300-
308, (2005)
CP 197
219
Analysis of the odd configurations of tantalum atom
search for configurations containing f electrons
B. Arcimowicz, J. Dembczy´nski
Chair of Quantum Engineering and Metrology, Faculty of Technical Physics, Poznan
University of Technology, Nieszawska 13B, 60-965 Poznan, Poland
E-mail: bronislaw.arcimowicz@put.poznan.pl
Recently the structure of tantalum atom has been extensively investigated, in particular
by three groups: from Graz, Hamburg and Pozna´n. So far the energies of more than 260
electronic levels, belonging to odd configurations of tantalum atom, have been established
and their hyperfine structures have been determined. Attempts at classification of those
levels, based on the semi-empirical calculations, have been made. The wavefunctions
obtained in this procedure have further been used to calculate the A and B hyperfine
structure constants. However, only for less than twenty lowest-lying levels a satisfactory
agreement has been obtained. Results of the analysis indicated a strong configurations interaction.
Semi-empirical calculations performed in the multiconfiguration approximation
5d4n0p + 5d36sn0p + 5d26s2n0p (where n0=6-10) with conservation of the values of effective
quantum numbers neff have still omitted several levels with energies in the range 40000-
50000 cm−1. It suggested the existence of other configurations, which positions were,
however, inconsistent with predictions based on multiconfiguration Hartree-Fock calculations.
Taking into account 27 or 28 configurations, including additional configurations
of the type 5d36sn00f + 5d26s2n00f + 5d4n00f (where n00=5-7), although it has improved
the consistency of the fitted parameters gJ and the levels energies with the respective
experimental values, it nevertheless has not solved some differences. In the subsequent
stage of calculations an attempt of reduction of the configuration basis to merely 9 configurations
has been made, but simultaneously some hitherto not considered interactions
in the second order perturbation theory have been included. A better precision of these
calculations allowed to determine the positions of configurations 5d35f6s and 5d25f6s2.
The lowest-lying level of the former configuration containing the f electron is the recently
found level of the energy E = 47740.71 cm−1 with the value of hyperfine structure constant
A=−2500 MHz. For many levels the deciding test of classification have been the
hyperfine structure constants B, which varied strongly, since the values of the constants
A have been very close to each other. The results obtained are discussed in detail within
this work
References
[1] N. Jaritz, L. Windholz, U. Zaheer, M. Farooq, B. Arcimowicz, R. Engleman Jr, J. C.
Pickering, H. J¨ager and G. H. Guth¨ohrlein, Phys. Scr 74, 211-217 (2006)
CP 198
220
Program package for semi-empirical analysis of the
fine- and hyperfine structure of complex atoms
J. Ruczkowski, J. Dembczy´nski, M. Elantkowska
Chair of Quantum Engineering and Metrology, Faculty of Technical Physics, Poznan
University of Technology, Nieszawska 13B, 60-965 Poznan, Poland
E-mail: jerzy.dembczynski@put.poznan.pl
The experimental work combined with semi-empirical calculations is a very efficient tool
for the investigations of the fine- and hyperfine structure of the complex atoms.
We present a set of programs for the analysis of the fine- and hyperfine structure. The
input data for the calculations are : the fine structure energy levels, the gJ -factors and the
hyperfine structure (hfs) A and B constants of experimentally observed levels. In order
to avoid mistakes, all input data are set once in the initial input file and are transferred
between the programs automatically.
The programs are used for the analysis of electron systems containing any number of
configurations up to four open shells. In the energy matrix generated, all kinds of electrostatic,
magnetic and correlated electrostatic and magnetic interaction, up to second order
perturbation theory, were included.
As a result, we obtain predicted energy values for all the levels of the system considered,
their exact spectroscopic description, eigenvector amplitudes and also gJ -factors and hfs
A and B constants.
The program package contains supplementary programs useful for clear presentation of
results of calculations and their analysis.
This work was supported by Polish Ministry of Science and Higher Education under the
project N519 033 32/4065
CP 199
221
Procedure for precise determination of the hyperfine
structure constants A, B, C and D. Example of
lanthanum atom
M. Elantkowska, J. Ruczkowski, J. Dembczy´nski
Chair of Quantum Engineering and Metrology, Faculty of Technical Physics, Poznan
University of Technology, Nieszawska 13B, 60-965 Poznan, Poland
E-mail: jerzy.dembczynski@put.poznan.pl
High precision measurements of the hyperfine structure (hfs) splittings of electronic levels,
especially by rf-spectroscopic methods [1, 2, 3] make it possible to study even fairly complicated
aspects of the interaction between electron shells and the nucleus, which can result
in determination of the nuclear moments with high accuracy. We report the parametrization
method of the hyperfine structure which takes into account simultaneously one and
two-body effects appearing in the second order perturbation theory.
The analysis of the hfs of the even configurations of La atom was performed in the basis
of 3 configurations taking into account all possibles interactions predicted by many-body
fine structure theory. In order to include the J-off-diagonal effects in the hyperfine structure,
direct diagonalization of the matrix containing J-diagonal as well as J-off-diagonal
elements has to be performed (in the basis of (configuration, vSLJF) states). Usually,
the ”repulsion” effects of the neighbouring levels with the same quantum number F are
considered. It requires the precision up to 16 significant digits. The diagonal part of this
matrix consists of coefficients corresponding to particular components of the energy of a
hyperfine structure sublevel EF : center of gravity of hfs energy WJ and the experimental
hfs constants A, B, C and D. These parameters are treated as free in the fitting procedure
of the experimental and the calculated hfs energies (EF ). The differences between EF and
EF±1 values are equal to experimentally determined hyperfine structure intervals. Values
of J-off-diagonal matrix elements are fixed.
As a result, we obtain final values of the hyperfine structure constants, which can be used
again to determine the radial hfs parameters.
This work was supported by Polish Ministry of Science and Higher Education under the
project N519 033 32/4065
References
[1] Y. Ting, Phys.Rev. 108, 295, (1957)
[2] W.J. Childs, L.S. Goodman, Phys.Rev. A3, 25, (1971)
[3] W.J. Childs, U. Nielsen, Phys.Rev. A37, 6, (1988)
CP 200
222
Investigations of the Hyperfinestructure of
Praseodymium in the IR-Region with the help of
FTS
Bettina Gamper1 and Laurentius Windholz1
1 Institute of Experimental Physics, Graz University of Technology,
Petersgasse 16, 8010 Graz, Austria
The density of the spectral lines of praseodymium is very high. Therefore there are a
lot of unknown and not classified lines and levels. One kind of investigation one can do
is to analyze the fourier-transform-spectra (FTS). That is exactly what we did in the
IR-region of praseodymium. In this region there are a lot of lines which are not classified
and therefore not related to a spectral transition between two energetic levels. If you
look through the FTS you can immmediately see and then also analyze the characteristic
hyperfinestructure of several transitions.
With the help of FTS we could classify about 200 new spectral lines. That does not mean
that they are all already related to a spectral transition, some of them are just marked
as here is a line. The reason why we could not assigne each line to a transition is that
either the intensity of a line was to weak to see all of their components or that there was a
blend-situation between severeal ennergetic transitions. One very successful way to solve
such a problem is to make some investigations via laserinduced fluorescencespectroscopy.
That would be the next step in our work.
Another thing which we did was that we could correct some energies or hyperfineconstants
of already known levels or also give a more precise center of gravity of some lines. As
well we could relate a lot of already classified lines to a spectral transition between two
previously known energetic levels.
Of course it also was possible to find some new energylevels. That can be done via fitting
some very intens lines. For example we calculated the following two new levels:
level energy/ cm−1 J value A value/ MHz parity investigated line/ °A
20467.49 2.5 800 o 9293.848
22442.19 7.5 961 o 9319.011
A clear indication that those new energetic levels are correct is that they also explain
other lines in the spectra.
CP 201
223
Investigation of the hyper¯ne structure of Ta I-lines
P. GÃlowacki1 , L. Windholz2 and J. Dembczy¶nski1
1Chair of Quantum Engineering and Metrology, Pozna¶n University of Technology
Nieszawska 13B, 60-965 Pozna¶n, Poland
2Institute of Experimental Physics, Graz University of Technology Petersgasse 16,
A-8010 Graz, Austria
E-mail: przemyslaw.glowacki@doctorate.put.poznan.pl
Investigations of the hyper¯ne structure in tantalum began in the thirties of 20th century
[1,2]. Numerous research groups all over the world obtained many experimental results
concerning the tantalum spectrum [3,4,5]. The theoretical group under supervision of
Prof. Dembczy¶nski included all known experimental results in a semi-empirical analysis
of the electronic structure of tantalum atom. This calculations show that there are still
plenty of predicted energy levels that require experimental con¯rmation or discovery.
In our experimental investigations we used a hollow cathode lamp producing free Ta atoms
by sputtering, which were excited by a tunable dye laser operating with coumarine 102
(480-510nm). The laser-induced °uorescence was detected. Several spectral lines, which
appear in a Fourier transform spectra (FTS) and were unclassi¯ed, were excited. The
energy of some electronic levels and the values of their hyper¯ne constants A and B were
obtained.
Table I. Ta I lines investigated and classi¯ed by laser excitation.
Excitation
wavelength
Even level Odd level
[ºA, air]
4870.082
4900.354
4909.322¤
4909.395¤
4934.261
4939.771¤
5000.391
5000.981
Energy [cm¡1] J
new 54024.941 3.5
53598.985 3.5
55080.053 4.5
20646.702 3.5
23912.929 4.5
27412.440 1.5
25655.493 2.5
22761.279 3.5
Energy [cm¡1] J
33497.154 4.5
33197.724 3.5
34716.237 5.5
41010.121 2.5
44173.713 4.5
a 47650.666 1.5
45648.307 3.5
42751.800 3.5
¤ - new center of gravity, a - level predicted by calculation from FTS, con¯rmed by LIF
methods
This work was performed within the project of WTZ PL07/2007.
References
[1] E. McMillan, N.S. Grace, Phys. Rev. 44, 949-950 (1933)
[2] Gisolf and Zeeman, Nature 132, 566 (1933)
[3] G.H. GuthÄohrlein, L. Windholz, Z.Phys D 27, 343-347 (1993)
[4] B.Arcimowicz, A. Huss, S. Roth, N. Jaritz, D. Messnarz, G.H. GuthÄohrlein, H. JÄager,
L. Windholz, Eur. Phys J. D 13, 187-194 (2001)
[5] N. Jaritz, L. Windholz, U. Zaheer, M. Farooq, B. Arcimowicz, R. Engleman Jr, J.C.
Pickering, H. JÄager, G.H. GuthÄohrlein, Phys. Scr. 74, 211-217 (2006)
CP 202
224
Perturbed intensity distribution of hyperfine
components of Praseodymium-I lines
I. Siddiqui, B. Gamper, G.H. Guthöhrlein and L. Windholz
Institut für Experimentalphysik, Techn. Univ. Graz, A-8010 Graz, Petersgasse 16,
windholz@tugraz.at
Excitation of Praseodymium-I atoms with wavelength 578.051 nm led to observation of
laser-induced fluorescence signal at 618.3 nm with anomalous intensity distribution of the
hyperfine components. The recorded structure appeared to be a convolution of more than
one structures apparently depicting an excitation and fluorescence blend situation, which
may be observed when investigating Praseodymium atoms, due to the high level density.
But the same structure appeared also on all other fluorescence channels, thus we had to
conclude that more than one transition is always excited, and that either two lower or two
upper levels form a narrow spaced pair. These levels could disturb each other, explaining
also the quite unusual intensity distribution of the hyperfeine patterns. The first part of
the structure showed small components on both sides of the huge diagonal components,
indicating ΔJ = 0. From the spacing of the components, a transition between levels
with high angular momentum, 15/2 − 15/2, was suggested, while the strong decrease of
the intensity of the diagonal components indicated small J-values. A fit of the structure
with 15/2 − 15/2 gave A-factors which did not coincide with A-factors of already known
levels, thus we had to conclude that we have excited a transition where lower and upper
level were up to now unknown. Nevertheless, by an analysis of the wave numbers of the
observed fluorescence lines we were able to locate the upper level of the excited transition
at a wave number of 32486.80 cm−1, with J = 15/2 and even parity. Excitation with
wavelength 618.3 nm confirmed our assumptions concerning energy and J of this upper
level without doubt; its A-factor was 552.5 MHz. Thus we were able to find also the wave
numbers of the pair of lower levels excited with 578.051 nm. In further investigation we
found that another third level is located very close to this pair.
These levels are
15192.090 cm−1, J = 15/2, A = 730 MHz, odd parity
15191.906 cm−1, J = 13/2, A = 730 MHz, odd parity
15191.233 cm−1, J = 13/2, A = 666 MHz, odd parity
During our systematic investigations we found three other new upper levels, which could
be excited from this level triplet, all showing disturbed intensites of the hyperfine components.
CP 203
225
Investigation of the hyperfine structure of Pr I lines
in the region 5630 °A to 5830 °A
Shamim Khan, Syed Tanweer Iqbal, Imran Siddiqui and Laurentius Windholz
Institut f¨ur Experimentalphysik, Techn. Univ. Graz, A-8010 Graz, Petersgasse 16,
windholz@tugraz.at
We investigated the hyperfine structures of several spectral lines of Praseodymium by
using laser excitation in a hollow cathode discharge. Up to now seventeen unknown energy
levels with odd parity, nine levels with even parity and one ionic odd level were found.
The region investigated is in between 5630 °A and 5830 °A. The excitation source is a R-6G
ring-dye laser pumped by a solid state diode-pumped, frequency doubled Nd:Vanadate
(Nd:YVO4) Verdi V-18 laser system. The dye was pumped at 7.5 W power of pumping
source. We recorded characteristic hyperfine patterns, from which we determined both
J-values and magnetic dipole interaction constants A of the combining levels. Using these
constants and excitation and fluorescence wavelengths, we were able to find the energies
of the new levels. The excitation wavelengths were taken from FT Spectra [1].
Levels confirmed by a second laser excitation are given in the following table.
Excitation Wavelength Signal/Noise in FT Spectra Discovered Odd Levels
°A
J Energy/ cm−1
1 5739.179 6 7.5 25370.613
2 5656.938 7 6.5 26036.412
3 5634.304 22 5.5 26848.512
4 5828.609 4 2.5 28513.813
5 5808.605 17 8.5 28694.509
6 5720.270 4 6.5 30135.271
7 5721.189 4 6.5 30509.771
8 5647.923 2 3.5 30828.498
9 5635.388 3 5.5 31562.583
Discovered Even Levels
°A
J Energy/cm−1
10 5630.85 20 7.5 28474.777
11 5669.693 3 5.5 29363.344
12 5659.606 1 4.5 30485.255
13 5636.680 4 4.5 31962.250
Reference:
1. B.Gamper, Diploma Thesis, Technical University of Graz, 2007 (Unpublished)
CP 204
226
Correction of Pr I energy levels values due to Fourier
transform spectra and laser excitation
G. Krois, G.H. Guthöhrlein and L. Windholz
Institut für Experimentalphysik, Techn. Univ. Graz, A-8010 Graz, Petersgasse 16,
windholz@tugraz.at
The electronic ground state configuration of 59P r141 is [Xe]4f 36s2, with ground state level
4I9/2. Excitation of one or more electrons of the open f-shell or one of the s-electrons
forms a huge number of metastable and excited state levels. In our level data base on Pr
we use in moment approximately 1100 levels of odd and 750 levels of even parity, but this
list of levels is quite far from being complete.
Due to the high number of levels, the line density is also very high, in average 5 to 10 lines
per Å. In our line list (based on ref.[1]) we have now 20000 spectral lines. Thus, only with
the help of their hyperfine structure the transitions, explaining the lines, can be selected.
This classification is supported by a specially developed computer program (ref.[2]), which
is now extended to show immediately a part of a Fourier transform spectrum (FTS) [3],
and allows to compare easily calculated hyperfine patterns with structures appearing in
the FTS (of course for this the hyperfine constants of the combining levels must be known).
Accurate center of gravity (cog.) wavelengths, obtained fromour calibrated FTS, allows to
determine more accurate level energies (usually we use for this the vacuum wave number in
cm−1). Starting from the ground level (which has odd parity), a huge number of energies
of even upper levels could be corrected. The same is true for upper odd levels, taking the
lowest even level, 4432.24 cm−1, as basis.
Without accurate level energy and without correct excitation and emission wavelength
a certain transition can not be identified in the FTS and can not be excited in laser
spectroscopic studies. This information is given quite often insufficient, as we have recently
seen for example in ref. [4]. We repeat here the data for one level, published as new in
[4]: Excitation wavelengths 5885.76; 5829.5; 5800.19; 5707.90 Å, energy 28698.51 cm−1,
odd parity, fluorescence wavelengths 4465.23; 5101.76; 5144.97 Å, A = 767.4(3.3) MHz.
Identifying with the help of the given A-factor hyperfine structures which may be decays
of this level, we determined a level energy between 28698.073 cm−1 and 28698.103 cm−1,
depending on the treated line. Moreover, we performed laser excitation with cog. wavelength
5800.48 Å, and came to 28698.03 cm−1. These different results for the level wave
number show, that the energy differences between the even lower levels are not completely
correct. Assuming 28698.103 cm−1 as most reliable, we re-calculate the excitation wavelengths
given in [4] to be 5885.957, 5829.801, 5800.456, 5708.234 Å and the fluorescence
wavelengths to be 4466.053, 5102.419, 5145.418 Å in full agreement with position and
pattern of lines appearing in the FTS. Taking into account the wavelength differences up
to 0.5 Å and the high line density, it is nearly impossible to identify the lines mentioned
in [4]. In general, the energies in [4] are more reliable than the wavelengths, since the
conversion from vacuum wave number to air wavelength was done quite insufficient.
[1] A.Ginibre, Thesis, (Paris 1988); [2] L.Windholz, G.Guthöhrlein, Phys. Scr. T105, 55-
60 (2003); [3] B.Gamper, diploma thesis (T.U. Graz, 2007); [4] B.Furmann, A.Krzykowski,
D.Stefanska, J.Dembczynski, Phys. Scr. 74, 658 (2006)
CP 205
227
Normal spectral emissivity depending on atomic
composition for two nickel-based and two
ferrous-based alloys at 684.5 nm
C. Cagran1, H. Reschab1, R. Tanzer2, W. Sch¨utzenh¨ofer2, A. Graf2, G. Pottlacher1
1Institut f¨ur Experimentalphysik, TU Graz, Petersgasse 16, 8010 Graz, Austria
2B¨ohler Edelstahl GmbH & Co KG, Mariazellerstrasse 25, 8605 Kapfenberg, Austria
The Subsecond Thermophysics Workgroup at TUGraz mainly investigates thermophysical
properties, such as electrical resistivity, specific heat capacity and density of solid
and liquid metals and alloys as a function of temperature. A fast pulse-heating system
is used, which also allows the determination of normal spectral emissivity under pulse
heating conditions. For this purpose, a laser polarimeter, proposed in the 1980’s and later
developed by R. M. A. Azzam for the determination of optical constants without any
moving parts, was adapted for this μs-pulse heating experiment.
The change in polarization of a laser beam reflected off the surface of the wire-shaped sample
material during a pulse heating experiment enables the measurement of temperaturedependent
normal spectral emissivity at melting and in the liquid state at the used laser
wavelength. Knowledge of emissivity and its behaviour throughout the liquid phase can
improve the understanding of interacting effects between light and the molten alloy. The
industrial cooperation partner B¨ohler Edelstahl GmbH & Co KG is interested in emissivity
data for numerical simulations of plastic deformation and remelting processes as well
as for process optimisation.
As observed from numerous experiments with various sample materials the liquid state
behaviour of normal spectral emissivity at 684.5nm can be classified into three groups,
namely increasing, decreasing and constant emissivity with increasing temperature. Based
on this finding, it can be shown that the behaviour of normal spectral emissivity in
conjunction with the radiometric temperature measurement is needed to achieve reliable
thermophysical properties of liquid metals.
Within this presentation normal spectral emissivity data at 684.5nm for two nickel-based
alloys (Nimonic 80A and Inconel 718), as well as the austenitic steel X2CrNiMo18-14-3
and another ferrous-based alloy at melting and in the liquid state are presented.
Research supported by B¨ohler Edelstahl GmbH & Co KG and the
”
Forschungsf¨orderungsgesellschaft
mbH, Sensengasse 1, 1090 Wien, Austria“, project 812972.
CP 206
228
Identification of atomic structure in measurement
data, depending on the used set of units
T. H¨upf1, C. Cagran1, G. Pottlacher1, G. Loh¨ofer2
1Institut f¨ur Experimentalphysik, Technische Universit¨at Graz, Austria
2Institut f¨ur Materialphysik im Weltraum, DLR K¨oln, Germany
Hardly any scientific topic can be treated without a closer specification of quantities. In
natural sciences this is commonly done by choosing an appropriate, standardized system of
units, generally the SI, or sometimes a ratio of selected quantities. With such an approach
numerical data are compared to a well-defined unit and reported as a fraction or multiple
thereof.
The presented work wants to demonstrate how the choice of different units can lead to a
totally different presentation of results, which might help to reveal yet unseen coherences.
This idea is reviewed on the example of measurements performed with a fast pulse heating
method.
Using this pulse heating technique wire shaped samples are resistively volume heated
as part of a fast capacitor discharge circuit. Time resolved electrical measurements with
sub-μs resolution include the current through and the voltage drop across the specimen.
Surface radiance from the samples is detected by pyrometers and the thermal expansion
of the sample can be monitored by means of a custom-made fast CCD-camera. Based
on these measured quantities, temperature-dependent thermophysical properties such as
enthalpy, isobaric heat capacity, electrical resistivity and thermal expansion can be deduced.
During the compilation of specific enthalpy results for numerous pure elements we observed
an organisation according to the periodic system of the elements. By using molar
instead of specific units the same results become rearranged and show the established law
of Dulong-Petit.
The project: Electrical Resistivity Measurement of High Temperature Metallic Melts is
sponsored by the FFG-ASAP programme.
CP 207
229
Electronic Wavefunction Microscopy using
slow-photoelectron Imaging
M. M. Harb[1], A. Ollagnier[1], S. Cohen[2], F. L´epine[1], F. Robicheaux[3], M.
Vrakking[4] and C. Bordas[1]
[1]Universit´e Lyon 1; CNRS; LASIM, UMR 5579, 43 bvd. du 11 novembre 1918,
F-69622 Villeurbanne, France.
[2]Atomic and Molecular Physics Laboratory, Physics Department, University of
Ioannina, 45110 Ioannina, Greece.
[3]Department of Physics, 206 Allison Lab, Auburn University, AL 36849-5311, USA.
[4]FOM-Institute AMOLF, Kruislaan 407, 1098 SJ Amsterdam, The Netherlands.
Photoelectron imaging spectroscopy has recently emerged as a powerful tool capable of
providing detailed information on the microscopic properties of matter. In a standard
velocity map imaging (VMI) experiment eV kinetic energy electrons or ions are projected
towards a 2D position sensitive detector. Therefore the obtained image corresponds to the
classical projection of a Newton sphere that, in principle, allows a direct reconstruction
of the initial 3D velocity distribution of the particles. Improvements on the standard
VMI set-up, allowing the study of meV electrons, led to the recording of 2D patterns
which are drastically modified with respect to those obtained with high kinetic energy
electrons. The most striking effect is the observation of radial signal modulations due
to quantum interferences [1]. Moreover, ionic core gives rise to a re-scattering ionization
channel [2]. Simulations based on wavepacket propagation have been performed and
we have shown that when ionization of Hydrogenic atoms occurs via a Stark resonance
above the saddle point energy, the measured image represents a direct projection of the
bound component of the electronic wavefunction magnified to macroscopic dimensions
by a factor 106. Hence it is fully justified to consider the meV-VMI apparatus as a
photoionization microscope, corresponding to the smallest Youngs slit experimental setup
ever implemented [3, 4]. For a non-hydrogenic atom, on the other hand, the presence
of the electronic core leads to mixing of the parabolic electronic states which modifies the
wavefunction. As a consequence, a smooth evolution of the interferogram patterns with
energy is expected. Experimental results on Xe and Li will be presented and discussed.
[1] C. Nicole, H.L. Offerhaus, F. L´epine, C. Bordas, and M. Vrakking, Phys. Rev. Letters
88 (2002) 133001. [2] C. Nicole, I. Sluimer, F. Rosca-Pruna, M.Warntjes, M.J.J. Vrakking,
C. Bordas, F. Texier and F. Robicheaux, Phys. Rev. Lett. 85 (2000) 4024. [3] C. Bordas,
F. L´epine, C. Nicole and M. Vrakking, Phys. Rev. A68 (2003) 012709. [4] F. L´epine,
S. Zamith, A. de Snaijer,Ch. Bordas and M.J.J. Vrakking, Phys. Rev. Lett. 93 (2004)
233003.
CP 208
230
On a self-sustained oscillating mode for operation of
a glow discharge
E. Dimova, D. Zhechev and V. Ste ekova
Institute of Solid State Physics, Bulgarian Academy of Sciences
72 Tzarigradsko Chaussee Blvd., BG-1784 SOFIA, BULGARIA
e-mail: spectron@issp.bas.bg
Numerous glow discharge (GD) applications are based on its stable mode for operation.
From another point of view, the gaseous plasma in a GD is known as a typical nonlin-
ear dynamical "open system" with a large number of degrees of freedom. Within these
frames a GD modi cation, i.e. hollow cathode discharge (HCD) should possess one more
additional degree of freedom due to the speci c Penning ionization of sputtered atoms.
A self-sustained oscillating mode for operation of a hollow cathode discharge (HCD) is
analyzed based on an equivalent glow discharge RCL scheme. The oscillation takes place
under i-V operating point of positive di erential resistance and its frequency ( kHz)
depends on the discharge current value. The self-sustained instabilities correlate with the
plasma space structure in the cathode cavity.
If the value is a small deviation of the continuous discharge current i0 , i.e. i = i0 + ,
the equation
a ( @ / @t)2 + b ( @ / @t) + d = 0
is found to describe a non damping oscillating function (t) under some combinations (
a, b, d ) of reasonable data values characterizing glow discharge plasma in general.
CP 209
231
Atomic beam measurements of the Cs 7d 2D3=2
hyper ne parameters with two-photon uorescence
spectroscopy
A. Kortyna and V. Fiore
Department of Physics, Lafayette College
Easton, PA 18042, U.S.A.
The hyper ne intervals of the 7d 2D3=2 manifold are measured by interrogating an e usive
beam of atomic cesium with resonant two-photon laser-induced- uorescence spectroscopy.
This work adapts the laser system previously used to measure hyper ne splittings in
a vapor cell [1]. Two external-cavity diode lasers drive the two-step excitation of the
7d 2D3=2 state. One laser is center locked to a 6s 2S1=2(F00) ! 6p 2P3=2(F0) transition using
magnetic dithering and a servo-feedback circuit. The second laser is scanned over the
6p 2P3=2(F0) ! 7d 2D3=2(F) transitions.
The scanned laser's frequency scale is calibrated with an electro-optic modulator. Phase
modulation introduces sidebands to the laser frequency at precise intervals. As the laser
frequency is scanned across an atomic feature, the sidebands cause the feature to be
repeated at intervals equal to the modulation frequency, providing calibration frequency
markers. High accuracy is achieved by directly referencing the modulation frequency
to the 87Rb 5s 2S1=2(F = 1) $ 5s 2S1=2(F = 2) ground-state hyper ne transition using
an atomic frequency standard. To enhance resolution, nonlinear tting of Voigt pro les
is used to locate the centroid of each uorescence peak. The observed linewidths are
8:2 0:1 MHz, and the hyper ne intervals are determined with overall uncertainties of
200 kHz. The uncertainty includes contributions from the tting procedure, jitter in the
frequency scale calibration, and statistical uncertainty.
The hyper ne intervals are used to generate the magnetic dipole coupling constant A =
7:36 0:03MHz and the electric quadrupole coupling constant, B = 􀀀0:1 0:2 MHz. This
result is the rst time a constraint has been place on the B coupling constant. The A
coupling constant is in good agreement with a previous measurement [2] but with an order
of magnitude improvement in resolution. This result does not agree with a relativistic-
all-order calculation [3], but this disagreement is anticipated because of the di culty of
modeling electron correlation e ects. Our resolution is su cient to provide a benchmark
value for testing future improvements in high-precision theory. This work is generously
supported by Lafayette College and by the U.S. National Science Foundation through
Grant Numbers PHY-0244684, PHY-0653107, and ECCS-0722610.
References
[1] A. Kortyna, N. A. Masluk, and T. Bragdon, Phys. Rev. A, 74, 022503 (2006).
[2] G. Belin, L. Homgren, and S. Svanberg, Physica Scripta 14, 39 (1976).
[3] M. Auzinsh, K. Bluss, R. Ferber, F. Gahbauer, A. Jarmola, M. S. Safronova, U. I.
Safronova, and M. Tamanis, Phys. Rev. A 75, 022502 (2007).
CP 210
232
ELECTRON SCATTERING BY CADMIUM
ATOMS
O.B.Shpenik, E.E.Kontros, I.V.Chernyshova
Institute of Electron Physics, National Academy of Sciences of Ukraine
21 Universitetska str., Uzhgorod 88017, Ukraine
E-mail: an@zvl.iep.uzhgorod
We have performed an investigation of elastic and inelastic scattering of monoenergetic
electrons by cadmium atoms. The specific feature of the experiment is that, using a
hypocycloidal electron spectrometer, the total electron scattering cross-section, electron
energy loss spectra as well as constant residual energy spectra (threshold excitation spectra)
were measured at the same experimental conditions as well as the ionization crosssection
and excitation function for the lower atomic levels near the threshold.
The experiments were performed using a vapour-filled cell: an electron beam was formed
by a hypocycloidal electron monochromator [1], passed through the vapour-filled cell,
then through a hypocycloidal electron analyser and was detected by a deep Faraday cup.
Inelastically scattered electrons were registered by a separate detector and measured by
a digital picoamperemeter. Cadmium vapour was supplied to the cell from a separate
reservoir, its temperature being kept by 20 − 30 0C below the cell temperature. To
provide spectrometer operation, the axial magnetic field of 150 Oe strength was used
produced by Helmholtz rings. The detector of positive ions was located directly in the
cell, performed in a shape of a flat electrode, protected by a metallic grid and positioned
at a distance of 5 mm from the electron beam.
The threshold excitation spectra of Cd atom, measured at different values of the residual
electron energy from 0 to 1 eV , have shown a metastable 5 3P− level, then a resonance
5 1P1− level and the 6 3,1S− level to be the most effectively excited by electrons.
Taking into account the fact that the hypocycloidal analyzer enables all the inelastically
scattered electrons to be detected within 0.5−1.5 eV near the level excitation threshold,
we have measured the excitation functions for the lower 5 3P0,1,2−, 5 1P1−, as well as
6 3S1− and 6 1S1− levels. The form of the excitation function of the 5 3P0,1,2− and
5 1P1− levels is very close to the optical excitation functions of (5 1S0 − 5 3P1) and
(5 1S0 − 5 1P1) spectral lines, measured earlier [2].
The work was carried out in part in the framework of the agreement No. F014/309−2007
of DFFD of the Ministry of Education and Science of Ukraine.
References
[1] N.I.Romanyuk, O.B.Shpenik, I.A.Mandy, F.F.Papp, I.V.Chernyshova, Tech. Phys.
63, 138-147 (1993).
[2] N.M.Erdevdy, O.B.Shpenik, V.S.Vukstich, Opt.Spectr. 97, 559-565 (2004).
CP 211
233
Probing surface vibrations of amorphous solids by helium atom scattering
W. Steurer1, B. Holst1,*, J. R. Manson2, and W. E. Ernst1
1 Institute of Experimental Physics, Graz University of Technology, Austria
2 Department of Physics, Clemson University, South Carolina, USA
contact: wolfram.steurer@tugraz.at
While helium atom scattering has been a well established method for the investigation of
ordered surface structures, the technique has only recently shown its great potential for the
non destructive probing of the vibrational state density at amorphous interfaces [1,2]. No
diffraction can be observed from such interfaces but the energy transfer from the beam to the
surface and vice versa reveals valuable information about vibrational frequencies in a way
that is purely surface sensitive with no penetration into the bulk. In the experiment, a nearly
monochromatic beam of neutral He atoms of about 20 meV kinetic energy impinges on the
sample surface. Some helium atoms will exchange kinetic energy and momentum with the
surface via creation or annihilation of surface phonons while others scatter elastically and do
not change their kinetic energy. Upon arriving at the detector the kinetic energy of the atoms
is obtained by measuring their time-of-flight. The observed spectrum of energies is related to
the differential reflection coefficient and, as shown in our recent publication [1], a surface
phonon spectral density can be obtained. Procedures to determine the vibrational state density
at an amorphous silica surface and compare it with theoretical models, will be described in
this contribution.
[1] W. Steurer et al., Phys. Rev. Lett. 99, 035503 (2007).
[2] W. Steurer et a.., Phys. Rev. Lett. 100, 135504 (2008)
* present address: Department of Physics and Technology, University of Bergen, Norway
CP 212
234
Towards Direct Frequency Comb Spectroscopy using
Quantum Logic
Birgit Brandstatter, Borge Hemmerling, Lukas An der Lan, Piet O. Schmidt
Institut fur Experimentalphysik, Universitat Innsbruck, Technikerstrasse 25, A-6020
Innsbruck, Austria
A possible change of the ne-structure constant over cosmological time scales derived from
quasar absorption lines is currently strongly debated. One of the di culties turns out to
be the lack of precise laboratory data on transition lines of elements with a complex level
structure such as Ti+ and Fe+ [1].
We challenge this problem by developing a versatile experimental setup in which spectroscopy
ions are sympathetically cooled by magnesium ions in a linear Paul trap. Using
quantum logic techniques, initial state preparation and state detection of the spectroscopy
ion can be very e cient. Owing to the complex level structure of these spectroscopy ions,
repumping from unwanted states is required. We plan to implement this by applying an
appropriately tailored optical frequency comb.
We will present the latest status of our experimental setup and simulation results on the
expected uorescence signal from a Ca+ test candidate. We furthermore present schemes
based on quantum logic techniques to interrogate single ions in order to further improve
the accuracy of the spectroscopic data.
[1] J. C. Berengut, V. A. Dzuba, V. V. Flambaum, M. V. Marchenko and J. K. Webb,
arXiv:physics/0408017 (2006)
CP 213
235
Towards Cryogenic Surface Ion Traps
Michael Niedermayr1, Muir Kumph1, Piet Schmidt1, Rainer Blatt1;2
1Institut für Experimentalphysik, Universität Innsbruck, Technikerstrasse 25, 6020
Innsbruck, Austria
2Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der
Wissenschaften, Otto- Hittmair-Platz 1, 6020 Innsbruck
One promising approach for scalable quantum information processing (QIP) architectures
is based on miniaturized surface ion traps [1]. These traps with dimensions in the
sub-100 m range can be fabricated by photolithography techniques [2]. Generally, experimental
results indicate that the heating rate of the ions increases with decreasing trap
dimensions. The mechanism of this heating is not yet fully understood. However, the
heating rate can be reduced by several orders of magnitude when the trap electrodes are
cooled from room temperature to 4K [3, 4]. Within a new experiment which is presently
set up we intend to investigate surface traps at low temperatures in a cryogenic system.
These traps will be applied for quantum simulations, for fundamental investigations of
large-scale entanglement and for precision measurements enhanced by quantum metrology
techniques employing entangled particles.
[1]D. Kielpinski et al., Nature 417, 709 (2002)
[2]J. Chiaverini et al., Quantum Inf. Comput. 5, 419 (2005)
[3]J. Labaziewicz et al., Phys. Rev. Lett. 100, 013001 (2008)
[4]L. Deslauriers et al., Phys. Rev. Lett. 97, 103007 (2006)
CP 214
236
CROSS SECTIONS FOR ELASTIC ELECTRON
COLLISIONS WITH SMALL ALCOHOLS
I. Iga?, I. P. Sanches?, R. T. Sugoharay , M. G. P. Homem? and M. T. Lee?
Departamento de Qu mica, UFSCar, 13565-905 S~ao Carlos, SP, Brazil
yDepartamento de F sica, UFSCar, 13565-905 S~ao Carlos, SP, Brazil
E-mail: diig@ufscar.br
Recently, there is a clear interest on studies of electron scattering by molecules due to their
key role to physical and chemical transformations in elds of diverse nature, such as indus-
trial plasmas, radiation damage in biomaterials, etc. Despite these facts, for most targets
of interest, cross sections values are often not easily available. For instance, electron colli-
sions cross sections with oxygen containing-organic molecules are very scarce. Therefore,
in this contribution we will present electron scattering cross sections for methanol and
ethanol.
Concerning these simple alcohols, their discovery in interstellar space and in the atmo-
spheres of planets in the solar system has motivated recent studies of electron interaction
with such species. Also the amount of ethanol vapors in our atmosphere is certainly ex-
pected to increase in the near future since it is a renewable energy source that is being
increasingly used as an important bio-fuel to replace at least partially the usages of fossil
fuels. Nevertheless, information available on the interaction of intermediate energy elec-
trons and alcohols is still quite limited and mainly directed to the ionization processes
[1].
In this work we have carried out studies of elastic scattering of electrons in the inter-
mediate energy range, from ionization threshold to 1 keV. In our experiments [2], an
electron beam interacts with a gaseous beam formed by alcohol vapors and the intensities
of elastically scattered electrons are measured as a function of scattering angle in the (6
- 130 ) angular range. The relative ow technique [3] is used to convert the experimental
electron intensities to absolute di erential cross sections. Results of measured cross sec-
tions and their comparison with the calculated data using the independent atom model
at the static-exchange-polarization level of approximation will be presented during the
Conference.
We acknowledge support by the Brazilian agencies: CNPq and FAPESP.
References
[1] R. Rejoub, C. D. Morton, B. G. Lindsay, and R. F. Stebbings, J. Chem. Phys. 118,
1756-1760 (2003) 38 3477 (2005) and references therein..
[2] I. Iga, I. P. Sanches, E. de Almeida, R. T. Sugohara, L. Rosani, and M. T. Lee, J.
Electron Spectr. Relat. Phenom 155 7 (2007).
[3] S. K. Srivastava, A. Chutjian, and S. Trajmar, J. Chem. Phys. 63 2659 (1975).
CP 215
237
Contents
Evening Lecture
EL 1 R.F. Curl jr. (Nobel Price in chemistry 1996)
A brief History of Elemental Carbon
Plenary Lectures
PL 1 S. Haroche
Non-demolition photon counting and field quantum state reconstruction in a cavity: a new way to look
at light
PL 2 M. Quack
Theory and Spectroscopy of Parity Violation in Chiral Molecules
PL 3 J. Kluge
Precision Experiments with Heavy Ions
PL 4 J. Schmiedmayer
Atom Chips: Integrated circuits for matter waves
PL 5 F. Riehle
Optical Atomic clocks at the Frontiers of metrology
PL 6 A.Weis, P. Moroshkin, V. Lebedev, A. Hofer
Alkali Atoms, Dimers, Exciplexes and Clusters in 4He Crystals
PL 7 M. Scully
Generation of short wavelength radiation via Coherent hyper Raman Superradiance
PL 8 G.M. Tino
Cold Atom Interferometry for Gravitational Experiments
PL 9 Ch. Blondel
Photodetachment microscopy in a magnetic field
PL 10 P. Corkum
Laser induced-Tunneling, Electron Diffraction and Molecular Orbital Imaging
PL 11 A. Scrinzi
Few-electron dynamics in the interaction with strong fields
Invited Progress Reports
PR 1 R. Wester
Molecular Reaction Dynamics at Low Energies
PR 2 C. Champenois, G. Hagel, M. Houssin, C. Zumsteg, F. Vedel, M. Knoop
1, 2, 3 Photons for Trapped Ion Spectroscopy
PR 3 M. Richter, A.A. Sorokin
Non-linear Photoionization in the Soft X-ray Regime
PR 4 U. Becker
Multi-photon ionization and excitation oft the rare gases by Free Electron Laser radiation
PR 5 F. Lang, K. Winkler, C. Strauss, R. Grimm, J. Hecker-Denschlag
Ultracold deeply-bound Rb2 molecules
PR 6 P. Barker
Manipulating cold molecular gases with intense optical fields
238
PR 7 J.R. Crespo Lopez-Urrutia, S. W. Epp, and J. Ullrich
Resonant laser spectroscopy in the soft x-ray region
PR 8 V.L. Sukhorukov
Resonances in Rare Gas Atoms: Many-Electron Theory and Experiment
PR 9 R. Kienberger
Attosecond spectroscopy in atoms and solids
PR 10 J. Mauritsson
Above, Around, and Below Threshold Ionization using Attosecond Pulses
Contributed Papers
CP 1 F. Ferlaino, S. Knoop, M. Mark, M. Berninger, H. Schöbel, H.C. Nägerl, R. Grimm
Few-body physics with ultracold Cs atoms and molecules
CP 2 L. Pruvost, H. Jelassi, B. Viaris de Lesegno
Weakly bound molecules: Analysis by the Lu-Fano method coupled to the LeRoy-Bernstein model.
CP 3 M. Aymar, J. Deiglmayr, O. Dulieu
Calculations of static polarizabilities of alkali dimers and alkali hydrides. Prospects for alignment of
ultracold molecules
CP 4 L. van Buuren, C. Sommer, M. Motsch, M. Schenk, W.H. Pinkse, G. Rempe
Electrostatically extracted cold molecules from a cryogenic buffer gas
CP 5 H.-D. Kronfeldt, H. Schmidt, B. Sumpf, M. Maiwald, G. Erbert, G. Tränkle
In-situ non-invasive quality control of packaged meat using a micro-system external cavity diode
laser at 671 nm for Raman spectroscopy
CP 6 D. Pinegar, C. Diehl, R. van Dyck, K. Blaum
3H/3He mass ratio experiment MPIK/UW-PTMS in the context of ν-mass measurements
CP 7 S. Nic Chormaic , D. Gleeson, V. Minogin
Optical microtraps for cold atoms based on near-field diffraction
CP 8 Th. Becker, Th. Germann, P. Thoumany, G. Stania, L. Urbonas, T. Hänsch
Optical Spectroscopy of Rubidium Rydberg Atoms with a 297nm Frequency Doubled Dye Laser
CP 9 K. V. Rodriguez, V. Y. Gonzalez, L. U. Ancarani, D. M. Mtinik, G. Gasaneo
Helium 1,3S excited states obtained with an angular correlated configuration interaction method
CP 10 G. Gaigalas, E. Gaidamauskas, Z. Rudzikas
Atomic structure calculations of Cm+4 and Am+3 ions
CP 11 G. Gaigalas, E. Gaidamauskas, J. Bieron, S. Frizsche, P. Jönsson
MCHF calculations of the electric dipole moment of radium induced by the nuclear Schiff moment
CP 12 Sølve Selstø, J. Bengtsson, E. Lindroth
On the solution of the time dependent Dirac equation for hydrogen-like system
CP 13 M. Safronova, R. Pal, D. Jiang, U. Safronova
Calculation of parity-nonconserving amplitude in Ra+
CP 14 M. Safronova, M.G. Kozlov, W.R. Johnson
Development of the CI + all-order method for atomic calculations
CP 15 K. V. Rodriguez, V. Y. Gonzalez, L. U. Ancarani, D. M. Mtinik, G. Gasaneo
Ground state wavefunctions for two-electron systems with finite nuclear mass
CP 16 O.Y. Khetselius
Laser separation and detecting the isotopes and nuclear reaction products and relativistic calculating
the hyperfine structure parameters in the heavy-elements
CP 17 A.V. Glushkov, O.Y.Khetselius, A.A. Svinarenko
QED approach to the photon-plasmon transitions and diagnostics of the space plasma turbulence
239
CP 18 A.V. Glushkov
QED theory of laser-atom and laser-nucleus interaction
CP 19 Kh.Yu. Rakhimov
Quantum dynamics of planar hydrogen atom in a billiard with moving boundaries
CP 20 V.L. Sukhorukov, B.M. Lagutin, I.D. Petrov, A. Ehresmann, L. Werner, s. Klumpp, K.H. Schartner,
H. Schmoranzer
Interchannel interaction in orientation and alignment of Kr 4p4mp states in the excitation region of
3d9np resonances
CP 21 O. Rancova, P. Bogdanovich, R. Karpuskiene
Application of new quasirelativistic approach for treatment of oxygen-like Iron and Nickel
CP 22 Y.S. Kozhedub, D.A. Glazov, I.I. Tupitsyn, V.M. Shabaev, G. Plunien
Relativistic recoil and higher-order electron correlation corrections to the transition energies in Li-like
ions
CP 23 R. Jursenas
Coupled tensorial forms of atomic two particle operator
CP 24 V.K. Gudym, E.V. Andreeva
The binominal potential of electron-proton interaction alternative to the Coulomb law
CP 25 J. Bengtsson, E. Lindroth, S. Selstø
The dynamics of meta-stable states described with a complex scaled Hamiltonian
CP 26 L.U. Ancarani, G. Gasaneo
A simple parameter-free wavefunction for the ground state of three-body systems
CP 27 L.U. Ancarani, G. Gasaneo, F.D. Colavecchia, C. Dal Capello
(e, 3e) and (γ, 2e) processes on helium: interplay of initial and final states
CP 28 M.A. Bolorizadeh, R. Fathi, E. Gahnbari-Adivi, F. Shojaei
A three body approach to calculate the differential cross sections for the excitation of H and He atoms
by proton impact
CP 29 F. Umarov, A. Dzhurakhalov
The peculiarities of elastic and inelastic engery losses at low-energy ion-surface interactions
CP 30 R. Lomsadze, M. Gochitashvili, B. Lomsadze, N. Tsiskarishvili, D. Kuparashvili
Study of Mechanism in Alkali Metal Ion Inert Gas Atom Interaction
CP 31 I.I. Shafranyosh, R.O. Fedorko, V.I. Marushka, T.A. Snegurskaya, V.V. Perehanets, V.V. Stetsovych
Studies of superelastic electron scattering by the metastable Thallium atoms
CP 32 O.B. Shpenik, A.N. Zavilopulo
Ionization and Dissociative Ionization of Adenine Molecules by Electron Impact near Threshold
CP 33 L. E. Machado, I. Iga, L. M. Brescansin, M.-T. Lee
Absorption effects in intermediate-energy electron scattering by difluoroethylene
CP 34 S. Houamer, Y. Popov, C. Champion, C. Dal Capello
Charge transfer in collision of protons with water molecule and atomic helium at high energy
CP 35 S.Y.Kurskov, A.S. Kashuba
Ar(3p5 4p) states excitation in low-energy Ar-Ar collisions
CP 36 S. Gedeon, V. Lazur
Low-energy electron scattering from calcium
CP 37 J.Loreau, M. Desouter-Lecomte, F. Rosmej, N. Vaeck
Ab inition calculation of H + He+ electron transfer cross sections
CP 38 G. Purohit, U. Hitawala, K.K. Sud
TDCS for inner-shell (e, 2e) processes on alkali and alkali earth atoms Na, K, Be, Mg and Ca
CP 39 P. Syty
The relativistic J-matrix method in scattering of electrons from model potentials and small atoms
CP 40 V.S. Melezhik, P. Saeidian, P. Schmelcher
Multichannel atomic scattering and confinement-induced resonances in waveguides
240
CP 41 E. Ovcharenko, A. Gomonai, Yu. Hutych
Excitation of forbidden 4d95s2 2D5/2 - 4d105s 2P3/2 transition in In2+ ion at electron-In+ ion collisions
CP 42 A.O. Lindahl, P. Andersson, C. Diehl, O. Forstner, K. Wendt, D.J. Pegg, D. Harnstorp
The electron affinity of Tungsten
CP 43 M. Czarnota, D. Banás M. Berset, D. Chmielewska, J-Cl. Dousse, J. Hoszowaska, Y-P Maillard,
O. Mauron, M. Pajek, M. Polasik, P.A. Raboud, J. Rzadkiewicz, K. Stabkowska, Z. Sujkowski
High resolution measurements of molybdenum L-shell satellites and hypersatellites excited by oxygen
and neon ions
CP 44 L. Bandurina, V. Gedeon
Electron-impact scattering on boron
CP 45 E. Baszanowska, R. Drozdowski, P.Kaminski, G. von Oppen
Observation of He-He collisions using the anticrossing method
CP 46 V. A. Kartoshkin, S.P. Dmitriev, N.A. Dovator
Spin-exchange cross sections at the interaction between ground state rubidium and metastable helium
atoms
CP 47 V. A. Kartoshkin
Spin exchange and redistribution of the spin-polarization at the interaction between ground state
alkali atoms and nitrogen atoms in gas discharge
CP 48 L. Klosowski, M Piwinski, D. Dziczek, K. Pleskacz, S. Chwirot
Large angle e-He scattering - coincidence experiment with magnetic angle changer
CP 49 M.T. Bouazza, C. Benseddik, M. Bouledroua
Diffusion coefficient and viriel coefficient of Krypton Atoms in a Argon Gas at Low and Moderate
Temperature
CP 50 M.T. Bouazza, M. Bouledroua
A theoretical report on ultracold collisions of two monatomic Cesium
CP 51 V.M.Entin, I.I.Beterov, I.I. Ryabtsev, D.B. Tretyakov
Tomography of laser cooled atoms in MOT using Rydberg state excitation
CP 52 M. Mestre, F. Diry, B. Viaris de Lesegno, L. Pruvost
Spatial light modulators for cold atom manipulation
CP 53 O. Gorceix, Q. Beaufils, R. Chicireanu, T. Zanon, A. Crubellier, B. Laburthe-Tolra, E. Maréchal,
L. Vernac, J-C. Keller
All-optical Bose-Einstein condensation of Chromium atoms and rf spectroscopy of cold Cr2 molecules
CP 54 M. Seliger, U. Hohenester, G. Pfanner
Entangled photons from excitonic decay in artificial atoms
CP 55 J. Grond, U. Hohenester, J. Schmiedmayer
Optimizing number sqeezing when splitting a mesoscopic condensate
CP 56 I.E. Mazets, T. Schumm, J. Schmiedmayr
Breakdown of integrability in a quasi-one-dimensional ultracold bosonic gas
CP 57 J-F. Clément, J-P. Brantut, M. Robert de St. Vincent, G. Varoquaux, R.A. Nyman, A. Aspect,
T. Bourdel, P. Bouyer
Light-shift tomography in an optical-dipole trap
CP 58 H. Knöckel, S. Liu, I. Sherstov, C. Lisdat, E. Tiemann
Matter wave interferometry with K2 molecules
CP 59 E. Maréchal, B. Laburthe-Tolra, L.Vernac, J.-C. Keller, O. Gorceix
A magnetic lens for cold atoms tuned by a rf field
CP 60 T. Pfau, Th. Lahaye, J. Metz, B. Fröhlich, T. Koch, A. Greismaier
Stability and d -wave collapse of a dipolar BEC
CP 61 K. Chebakov, N. Kolachevsky, A. Akimov, I. Tolstikhina, P. Rodionov, S. Kanorsky, V. Sorokin
Blue cooling transitions of thulium atom
241
CP 62 J.Sczepkowski, R. Abdoul, R. Gartman, W. Gawlik , M. Witkowski, J. Zachorowski, M. Zawada
Free-fall expansion of finite-temperature Bose-Einstein condensed gas in the non Thomas-Fermi
regime
CP 63 N. Kolachevsky, E. Tereschenko, M. Egorov, A. Sokolov, A. Akimov, V. Sorokin
Resonance Interaction between Cold Rb Atoms and a Frequency Comb
CP 64 M. Witkowski, R. Gartman, W. Gawlik, J. Szczepkowski, M. Zawada
Optical tailoring of spatial distribution of the BEC and non-degenerate cold atoms. Non-periodic
optical lattice
CP 65 F. Tantussi, N. Porfido, F. Prescimone, V. Mangasuli, M. Allegrini, E. Arimondo, F. Fuso
Laser techniques for atom-scale technologies
CP 66 F. Fuso, M. Bassu, F. Tantussi, L.Strambini, G. Barillaro, M. Allegrini
Emission from Silicon/Gold nanoparticle systems
CP 67 I.Ulfat, J. Adell, J. Sadowski, L. Ilver, J. Kanski
As3d Core Level Phooemission Studies of (GaMn)As annealed under As capping
CP 68 N. Alinejad, M. Jahangir, F. Izadi
Pulsed laser Deposition Simulation for Graphite Target using Mont-Carlo Method
CP 69 C. Diehl, D. Pinegar, R. S. Van Dyck Jr, K. Blaum
Precision Measurement of the 3He-3H mass ratio with the MPIK/UW-PTMS
CP 70 A. Alonso-Medina, C.Colón, C. Herrán-Martínez
Measured of different atomic parameters of some elements (Ca, Sn, Pb) in a plasma generated by
Laser-Induced Breakdown Spectroscopy (LIBS)
CP 71 T. Carette, C. Drag, C. Blondel, C. Delsart, C. Froese Fischer, M. Godefroid, O. Scharf
Isotope shift in the electron affinity of sulfur
CP 72 A.K. Kazansky, N.M. Kabachnik
Theoretical study of attosecond chronoscopy of strong-field atomic photoionization
CP 73 A.V. Glushkov, O.Y.Khetselius, A.V. Loboda
Generation of ultra-short X-ray pulses in cluster system during ionization by femto-second optical
pulse
CP 74 J. Alnis, A. Matveev, T. W. Hänsch, C. Parthey, N. Kolachevsky
Long-term stability of high-finesse Fabry-Perot resonators made from Ultra-Low-Expansion glass
CP 75 H.-D. Kronfeldt, H. Schmidt
Application of Surface-Enhanced-Raman-Scattering (SERS) for In-Situ Detection of PAHs in
Sea-Water
CP 76 S. Qamar Hussain, M. Saleem, A. Baig
Laser Based Isotopic Separation of Atoms
CP 77 D. Gleeson, V. Minogin, S. Nic Chormaic
Atomic fluorescence coupled into a thin optical fibre
CP 78 D.U. Matrasulov, T.A. Ruzmetov, D.M. Otajanov, P.K. Khabibullaev, A.A. Saidov, F.C. Khanna
Nonlinear dynamics of atoms in a cavity
CP 79 G.G. Grigoryan, Y. Pashayan-Leroy, C. Leroy, S. Guèrin
Storage of optical pulses in solids despite fast relaxation
CP 80 M. Motsch, M. Zeppenfeld, G. Rempe, W. Pinkse
Purcell-enhanced Rayleigh scattering into a Fabry-Perot cavity
CP 81 M. Agre
Cicular and elliptical dichroism effects in two-photon disintegration of atoms and molecules
CP 82 I. L. Glukhov, V. D. Ovsiannikov
Thermal ionization of alkali Rydberg atoms
CP 83 V.D.Ovsyannikov, E. Yu.Ilinova
Hyperpolarizabilities of multiplet Rydberg states in alkali and alkaline-earth atoms
CP 84 N. N. Bezuglov,, K. Miculis, A. Ekers, J. Denskat, C. Giese, T. Amthor, M. Weidemueller
Penning ionization of cold Rb Rydberg atoms due to long-range dipole-dipole interaction
242
CP 85 I.I.Beterov, I.I. Ryabtsev, D.B. Tretyakov, N.N Bezuglov, A. Ekers, V.M. Entin
Ionization of alkali-metal Rydberg atoms by blackbody radiation
CP 86 B. T. Torosov, N.V. Vitanov
Level-crossing transition between mixed states
CP 87 S.Werbowy, J. Kwela
M1-E2 interference in the Zeeman spectra of Bi I
CP 88 E. Efremova, G. Anisimova, R. Semenov, G. Tsygankova
Numerical investigation of Ne I for 2p55g configuration and Ar I for 3p55g configuration Zeeman
structure
CP 89 A. Papoyan, G. Hakhumyan, A. Atvars, M. Auzinsh, D. Sarkisyan
Method for quantitative study of atomic transitionsin magnetic field based on vapor nanocell with
L = λ
CP 90 D. Glazov, A. Volotka, V. Shabaev, I. Tupitsyn, G. Plunien
g factor of boronlike ions
CP 91 V. Chernushkin, V. Ovsiannikov
Magnetoelectric Jones spectroscopy of Li and Na atoms
CP 92 A. Kamenski, V. Ovsiannikov
Radiative transition probabilities from D Stark states in orthohelium
CP 93 M. Ryabinina, L. Melnikov
Light-induced quasi-static polarization in hydrogen-like atom under the action of strong
electromagnetic laser field
CP 94 G.Skolnik, N. Vujicic, T. Ban, S. Vdovic, G. Pichler
Doppler-free spectroscopy of rubidium atoms placed in a magnetic field
CP 95 M. Pawlak, M. Bylicki
Electric field influence on the hydrogen atom embedded in a plasma
CP 96 B. Schnizer, Th. Heubrandtner, E. Rössl, M. Musso
Dynamic and geometric phases in the Stark Zeeman effect of the hyperfines structure of one-electron
atoms
CP 97 A. Costescu, C. Stoica, S. Spanulescu
New analytical relativistic formulae for the total photoeffect cross section for the K-shell electrons
CP 98 N.L. Manakov, S.I. Marmo, S.Sviridov
Two-photon above-threshold ionization by a VUV-light
CP 99 N.L. Manakov, S.I. Marmo, S.Sviridov
Above-threshold polarizability of alkali-metal and noble gas atoms
CP 100 V. Richardson, J. Dardis, P. Hayden, P. Hough, E.T. Kennedy, J.T. Costello, S. Dsterer, W. Li,
A. Azima, H. Redlin, J. Feldhaus, D. Cubaynes, D. Glijer, M. Meyer
Ionisation in Intense Superposed XUV + NIR Laser Fields
CP 101 V.L.Sukhorukov, I.D. Petrov, H. Hotop
Photoionization of excited rare gas atoms Rg(mp5(m+1)p J=0-3) in the autoionization region
CP 102 S.Y. Yousif Al-Mulla
Spin dependent exchange scattering from ferromagnetic materials
CP 103 K. Alioua , M. Bouledroua, A. Allouche, and M. Aubert-Frécon
Far-wing collisionnal broadening of the Na(3s-3p) line by helium
CP 104 S. Chelli, M. Bouledroua
Excited and ground potassium monatoms perturbed by helium
CP 105 L. Reggami, M. Bouledroua
Pressure broadening of calcium resonance line perturbed by helium
CP 106 E. Saks, I. Sydoryk, N. N. Bezuglov, I. I. Beterov, K. Miculis, A. Ekers
Broadening and intensity redistribution in the atomic hyperfine excitation spectra due to optical
pumping in the weak excitation limit
243
CP 107 B. Mahrov, C. Andreeva, N. Bezuglov, K. Miculis, E. Saks, M. Bruvelis, A. Ekers
Reconsideration of spectral line profiles affected by transit time broadening
CP 108 G. Auböck, J. Nagl, C. Callegari, W.E. Ernst
Alkali doped Helium Droplets in a Magnetic Field
CP 109 J. Nagl, G. Auböck, A.W. Hauser, O. Allard, C. Callegari, W.E. Ernst
Quartet alkali trimers on He nanodroplets: Laser spectroscoy and ab initio calculations
CP 110 R. Hefferlin
Group Dynamics of 2-Atom Even-Electron Molecules and Ions
CP 111 A. Dantan, P. Herskind, J. Marler, M. Albert, M.B. Langkilde-Lauesen, M. Drewsen
11:30 Cavity-QED with ion Coulomb crystals
CP 112 U. Hohenester, A. Eiguren, S. Scheel, E.A. Hinds
11:45 Spin flip lifetimes in superconducting atom chips
CP 113 A. Cerè, V. Parigi, M. Abad, F. Wolfgramm, A. Predojevic, M. Mitchell
12:00 Interaction-Free Measurement of the Degree of Polarization of an Atomic Ensemble
CP 114 J. Koperski, M. Krosnicki, M. Strojecki
12:15 Entangled atom-pairs from dissociated dimers: an experimental test of Bell inequality for atoms
CP 115 G. Casa, A. Castrillo, G. Galzerano, R. Wehr, A. Merlone, D. Di Serafino, P. Laporta, L.Gianfrani
11:00 Primary gas thermometry by means of near-infrared laser absorption spectroscopy and determination
of the Boltzmann constant
CP 116 V. Batteiger, M. Herrmann, S. Knünz, A. Ozawa, A. Vernaleken, G. Saathoff, M. Semczuk, F. Zhu,
H. Schuessler, Th. Hänsch, T. Udem
11:15 Towards precision spectroscopy in the XUV
CP 117 P.F. Staanum, K. Hojbjerre, R. Wester, M. Drewsen
11:30 Probing isotope effects in chemical reactions using single ions
CP 118 N.A. Matveeva, A.V. Taichenachev, A.M. Tumaikin, V.I. Yudin
11:45 Laser cooling of unbound atoms in nondissipative optical lattice
CP 119 R. Lammegger, E. Breschi, G. Kazakov, G. Mileti, B. Matisov, L. Windholz
11:30 Investigations on the lin||lin CPT and its application in quantum sensors
CP 120 J. Klein, F. Beil, T. Halfmann
11:45 Optically Driven Atomic Coherences: from the gas phase to the solid state
CP 121 F. A. Hashmi, M. A. Bouchene
12:00 Slowing light and coherent control of susceptibility in a duplicated two-level system
CP 122 T. Pfau, R. Heidemann, U. Raitzsch, V. Bendkowsky, B. Butscher, R. Löw
12:15 Rydberg excitation of a Bose-Einstein Condensate
CP 123 S. Kreim, K. Blaum, H. Kracke, A. Mooser, W. Quint, C. Rodegheri, S. Ulmer, J. Walz
11:30 Progress towards a high-precision measurement of the g-factor of a single, isolated (anti)proton in a
double Penning trap
CP 124 R. E. Zillich, M. Leino, A. Viel
11:15 Helium-4 Clusters Doped with Excited Rubidium Atoms
CP 125 M. Koch, J. Lanzersdorfer, G. Auböck, J. Nagl, C. Callegari, and W. E. Ernst
11:30 Progress in optically-detected spin-resonance on helium droplets
CP 126 I.I. Ryabtsev, D.B. Tretyakov, I.I. Beterov, V.M.Entin
11:45 Effect of finite detection efficiency on the observation of the dipole-dipole interaction of a few
Rydberg atoms
CP 127 A.V. Glushkov, O.Yu. Khetselius, S.V. Malinovskaya, Yu. V. Dubrovskaya
Energy approach to discharge of metastable nuclei during negative muon capture
CP 128 A.V. Glushkov
Resonance phenomena in heavy ions collisions and structurization of positron spectrum
CP 129 O.Y. Khehtselius
Dynamics of the resonant levels for atomic and nuclear ensembles in a laser pulse: optical bi-stability
effect and nuclear quantum optics
244
CP 130 A.V. Glushkov, O.Y.Khetselius, E.P. Gurnitskaya, Yu. V. Dubrovskaya, D.E. Sukharev
Spectroscopy of the hadronic atoms and superheavy ions: Spectra, energy shifts and widths, hyperfine
structure
CP 131 K. Katsonis, Ch. Berenguer, R. Srivastava, L. Sharma, R. Clark, M. Cornille, A.D. Stauffer
Ar I transition probabilities and excitation cross sections involving the 4s metastable levels and the
4/5p configurations
CP 132 G. Malcheva, K. Blageov, R. Mayo, M. Ortiz, J. Ruiz, L. Engström, H. Lundberg, S.Svanberg,
H. Nilsson, P. Quinet, E. Biémont
Radiative data in the Zr I spectrum
CP 133 G.P. Gupta
Engergy levels, oscillator strengths and lifetimes in C1 IV
CP 134 G.P. Gupta
Large scale CIV 3 calculations of fine-structure energy levels and lifetimes in Al-like copper
CP 135 C. Colon, A. Alonso-Medina, A. Zanon, J. Albeniz
Levels energies, oscillator strengths, and lifetimes for transition in Pb III
CP 136 E. Träbert
Hyperfine interaction induced decays in highly charged ions
CP 137 A. Stepanov
Einstein coefficients for activation barriers of equilibrium and non-equilibrium processes caused by
Plank radiation
CP 138 V. Fivet, E. Biemont, P. Palmeri, P. Quinet
New transition probabilities of astrophysical interest in triply ionized lanthanum (La IV)
CP 139 J. Gurell, P. Lundin, S. Mannervik. L.O.Norlin, P. Royen
A new method for determining minute long lifetimes of metastable levels
CP 140 J. Gurell, P. Lundin, S. Mannervik. L.O.Norlin, P. Royen, P. Schef, H. Hartman, A. Hibbert,
H. Lundberg, K. Blageov, P. Palmeri, P. Quinet, E. Biémont
Lifetime measurements of metastable states of astrophysical interest
CP 141 M.-T. Lee, M. Fujimoto, S. Michelin, I. Iga
Spin-exchange effects in elastic electron scattering from linear triatomic radicals
CP 142 S. Zapryagaev, E.Butyrskaya
Spectral properties of interactions in endohedral fullerenes Li2@c60 and Na2@C60
CP 143 S. Zapryagaev, E.Butyrskaya
Simulation of fullerene formation
CP 144 I.I.Shafranyosh, M.I.Sukhoviya, M.I.Shafranyosh, R.O. Fedorko
Cross sections of negative ion poduction in electron collisions with Adenine molecules
CP 145 O. Ryazanova, O. Nesterov, V. Zozulya
Effect of divalent metal ions on the conformational transitions in poly(dA)+poly(dT) system
CP 146 K. Hubisz, T. Wroblewski, V.I. Tomin
Anomalous inhomogeneous broadening and kinetics properties of DMABN
CP 147 L. Pruvost, H. Jelassi, B. Viaris de Lesegno
Reexamination of the LeRoy-Bernstein formula for weakly bound molecules
CP 148 F. Talbi, M. Bouledroua, K. Alioua
The singlet X -A and X -B absorption coefficient of the K2 system
CP 149 A. W. Hauser, C. Callegari, W.E. Ernst, P. Soldán
Atomic-like shell models for alkali trimers derived from ab initio calculations
CP 150 L. Busevica, R. Ferber, O. Nikolayeva, E. Pazyuk, A. Stolyarov, M. Tamanis
First observation and analysis of the (1; 2)1Π states of KCs
CP 151 O. Nikolayeva, R. Ferber, M. Tamanis, K. Knöckel, E. Tiemann, A. Pashov
High resolution spectroscopy and IPA potential construction of a3Σ+ state in KCs
245
CP 152 J. Heldt, M. Józefowicz. J. R. Heldt
Determination of first-order molecular hyperpolarizability of
ethyl 5-(4-aminophenyl)-3-amino-2,4-dicyanobenzoate using steady-state spectroscopic
measurements and quantum-chemical calculations
CP 153 L.E. Sansores, J. Muniz, A. Martinez, R. Salcedo
Electronic structure of the [Au2(dmpm)(i - mnt)] complex
CP 154 T. L. Dimitrova, A. Weis
A lecture demonstration of quantum erasing on a photon by photon basis
CP 155 J.L. Robyr, P. Knowles, A. Weis
Stark shift in the Cs clock transition frequency
CP 156 P. Knowles, G. Bison, N. Castagna, A. Hofer, A. Mtechdlishvili, A. Pazgalev, A. Weis
Magnetic Field Imaging With Arrays of Cs Magnetometers: Technology and Applications
CP 157 R. Lammegger, L.Windholz
Performance of a compact dark state Magnetometer
CP 158 A. Litvinov, G. Kazakov, B. Matisov
Laser-induced transport effect and laser induced-line narrowing mechanism for laser excitation in
87Rb atomic vapors in a finite-size buffer-less cell
CP 159 G.G. Grigoryan, G. Nikoghosyan, A. Gogyan, Y.T. Pashayan-Leroy, C. Leroy, S. Guerin
Population transfer, light storage, and superluminal propagation by bright-state adiabatic passage
CP 160 C. Andreeva, N. Bezuglov, A. Ekers, K. Miculis, B. Mahrov, I. Ryabtsev, E. Saks,
R. Garcia-Fernandez, K. Bergmann
Population switching of Na and Na2 excited states by means of interference due to Autler-Townes
effect
CP 161 E. Alipieva, E. Taskova, S. Gateva, G. Todorv
High-rank polarization moments influence on the CPT resonance obtained on two-level degenerated
system
CP 162 K. Vaseva, P. Todorov, S. Caraleva, D. Slavov, S. Saltiel
Sub-Doppler fluorescence spectroscopy of Cs-vapour layers with nano-metric thickness
CP 163 P. Todorov, S. Cartaleva, K. Vaseva, C. Andreeva, I. Maurin, D. Slavov, S. Saltiel
Absorption in the saturation regime of Cs-vapour layer with thickness close to the light wavelength
CP 164 M. Auzins, R. Ferber, I. Fescenko, L. Kalvans, M. Tamanis
Dark and bright resonances in large J systems
CP 165 M. Auzinsh, R. Ferber, F. Gahbauer, A. Jarmola, L. Kalvans
F-resolved bright and dark magneto-optical resonances at the cesium D1 line
CP 166 T. Kirova, A. Ekers, N. N. Bezuglov, I. I. Ryabtsev, K. Blushs, M. Auzinsh
Effects of hyperfine structure on the Autler-Townes splitting
CP 167 A.Sargsyan, M.G. Bason, D. Sarkisyan, Y. Pashayan-Leroy, A.K. Mohapatra, C.S. Adams
Ladder and lambda systems electromagnetically induced transparency in thin and extremely-thin
cells
CP 168 A. Sargsyan, D. Sarkisyan, A. Papoyan,Y. Pashayan-Leroy, C.Leroy, P. Moroshkin. A. Weis
Saturation effects of Faraday rotation signals in Cs vapor nanocells: thickness-dependend effects
CP 169 L. Kalvans, M. Auzinsh, R. Ferber, F. Gahbauer, A. Jarmola, A. Papoyan, D. Sarkisyan
Magneto-optical resonances in atomic rubidium at D1 excitation in ordinary and extremely thin cells
CP 170 A.Y. Samokotin, A.V. Akimov, N.N. Kolachevsky, Y. V. Vladimirova, V.N. Zadkov, A.V. Sokolov,
V. N. Sorokin
Frequency-modulation spectroscopy of coherent population trapping resonances
CP 171 K. Dahl, L. Spani, R.H. Rinkleff, K. Danzmann
Pump-probe spectroscopy: a survey of the spectra for four polarization combintations in degenerate
two-level atoms
CP 172 Z. Grujic, M. Mijailovic, D. Arsenovic, M. Radonjic, B. M. Jelenkovic
Dark resonance narrowing in uncoated rubidium vacuum vapor cell
246
CP 173 S. S. Ivanov, P. Ivanov, N. Vitanov
Quantum search with trapped ions
CP 174 G. von Oppen
The observability of atoms
CP 175 T. Leveque, A. Gauguet, W. Chaibi, A. Landragin
Characterization of a high precision cold atom gyroscope
CP 176 F. Shojaei Baghini, M. A. Bolorizadeh, R. Fathi, E. Ganhbari Adivi
Electron capture of methane molecule by proton impact
CP 177 Ch.Berenguer, K. Katsonis, R. Srivastava, L. Sharma, R. Clarks, A.D. Stauffer
Excitation of the Xe I 6s metastables to the 6p and 7p configurations
CP 178 G. P. Anisimova, E. Efremova, G. A. Tsygankova
Parametrization of Ne I spectrum for 2p55g, 6g, 7g configurations using semiempirical method
CP 179 R. Karpuskiene, P. Bogdanovich, O. Rancova
Ab initio calculations of aluminium-like calcium
CP 180 T.J. Wasowicz, S. Werbowy, R. Drozdowski, J. Kwela
Isotope shifts of forbidden lines of Lead
CP 181 P. Moroshkin, V. Lebedev, A. Weis
Solid 4He stabilized by charged impurities below the solidification pressure of pure helium
CP 182 P. Moroshkin, V. Lebedev, A. Weis
Spectroscopy of Ba atoms isolated in solid He matrix
CP 183 A. Matveev, J. Alnis, C. Parthey, N. Kolachevsky, T. W. Hänsch
New Measurement of the 2S Hyperfine Splitting in Atomic Hydrogen
CP 184 Yu.P. Gangrsky, K.P. Marinova, S.G. Zemlyanoi, M. Avogoulea, J. Billowes, P. Campbell, B. Cheal,
B. Tordoff, M. Bissel, D.H. Forest, M. Gardner, G. Tungate, J. Huikari, H. Penttila , J Aysto
High Resolution Laser Spectroscopy of Scandium
CP 185 S. Poonia
Lα1, Lα2, Lβ1, Lβ2 and Lγ satellites in the X-Ray emission spectra
CP 186 S. Poonia
Origin of X-Ray satellites spectra in the Lα1 and Lα2 region
CP 187 H.P. Garnir, E. Biemont, S. Enzonga Yoca, P. Quinet
VUV Spectroscopy of Xe IX
CP 188 V. Fivet, E. Biémont, P. Palmeri, P Quinet, L. Engström, H. Lundberg, H. Nilsson
Improved atomic data for platinum group elements
CP 189 F. Gilleron, J. c. Pain, J. Bauche, C. Bauche-Arnoult
Impact of high-order moments on the statistical modeling of transition arrays
CP 190 J. C. Pain, F. Gilleron
Exact and statistical methods for computing the distribution of states, levels and E1 lines in atomic
spectra
CP 191 Y.Nighat, R. Islam
Laser optogalvanic spectroscopy of Lanthanum in Spectral range of Rhodamine 6 G
CP 192 A. Nadeem
Investigation of the even parity states of group II-B elements (Zn, Cd and Hg)
CP 193 Z. Uddin, L. Windholz, F. Akber, M . Jahangir, I. Siddiqui
New levels of Pr I discovered via infrared spectral lines
CP 194 A. Er, I.K. Öztürk, Gö. Basar, S. Kroeger, Gü. Basar, A. Jarmola, M. Tamanis, R. Ferber
New lines of atomic niobium in Fourier transform spectra
CP 195 J. Dembczynski, M. Elantkowska, J. Ruczkowski
Configuration interaction effects in the fine- and hyperfine structure of the even configuration system
of tantalum atom
247
CP 196 E. Stachowska, J. Dembczynski, L. Windholz
Extended analysis of the even configurations of Ta II
CP 197 B. Furmann
Search for new electronic levels in singly ionized europium Eu II
CP 198 B. Acrimowicz, J. Dembczynski
Analysis of the odd configurations of tantalum atom – search for configurations containing f electrons
CP 199 J. Dembczynski, M. Elantkowska, J. Ruczkowski
Program package for semi-empirical analysis of the fine- and hyperfine structure of complex atoms
CP 200 M. Elantkowska, J. Ruczkowski, J. Dembczynski
Procedure for precise determination of the hyperfine structure constants A, B, C and D. Example of
lanthanum atom
CP 201 B. Gamper, L. Windholz
Investigations of the Hyperfinestructure of Praseodymium in the IR-Region with the help of FTS
CP 202 P. Glowacki, L. Windholz, J. Dembczynski
Investigation of the hyperfine structure of Ta I - - lines
CP 203 I. Siddiqui, B. Gamper, G.H. Guthöhrlein, L.Windholz
Perturbed intensity distribution of hyperfine components of Praseodymium-I lines
CP 204 S. Khan, S.T. Iqbal, I. Siddiqui, L. Windholz
Investigation of the hyperfine structure of Pr I - lines in the region 5630 Å to 5772 Å
CP 205 G. Krois, G.H. Guthöhrlein, L. Windholz
Correction of Pr I energy level values due to Fourier transform spectra and laser excitation
CP 206 H. Reschab, C. Cagran, R. Tanzer, W. Schützenhöfer, A. Graf, G. Pottlacher
Normal spectral emissivity depending on atomic composition for two nickel-based and two ferrousbased
alloys at 684.5 nm
CP 207 T. Hüpf, C. Cagran, G. Pottlacher, G. Lohöfer
Identification of atomic structure in measurement data, depending on the used set of units
CP 208 S. Cohen, M. M. Harb, A. Ollagnier, S. Cohen, F. Lepine, F. Robicheaux, M. Vrakking, C. Bordas
Electronic Wavefunction Microscopy using slow-photoelectron Imaging
CP 209 E. Dimova, D. Zhechev, V. Steflekova
On a self-sustained oscillating mode for operation of a glow discharge
CP 210 A. Kortyna and V. Fiore
Atomic beam measurements of the Cs 7d 2D3/2 hyperfne parameters with two-photon fluorescence
spectroscopy
CP 211 O.B.Shpenik, E.E. Kontros, I.V. Chernyshova
Electron scattering by Cadmium atoms
CP 212 W. Steurer, B. Holst, J.R. Manson, W.E. Ernst
Probing surface vibrations of amorphous solids by helium atom scattering
CP 213 B. Brandstätter, B. Hemmerling, L. An der Lan, P.O. Schmidt
Towards Direct Frequency Comb Spectroscopy using Quantum Logic
CP 214 M. Niedermayr, M. Kumph, Piet Schmidt, Rainer Blatt
Towards Cryogenic Surface Ion Traps
CP 215 I. Iga, I. P. Sanches, R. T. Sugohara , M. G. P. Homem and M. T. Lee
Cross sections for elastic electron collisions with small alcohols
248
Author Index
Abad M CP 113
Abdoul R. CP 62
Acrimowicz B. CP 198
Adams C.s. CP 167
Adell J. CP 67
Agre M.Ya. CP 81
Akber F. CP 193
Akimov A. CP 61
Akimov A. CP 63
Akinov A.V. CP 170
Albéniz J. CP 135
Albert M CP 111
Alinejad N. CP 68
Alioua K. CP 103
Alioua K. CP 148
Alipieva E. CP 161
Allard O. CP 109
Allegrini M. CP 65
Allegrini M CP 66
Allouche A. CP 103
Alnis J. CP 183
Alnis J. CP 74
Alonso-Medina A. CP 70
Alonso-Medina A. CP 135
Amthor T. CP 84
Ancarani L.U. CP 9
Ancarani L.U. CP 15
Ancarani L.U. CP 26
Ancarani L.U. CP 27
An der Lahn L. CP 213
Andersson P. CP 42
Andreeva C. CP 107
Andreeva C. CP 160
Andreeva C. CP 163
Andreeva E.V. CP 24
Anisimova G.P. CP 88
Anismova G.P. CP 178
Arimondo E. CP 65
Arsenovic D. CP 172
Aspect A. CP 57
Atvars A. CP 89
Aubert-Frécon M. CP 103
Auböck G- CP 108
Auböck G. CP 109
Auböck G. CP 125
Auzinsh M. CP 89
Auzinsh M. CP 164
Auzinsh M. CP 165
Auzinsh M. CP 166
Auzinsh M CP 169
Avgoulea M. CP 184
Aymar M. CP 3
Aysto J. CP 184
Azima A. CP 100
Baig M.A. CP 76
Ban T. CP 94
Banás D. CP 43
Bandi T.N. CP 7
Bandurina L. CP 44
Barillaro G. CP 66
Barker P.F. PR 6
Basar Gü. CP 194
Basar Gö. CP 194
Bason M.G. CP 167
Bassu M. CP 66
Baszanowska E. CP 45
Batteiger V. CP 116
Bauche J. CP 189
Bauche-Arnoult C. CP 189
Beaufils Q. CP 53
Becker Th. CP 8
Becker U. PR 4
Beil F. CP 120
Bendkowsky V. CP 122
Bengtsson J. CP 12
Bengtsson J. CP 25
Beninger M. CP 1
Benseddik C. CP 49
Berenguer Ch. CP 131
Berenguer Ch. CP 177
Bergmann K. CP 160
Berset M CP 43
Beterov I.I. CP 51
Beterov I.I. CP 85
Beterov I.I. CP 106
Beterov I.I. CP 126
Bezuglov N.N. CP 84
Bezuglov N.N. CP 85
Bezuglov N.N. CP 106
Bezuglov N.N. CP 107
Bezuglov N. CP 160
Bezuglov N.N. CP 166
Biémont E. CP 132
Biémont E. CP 138
Biémont E. CP 140
Biémont E. CP 187
Biémont E. CP 188
Bieron J. CP 11
Billowes J. CP 184
Bison G. CP 156
Bissel M. CP 184
Blagoev K. CP 132
Blagoev K. CP 140
Blatt R. CP 214
Blaum K. CP 6
Blaum K. CP 69
Blaum K. CP 123
Blondel C. PL 9
Blondel C. CP 71
Blushs K. CP 166
Bogdanovic P. CP 21
Bogdanovic P. CP 179
Bolorizadeh M.A. CP 28
Bolorizadeh M.A. CP 176
Bordas C. CP 208
Bouazza M.T. CP 49
Bouazza M.T. CP 50
249
Bouchene M.A. CP 121
Bouledroua M. CP 49
Bouledroua M. CP 50
Bouledroua M. CP 103
Bouledroua M. CP 104
Bouledroua M. CP 105
Bouledroua M. CP 148
Bourdel T. CP 57
Bouyer P. CP 57
Brandstätter B. CP 213
Brantut J.P. CP 57
Brescansin L.M. CP 33
Breschi E. CP 119
Bruvelis M. CP 107
Busevica L. CP 150
Butscher B. CP 122
Butyrskaya E.V. CP 142
Butyrskaya E.V. CP 143
Bylicki M. CP 95
Cagran C. CP 206
Cagran C. CP 207
Callegari C. CP 108
Callegari C. CP 109
Callegari C. CP 125
Callegari C. CP 149
Campbell P. CP 184
Carette T. CP 71
Cartaleva S. CP 162
Cartaleva S CP 163
Casa G. CP 115
Castagna N. CP 156
Castrillo A. CP 115
Cerè A. CP 113
Chaeal B. CP 184
Chaibi W.E. CP 175
Chaibi W. PL 9
Champenois C. PR 2
Champion C. CP 34
Chebakov K. CP 61
Chelli S. CP 104
Chernushkin V.V. CP 91
Chernyshova I.V. CP 211
Chicireanu R. CP 53
Chmielewska D. CP 43
Chwirot S. CP 48
Clark R.E.H. CP 131
Clark R.E.H. CP 177
Clément J.F. CP 57
Cohen S. CP 208
Colavecchia F.D. CP 27
Colón C. CP 135
Colón C. CP 70
Corkum P. PL 10
Cornille M. CP 131
Costello J.T. CP 100
Costescu A. CP 97
Crespo Lopez-U. J.R. PR 7
Crubellier A. CP 53
Cubaynes D. CP 100
Curl R.F., jr. EL 1
Czarnota M. CP 43
Dahl K. CP 171
Dal Cappello C. CP 27
Dal Cappello C. CP 34
Dantan A. CP 111
Danzmann K. CP 171
Dardis J. CP 100
de St. Vincent M.R. CP 57
Deiglmayr J. CP 3
Delsart C. CP 71
Delsart C. PL 9
Dembczynski J. CP 195
Dembczynski J. CP 196
Dembczynski J. CP 198
Dembczynski J. CP 199
Dembczynski J. CP 200
Dembczynski J. CP 202
Denskat J. CP 84
Desouter-Lecomte M. CP 37
di Serafino D. CP 115
Diehl Ch. CP 6
Diehl C. CP 42
Diehl Ch. CP 69
Dimitrova T.L. CP 154
Dimova E. CP 209
Diry F. CP 52
Dmitriev S.P. CP 46
Dousse J.Cl. CP 43
Dovator N.A. CP 46
Drag C. CP 71
Drag C. PL 9
Drewsen M. CP 111
Drewsen M. CP 117
Drozdowski R. CP 45
Drozdowski R. CP 180
Dsterer S. CP 100
Dubrovskaya Yu.V. CP 127
Dubrovskaya Yu.V. CP 130
Dulieu O. CP 3
Dzhurakhalov A.A. CP29
Dziczek D. CP 48
Efremova E.A. CP 88
Efremova E.A. CP 178
Egorov M. CP 63
Ehresmann A. CP 20
Eiguren A. CP 112
Ekers A. CP 84
Ekers A. CP 85
Ekers A. CP 106
Ekers A. CP 107
Ekers A. CP 160
Ekers A. CP 166
Elantowska M. CP 195
Elantowska M. CP 199
Elantowska M. CP 200
Engström L. CP 132
Engström L. CP 188
Entin V.M. CP 51
Entin V.M. CP 85
Entin V.M. CP 126
250
Enzonga Yoca S. CP 187
Epp S.W. PR 7
Er A. CP 194
Erbert G. CP 5
Ernst W.E. CP 108
Ernst W.E. CP 109
Ernst W.E. CP 125
Ernst W.E. CP 149
Ernst W.E. CP 212
Fathi R. CP 28
Fathi R. CP 176
Fedorko R.O. CP 144
Fedorko R.O. CP 31
Feldhaus J. CP 100
Ferber R. CP 150
Ferber R. CP 151
Ferber R. CP 164
Ferber R. CP 165
Ferber R. CP 169
Ferber R. CP 194
Ferlaino F. CP 1
Fescenko I. CP 164
Fiore V. CP 210
Fivet V. CP 138
Fivet V. CP 188
Forest D.H. CP 184
Forstner O. CP 42
Fritzsche S. CP 11
Froese Fischer C. CP 71
Fröhlich B. CP 60
Fujimoto M.M CP 141
Furmann B. CP 197
Fuso F. CP 65
Fuso F. CP 66
Gahbauer F. CP 165
Gahbauer f. CP 169
Gaidamauskas E. CP 10
Gaidamauskas E. CP 11
Gaigalas G. CP 10
Gaigalas G. CP 11
Galzerano G. CP 115
Gamper B. CP 201
Gamper B. CP 203
Gangersky Yu.P. CP 184
Garcia-Fernandez R. CP 160
Gardner M. CP 184
Garnir H.P. CP 187
Gartman R. CP 62
Gartman R. CP 64
Gasaneo G. CP 9
Gasaneo G. CP 15
Gasaneo G. CP 26
Gasaneo G. CP 27
Gateva S. CP 161
Gauguet A. CP 175
Gawlik W. CP 62
Gawlik W. CP 64
Gedeon S. CP 36
Gedeon V. CP 44
Germann Th. CP 8
Ghanbari Adivi E. CP 28
Ghanbari Adivi E. CP 176
Giafrani L. CP 115
Giese C. CP 84
Gilleron F. CP 189
Gilleron F. CP 190
Glazov D.A. CP 22
Glazov D.A. CP 90
Gleeson D. CP 77
Glijer D. CP 100
Glowacki P. CP 202
Glukhov I.L. CP 82
Glushkov A.V. CP 17
Glushkov A.V. CP 18
Glushkov A.V. CP 73
Glushkov A.V. CP 127
Glushkov A.V. CP 128
Glushkov A.V. CP 130
Gochitashvili M. CP 30
Godefroid M. CP 71
Gogyan A. CP 159
Gomonai A. CP 41
Gonzalez V.Y. CP 15
Gonzalez V.Y. CP 9
Gorceix O. CP 53
Gorceix O. CP 59
Graf A. CP 206
Griesmaier A. CP 60
Grigoryan G.G. CP 79
Grigoryan G.G. CP 159
Grimm R. CP 1
Grimm R. PR 5
Grond J. CP 55
Grujic Z. CP 172
Gudym V.K. CP 24
Guérin S. CP 159
Guérin S. CP 79
Gupta G.P. CP 133
Gupta G.P. CP 134
Gurell J. CP 139
Gurell J. CP 140
Gurnitskaya E.P. CP 130
Guthöhrlein G.H. CP 203
Guthöhrlein G.H. CP 205
Hagel G. PR 2
Hakhumyan G. CP 89
Halfmann T. CP 120
Hänsch T.W. CP 8
Hänsch T.W. CP 74
Hänsch T.W. CP 116
Hänsch T.W. CP 183
Hanstorp D. CP 42
Harb M.M. CP 208
Haroche S. PL 1
Hartman H. CP 140
Hashmi F.A. CP 121
Hauser A.W. CP 109
Hauser A.W. CP 149
Hayden P. CP 100
Hecker-Denschlag J. PR 5
251
Hefferlin R. CP 110
Heidemann R. CP 122
Heldt J. CP 152
Heldt J.R. CP 152
Hemmerling B. CP 213
Herrán-Martínez C. CP 70
Herrmann M. CP 116
Herskind P. CP 111
Heubrandtner Th. CP 96
Hibbert A. CP 140
Hinds E.A. CP 112
Hitawala U. CP 38
Hofer A. PL 6
Hofer A. PL 6
Hohenester U. CP 54
Hohenester U. CP 55
Hohenester U. CP 112
Hojbjerre K. CP 117
Holst B. CP 212
Homem M.G.P. CP 215
Hoszowska J. CP 43
Hotop H. CP 101
Houamer S. CP 34
Hough P. CP 100
Houssin M. PR 2
Hubisz K. CP 146
Huikari J. CP 184
Hüpf Th. CP 207
Hussain S.Q. CP 76
Hutych Yu. CP 41
Iga I. CP 33
Iga I. CP 141
Iga I. CP 215
Ilinova E.Yu. CP 83
Ilver L. CP 67
Imre A. CP 41
Islam R. CP 191
Ivanov S. CP 173
Ivanov P. CP 173
Izadi F. CP 68
Jahangiri M. CP 68
Jahangir M CP 193
Jarmola A. CP 165
Jarmola A. CP 169
Jarmola A. CP 194
Jelassi H. CP 2
Jelassi H. CP 147
Jelenkovic B.M CP 172
Jiang D. CP 13
Johnson W.R. CP 14
Jönsson P. CP 11
Józefowicz M. CP 152
Jursenas R. CP 23
Kabachnik N.M. CP 72
Kalvans L. CP 164
Kalvans L. CP 165
Kalvans L. CP 169
Kamenski A.A. CP 92
Kaminski P. CP 45
Kanorsky S. CP 61
Kanski J. CP 67
Karpuskiene R. CP 21
Karpuskiene R. CP 179
Kartoshkin V.A. CP 46
Kartoshkin V.A. CP 47
Kashuba A.S. CP 35
Katsonis K. CP 131
Katsonis K. CP 177
Kazakov G. CP 119
Kazakov G. CP 158
Kazansky A.K. CP 72
Keller J.C. CP 53
Keller J.C CP 59
Kennedy E.T. CP 100
Khabibullaev P.K. CP 78
Khan Sh. CP 204
Khanna F.C. CP 78
Khetselius O.Yu. CP 16
Khetselius O.Yu. CP 17
Khetselius O.Yu. CP 73
Khetselius O.Yu. CP 127
Khetselius O.Yu. CP 129
Khetselius O.Yu. CP 130
Kienberger R. PR 9
Kirova T. CP 166
Klein J. CP 120
Klosowski L. CP 48
Kluge H.-J. PL 3
Klumpp S. CP 20
Knöckel K. CP 151
Knöckl H. CP 58
Knoop S. CP 1
Knoop M. PR 2
Knowles P. CP 155
Knowles P. CP 156
Knünz S. CP 116
Koch M. CP 125
Koch T. CP 60
Kolachevsky N. CP 61
Kolachevsky N. CP 63
Kolachevsky N. CP 74
Kolachevsky N. CP 170
Kolachevsky N. CP 183
Kontros E.E. CP 211
Koperski J. CP 114
Kortyna A. CP 210
Kozhedub Y.S. CP 22
Kozlov M.G. CP 14
Kracke H. CP 123
Kreim S. CP 123
Kröger S. CP 194
Krois G. CP 205
Kronfeldt H.D. CP 5
Kronfeldt H.D. CP 75
Krosnicki M. CP 114
Kumph M. CP 214
Kuparashvili D. CP 30
Kurskov S.Yu. CP 35
Kwela J. CP 180
Kwela J. CP 87
252
Laburthe-Tolra B. CP 53
Laburthe-Tolra B. CP 59
Lagutin B.M. CP 20
Lahaye Th. CP 60
Lammegger R. CP 119
Lammegger R. CP 157
Landragin A. CP 175
Lang F. PR 5
Langkilde-Lauesen M.B. CP 111
Lanzersdorfer J. CP 125
Laporta P. CP 115
Lazur V. CP 36
Lebedev V. PL 6
Lebedev V. CP 181
Lebedev V. CP 182
Lee M.T. CP 33
Lee M.T. CP 141
Lee M.T. CP 215
Leino M. CP 124
Lépine F. CP 208
Leroy C. CP 159
Leroy C. CP 168
Leroy C. CP 79
Leveque T. CP 175
Li W. CP 100
Lindahl A.O. CP 42
Lindroth E. CP 12
Lindroth E. CP 25
Lisdat Chr. CP 58
Litvinov A. CP 158
Liu S. CP 58
Loboda A.V. CP 73
Lohöfer G. CP 207
Lomsadze R. CP 30
Lomsadze B. CP 30
Loreau J. CP 37
Löw R. CP 122
Lundberg H. CP 132
Lundberg H. CP 140
Lundberg H. CP 188
Lundin P. CP 139
Lundin P. CP 140
Machado L.E. CP 33
Mahrov B. CP 107
Mahrov B. CP 160
Maillard Y.P. CP 43
Maiwald M. CP 5
Malcheva G. CP 132
Malinovskaya S.V. CP 127
Manakov N.L. CP 98
Manakov N.L. CP 99
Mangasuli V. CP 65
Mannervik S. CP 139
Manson J.R. CP 212
Mannervik S. CP 140
Maréchal E. CP 53
Maréchal E. CP 59
Marinova K.P. CP 184
Mark M. CP 1
Marler J. CP 111
Marmo S.I. CP 98
Marmo S.I. CP 99
Martinez A. CP 153
Marushka V.I. CP 31
Matisov B. CP 119
Matisov B. CP 158
Matrasulov D.U. CP 78
Matveev A. CP 74
Matveev A. CP 183
Matveeva N.A. CP 118
Maurin I. CP 163
Mauritsson J. PR 10
Mauron O. CP 43
Mayo R. CP 132
Mazets I.E. CP 56
Melezhik V.S. CP 40
Melnikov L.A. CP 93
Merlone A. CP 115
Mestre M. CP 52
Metz J. CP 60
Meyer M. CP 100
Michelin S.E. CP 141
Miculis K. CP 84
Miculis K. CP 106
Miculis K. CP 107
Miculis K. CP 160
Mijailovic M CP 172
Mileti G. CP 119
Minogin V. CP 7
Minogin V. CP 77
Mitchell M.W. CP 113
Mitnik D.M. CP 15
Mitnik D.M CP 9
Mohapatra A.K. CP 167
Mooser A. CP 123
Moroshkin P. PL 6
Moroshkin P. CP 168
Moroshkin P. CP 181
Moroshkin P. CP 182
Motsch M. CP 4
Motsch M. CP 80
Msezane A.Z. CP 134
Mtchedlishvili A. CP 156
Muniz J. CP 153
Musso M. CP 96
Nadeem A. CP 192
Nägerl H.C. CP 1
Nagl J. CP 108
Nagl J. CP 109
Nagl J. CP 125
Nesterov O. CP 145
Nic Chormaic S. CP 7
Nic Chormaic S. CP 77
Niedermayr M. CP 214
Nighat Y. CP 191
Nikoghosyan G. CP 159
Nikolayeva O. CP 150
Nikolayeva O. CP 151
Nilsson H. CP 132
Nilsson H. CP 188
253
Norlin L.O. CP 139
Norlin L.O. CP 140
Nyman R.A. CP 57
Ollagnier A. CP 208
Ortiz M. CP 132
Otajanov D.M. CP 78
Ovcharenko E. CP 41
Ovsiannikov V.D. CP 82
Ovsiannikov V.D. CP 83
Ovsiannikov V.D. CP 91
Ovsiannikov V.D. CP 92
Ozawa A. CP 116
Öztürk I.K. CP 194
Pain J.C. CP 189
Pain J.c. CP 190
Pajek M. CP 43
Pal R. CP 13
Palmeri P. CP 138
Palmeri P, CP 140
Palmeri P. CP 188
Papoyan A. CP 168
Papoyan A. CP 89
Papoyan A. CP 169
Parigi V. CP 113
Parthey C. CP 74
Parthey C. CP 183
Pashayan-Leroy Y.T. CP 79
Pashayan-Leroy Y.T. CP 159
Pashayan-Leroy Y.T. CP 167
Pashayan-Leroy Y.T. CP 168
Pashov A. CP 151
Pawlak M. CP 95
Pazgalev A. CP 156
Pazyuk E.A. CP 150
Pegg D.J. CP 42
Penttila H. CP 184
Perehanets V.V. CP 31
Petrov I.D. CP 20
Petrov I.D. CP 101
Pfanner G. CP 54
Pfau T. CP 60
Pfau T. CP 122
Pichler G. CP 94
Pinegar D. CP 6
Pinegar D. CP 69
Pinkse P.W.H. CP 4
Pinkse P.W.H. CP 80
Piwinski M. CP 48
Pleskacz K. CP 48
Plunien G. CP 22
Plunien G. CP 90
Polasik M CP 43
Poonia S. CP 185
Poonia S. CP 186
Popov Y. CP 34
Porfido N. CP 65
Pottlacher G. CP 206
Pottlacher G. CP 207
Predojevic A. CP 113
Prescimone F. CP 65
Pruvost L. CP 2
Pruvost L. CP 52
Pruvost P. CP 147
Purohit G. CP 38
Quack M. PL 2
Quinet P. CP 132
Quinet P. CP 138
Quinet P. CP 140
Quinet P. CP 187
Quinet P. CP 188
Quint W.H. CP 123
Raboud P.A. CP 43
Radonjic M CP 172
Raitzsch U. CP 122
Rakhimov Kh.Yu CP 19
Rancova O. CP 21
Rancova O. CP 179
Redlin H.. CP 100
Reggami L. CP 105
Rempe G. CP 4
Rempe G. CP 80
Reschab H. CP 206
Resmej F. CP 37
Richardson V. CP 100
Richter M. PR 3
Riehle F. PL 5
Rinkleff R.H. CP 171
Robicheaux F. CP 208
Robyr J.L. CP 155
Rodegheri C. CP 123
Rodionov P. CP 61
Rodriguez K.V. CP 9
Rodriguez K.V. CP 15
Rössl E. CP 96
Royen P. CP 139
Royen P. CP 140
Ruczkowski J. CP 195
Ruczkowski J. CP 199
Ruczkowski J. CP 200
Rudzikas Z. CP 10
Ruiz J. CP 132
Ruzmetov T.A. CP 78
Ryabinina M.V. CP 93
Ryabtsev I.I. CP 51
Ryabtsev I.I. CP 85
Ryabtsev I.I. CP 126
Ryabtsev I.I. CP 160
Ryabtsev I.I. CP 166
Ryazanova O. CP 145
Rzadkiewicz J. CP 43
Saathoff G. CP 116
Sadowski J. CP 67
Saeidian S. CP 40
Safronova M. CP 13
Safronova M. CP 14
Safronova Ul. CP 13
Saidov A.A. CP 78
Saks E. CP 106
Saks E. CP 107
Saks E. CP 160
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Salcedo R. CP 153
Saleem M. CP 76
Saltiel s. CP 162
Saltiel S. CP 163
Samokotin A.Yu. CP 170
Sanches I.P. CP 215
Sansores L.E. CP 153
Sargsyan A. CP 167
Sargsyan A. CP 168
Sarkisyan D. CP 89
Sarkisyan D. CP 167
Sarkisyan D. CP 168
Sarkisyan D. CP 169
Scharf O. CP 71
Schartner K.H. CP 20
Scheel S. CP 112
Schef P. CP 140
Schenk M. CP 4
Schmelcher P. CP 40
Schmidt H. CP 5
Schmidt H. CP 75
Schmidt P.O. CP 213
Schmidt P.O. CP 214
Schmiedmayr J. PL 4
Schmiedmayer J. CP 55
Schmiedmayer J. CP 56
Schmoranzer H. CP 20
Schnizer B. CP 96
Schöbel H. CP 1
Schuessler H. CP 116
Schumm T. CP 56
Schützenhöfer W CP 206
Scrinzi A. PL 11
Scully M.O. PL 7
Seliger M. CP 54
Selsto S. CP 12
Selsto S. CP 25
Semczuk M. CP 116
Semenov R.I. CP 88
Shabaev V.M. CP 22
Shabaev V.M. CP 90
Shafranyosh I.I. CP 31
Shafranyosh I.I. CP 144
Shafranyosh M.I. CP 144
Sharma L. CP 131
Sharma L. CP 177
Sherstov I. CP 58
Shojaei Baghini F. CP 28
Shojaei Baghini F. CP 176
Shpenik O.B. CP 32
Shpenik O.B. CP 211
Siddiqui I. CP 193
Siddiqui I. CP 203
Siddiqui I. CP 204
Skolnik G. CP 94
Slavov D: CP 162
Slavov D. CP 163
Snegurskaya T.A. CP 31
Sokolov A. CP 63
Sokolov A.V. CP 170
Soldán P. CP 149
Sommer Ch. CP 4
Sorokin A.A. PR 3
Sorokin V. CP 61
Sorokin V. CP 63
Sorokin V.N CP 170
Spani Molella L. CP 171
Spanulescu S. CP 97
Srivastava R. CP 131
Srivastava R. CP 177
Staanum P.F. CP 117
Stabkowska K. CP 43
Stachowska E. CP 196
Stania G. CP 8
Stauffer A.D. CP 131
Stauffer A.D. CP 177
Steflekova V. CP 209
Stepanov A. CP 137
Stetsovych V.V. CP 31
Steurer W. CP 212
Stoica C. CP 97
Stolyarov A.V. CP 150
Strambini L. CP 66
Strauss c. PR 5
Strojecki M. CP 114
Sud K.K. CP 38
Sugohara R.T. CP 215
Sujkowski Z. CP 43
Sukharev D.E. CP 130
Sukhorukov V.L. PR 8
Sukhorukov V.L. CP 20
Sukhorukov V.L. CP 101
Sukhoviya M.l CP 144
Sumpf B. CP 5
Svanberg S. CP 132
Svinarenko A.A. CP 17
Sviridov S.A. CP 98
Sviridov S.A. CP 99
Sydoryk I. CP 106
Syty P. CP 39
Szczepkowski J. CP 62
Szczepkowski J. CP 64
Taichenachev A.V. CP 118
Talbi F. CP 148
Tamanis M. CP 150
Tamanis M. CP 151
Tamanis M. CP 164
Tamanis M. CP 194
Tantussi F. CP 65
Tantussi F. CP 66
Tanweer Iqbal S. CP 204
Tanzer R. CP 206
Taskova E. CP 161
Tereschenko E. CP 63
Thoumany P. CP 8
Tiemann E. CP 58
Tiemann E. CP 151
Tino G.M. PL 8
Todorov G. CP 161
Todorov P. CP 162
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Todorov P. CP 163
Tolstikhina I. CP 61
Tomin V.I. CP 146
Tordoff B. CP 184
Torosov B.T. CP 86
Träbert E. CP 136
Tränkle G. CP 5
Tretyakov D.B. CP 51
Tretyakov D.B. CP 85
Tretyakov D.B. CP 126
Tsiskarishvili N.A. CP 30
Tsygankova G.A. CP 88
Tsygankova G.A CP 178
Tumaikin A.M. CP 118
Tungate G. CP 184
Tupitsyn I.I. CP 22
Tupitsyn I.I. CP 90
Uddin Z. CP 193
Udem Th. CP 116
Ulfat I. CP 67
Ullrich J. PR 7
Ulmer S. CP 123
Umarov F.F. CP 29
Urbonas L. CP 8
Vaeck N. CP 37
van Buuren L. CP 4
van Dyck R. CP 6
van Dyck R.S. CP 69
Varoquaux G. CP 57
Vaseva K. CP 162
Vaseva K. CP 163
Vdovic S. CP 94
Vedel F. PR 2
Vernac L. CP 53
Vernac L. CP 59
Vernakelen A. CP 116
Viaris de Lesegno B. CP 2
Viaris de Lesegno B. CP 52
Viaris de Lesegno B. CP 147
Viel A. CP 124
Vitanov N. CP 173
Vitanov N.V. CP 86
Vladimirova Yu.V. CP 170
Volotka A.V. CP 90
von Oppen G. CP 45
von Oppen G. CP 174
Vrakking M CP 208
Vujicic N. CP 94
Walz J. CP 123
Wasowicz T.J. CP 180
Wehr R. CP 115
Weidemüller M. CP 84
Weis A. PL 6
Weis A. CP 154
Weis A. CP 155
Weis A. CP 156
Weis A. CP 168
Weis A. CP 181
Weis A. CP 182
Wendt K. CP 42
Werbowy S. CP 87
Werbowy S. CP 180
Werner L. CP 20
Wester R. PR 1
Wester R. CP 117
Windholz L. CP 119
Windholz L. CP 157
Windholz L. CP 193
Windholz L. CP 196
Windholz L. CP 201
Windholz L. CP 202
Windholz L. CP 203
Windholz L. CP 204
Windholz L. CP 205
Winkler K. PR 5
Witkowski M. CP 62
Witkowski M. CP 64
Wolframm F. CP 113
Wróblewski T. CP 146
Yousif Al-Mula S.Y. CP 102
Yudin V.I. CP 118
Zachorowski J. CP 62
Zadkov V.N CP 170
Zanon T. CP 53
Zanón A. CP 135
Zapryagaev S.A. CP 142
Zapryagaev S.A. CP 143
Zavilopulo A.N. CP 32
Zawada M. CP 62
Zawada M. CP 64
Zemlyanoi S.G. CP 184
Zeppenfeld M. CP 80
Zhechev D. CP 209
Zhu F. CP 116
Zillich R.E. CP 124
Zozulya V. CP 145
Zumsteg C. PR 2
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