Matt's arXiv selection: week ending 15th June 2007.

From: Matthew Davis <>
Date: Fri, 15 Jun 2007 21:37:00 +1000 (EST)

The following message was sent to the matts_arxiv list by Matthew Davis <>

So I've found myself with some time at Singapore airport on the way back
to Brisbane, so I thought I may as well be constructive... here is an
early arXiv email!

One thing I should point out: something funny happened with the
Wednesday cond-mat mailing. I went back and trawled through the
abstracts on the web, but it is possible I may have missed something.
If I missed your papers, please let me know and I'll put it in next

Another busy week with 31 new abstracts, and 9 replaced.

Date: Fri, 8 Jun 2007 08:13:11 GMT (360kb)

Title: Dipole Oscillations in Bose - Fermi Mixture in the Time-Dependent
   Grosspitaevskii and Vlasov equations
Authors: Tomoyuki Maruyama, George F. Bertsch
Categories: cond-mat.other
Comments: 17 pages text, and 15 figures
   We study the dipole collective oscillations in the bose-fermi mixture using a
dynamical time-dependent approach, which are formulated with the time-dependent
Gross-Pitaevskii equation and the Vlasov equation. We find big difference in
behaviors of fermion oscillation between the time-dependent approach and usual
approaches such as the random-phase approximation and the sum-rule approach.
While the bose gas oscillates monotonously, the fermion oscillation shows a
beat and a damping. When the amplitude is not minimal, the dipole oscillation
of the fermi gas cannot be described with a simple center-of-mass motion.
\\ ( , 360kb)
Date: Fri, 8 Jun 2007 13:30:57 GMT (30kb)

Title: Polarization and angular distribution of the radiation emitted in
   laser-assisted recombination
Authors: Saverio Bivona, Giovanni Bonanno, Riccardo Burlon, Claudio Leone
Categories: cond-mat.other
Comments: 5 pages, 3 figures
   The effect of an intense external linear polarized radiation field on the
angular distributions and polarization states of the photons emitted during the
radiative recombination is investigated. It is predicted, on symmetry grounds,
and corroborated by numerical calculations of approximate recombination rates,
that emission of elliptically polarized photons occurs when the momentum of the
electron beam is not aligned to the direction of the oscillating field.
Moreover, strong modifications to the angular distributions of the emitted
photons are induced by the external radiation field.
\\ ( , 30kb)
Date: Fri, 8 Jun 2007 16:55:06 GMT (155kb)

Title: Single particle spectrum of resonant population imbalanced Fermi gases
Authors: Francesco Fumarola, Erich J. Mueller
Categories: cond-mat.other cond-mat.stat-mech
Comments: 4 pages, 4 figures
   We use a T-matrix approximation to calculate the single particle spectrum of
the normal state of a gas of Fermionic atoms at low temperature.
   In the strongly interacting regime of the polarized gas, we find that the
spectrum is separated in two branches, leading to a double-peaked
radiofrequency spectral feature.
\\ ( , 155kb)
Date: Fri, 8 Jun 2007 18:54:23 GMT (40kb)

Title: Three bodies bind even when two do not: Efimov states and Fano
   resonances in atoms and nuclei
Authors: A. R. P. Rau
Categories: quant-ph
Comments: 2 figures
   Efimov's prediction more than three decades ago that three-body bound states
can exist when the pairwise attractions do not bind or only support weakly
bound states of a pair, has remained unconfirmed till just the past year. This
lecture provides the pedagogical background for recent work on Efimov states in
neutron-rich nuclei done with I. Mazumdar (TIFR) and V. S. Bhasin (Delhi
University), and published in Phys. Rev. Lett. 97, 062503 (2006). Both these
nuclear systems and recent observations of cold cesium atoms provide the first
clear evidence for the existence of Efimov states.
\\ ( , 40kb)
Date: Fri, 8 Jun 2007 12:24:14 GMT (179kb)

Title: A lattice of microtraps for ultracold atoms based on patterned magnetic
Authors: R. Gerritsma, S. Whitlock, T. Fernholz, H. Schlatter, J. A. Luigjes,
   J.-U. Thiele, J. B. Goedkoop and R. J. C. Spreeuw
Categories: physics.atom-ph
Comments: 7 pages, 7 figures
   We have realized a two dimensional permanent magnetic lattice of
Ioffe-Pritchard microtraps for ultracold atoms. The lattice is formed by a
single 300 nm magnetized layer of FePt, patterned using optical lithography.
Our magnetic lattice consists of more than 15000 tightly confining microtraps
with a density of 1250 traps/mm$^2$. Simple analytical approximations for the
magnetic fields produced by the lattice are used to derive relevant trap
parameters. We load ultracold atoms into at least 30 lattice sites at a
distance of approximately 10 $\mu$m from the film surface. The present result
is an important first step towards quantum information processing with neutral
atoms in magnetic lattice potentials.
\\ ( , 179kb)
Date: Fri, 8 Jun 2007 20:50:01 GMT (303kb)

Title: Finite temperature phase diagram of trapped Fermi gases with population
Authors: Wei Zhang and L.-M. Duan
Categories: cond-mat.str-el cond-mat.supr-con
Comments: 9 pages, 7 figures
   We consider a trapped Fermi gas with population imbalance at finite
temperatures and map out the detailed phase diagram across a wide Feshbach
resonance. We take the Larkin-Ovchinnikov-Fulde-Ferrel (LOFF) state into
consideration and minimize the thermodynamical potential to ensure stability.
Under the local density approximation, we conclude that a stable LOFF state is
present only on the BCS side of the Feshbach resonance, but not on the BEC side
or at unitarity. Furthermore, even on the BCS side, a LOFF state is restricted
at low temperatures and in a small region of the trap, which makes a direct
observation of LOFF state a challenging task.
\\ ( , 303kb)
Date: Mon, 11 Jun 2007 18:48:08 GMT (1363kb)

Title: Hyperspherical approach to the four-body problem
Authors: Nirav P. Mehta, Seth T. Rittenhouse, Jose P. D'Incao, Chris H. Greene
Categories: cond-mat.other
Comments: 10 pages, 3 figures. To be published in: Atomic Structure and
   Collision Processes Publisher: Narosa
   The four-particle system is the simplest few-body system containing the
fundamental physics involved in ultracold fermionic gases. We have made recent
efforts to solve the quantum four-body problem in the adiabatic hyperspherical
representation. Our approach yields a set of coupled potential curves that can
in turn be solved for all elastic and inelastic processes. These rates may play
an important role in the lifetime of molecules in ultracold fermi gases. We
believe this will lead to a deeper understanding of ultracold fermi systems and
the physics of the BCS-BEC crossover.
\\ ( , 1363kb)
Date: Sat, 9 Jun 2007 09:26:24 GMT (42kb)

Title: Lattice bosons in quartic confinement
Authors: R. Ramakumar and A. N. Das
Categories: cond-mat.other cond-mat.stat-mech
Comments: 11 pages including figures
   We present a theoretical study of bose condensation of non-interacting bosons
in finite lattices in quartic potentials in one, two, and three dimensions. We
investigate dimensionality effects and quartic potential effects on single
boson density of energy states, condensation temperature, condensate fraction,
and specific heat. The results obtained are compared with corresponding results
for lattice bosons in harmonic traps.
\\ ( , 42kb)
Date: Sat, 9 Jun 2007 17:14:01 GMT (9kb)

Title: Demonstration that the local density approximation for trapped systems
   is exact in the thermodynamic limit
Authors: Nadia Sandoval-Figueroa and V\'{\i}ctor Romero-Roch\'{\i}n
Categories: cond-mat.stat-mech
Comments: Submitted to Physical Review Letters, 10 pages
   We demonstrate that the so-called ``local density approximation'' used to
calculate thermodynamic properties of systems confined by external potentials
is exact in the thermodynamic limit. We prove our result for classical and
quantum systems as well. We point out that this procedure also validates the
introduction of generalized variables in inhomogeneous fluids that replace the
usual volume and pressure, and in terms of which the equation of state of
confined ultracold gases must be expressed.
\\ ( , 9kb)
Date: Mon, 11 Jun 2007 02:14:36 GMT (356kb)

Title: Strong atom-field coupling for Bose-Einstein condensates in an optical
   cavity on a chip
Authors: Yves Colombe, Tilo Steinmetz, Guilhem Dubois, Felix Linke, David
   Hunger, Jakob Reichel
Categories: quant-ph
   An optical cavity enhances the interaction between atoms and light, and the
rate of coherent atom-photon coupling can be made larger than all decoherence
rates of the system. For single atoms, this strong coupling regime of cavity
quantum electrodynamics (cQED) has been the subject of spectacular experimental
advances, and great efforts have been made to control the coupling rate by
trapping and cooling the atom towards the motional ground state, which has been
achieved in one dimension so far. For N atoms, the three-dimensional ground
state of motion is routinely achieved in atomic Bose-Einstein
condensates(BECs), but although first experiments combining BECs and optical
cavities have been reported recently, coupling BECs to strong-coupling cavities
has remained an elusive goal. Here we report such an experiment, which is made
possible by combining a new type of fibre-based cavity with atom chip
technology. This allows single-atom cQED experiments with a simplified setup,
but moreover realizes the new situation of N atoms in a cavity each of which is
identically and strongly coupled to the cavity mode. The BEC can be positioned
deterministically anywhere within the cavity and localized entirely within a
single antinode of the standing-wave cavity field. This gives rise to a
controlled, tunable coupling rate, as we confirm experimentally. We study the
back action of a cavity transmission measurement as a function of the coupling
rate and find no measurable heating for strongly coupled BECs. The spectrum of
the coupled atoms-cavity system, which we map out over a wide range of atom
numbers and cavity-atom detunings, shows vacuum Rabi splittings exceeding 20
GHz, as well as anticrossings. The system is suitable as a light-matter quantum
interface for quantum information.
\\ ( , 356kb)
Date: Mon, 11 Jun 2007 10:15:11 GMT (319kb)

Title: Observation of squeezed light with 10dB quantum noise reduction
Authors: Henning Vahlbruch, Moritz Mehmet, Nico Lastzka, Boris Hage, Simon
   Chelkowski, Alexander Franzen, Stefan Gossler, Karsten Danzmann and Roman
Categories: quant-ph
Comments: 10 pages, 4 figures
   Squeezing of light's quantum noise requires temporal rearranging of photons.
This again corresponds to creation of quantum correlations between individual
photons. Squeezed light is a non-classical manifestation of light with great
potential in high-precision quantum measurements, for example in the detection
of gravitational waves. Equally promising applications have been proposed in
quantum communication. However, after 20 years of intensive research doubts
arose whether strong squeezing can ever be realized as required for eminent
applications. Here we show experimentally that strong squeezing of light's
quantum noise is possible. We reached a benchmark squeezing factor of 10 in
power (10dB). Thorough analysis reveals that even higher squeezing factors will
be feasible in our setup.
\\ ( , 319kb)
Date: Mon, 11 Jun 2007 13:22:48 GMT (17kb)

Title: Supercurrents in an atom-molecule gas in an optical ring lattice
Authors: T. Wang J. Javanainen S. F. Yelin
Categories: quant-ph
Comments: 5 pages, 4 figures, submitted to PRA
   Atom and molecule currents in a Fermi gas in the neighborhood of a Feshbach
resonance are studied in a one-dimensional optical ring lattice by directly
diagonalizing small models. A rotational analogy of flux quantization is used
to show that fraction of the current is carried by particles with twice the
mass of an atom, which suggests pairing and superfluidity.
\\ ( , 17kb)
Date: Mon, 11 Jun 2007 13:40:53 GMT (19kb)

Title: Fast mode of rotating atoms in one-dimensional lattice rings
Authors: T. Wang and S. F. Yelin
Categories: quant-ph
Comments: 4 pages, 5 figures
   We study the rotation of atoms in one-dimensional lattice rings. In
particular, the "fast mode", where the ground state atoms rotate faster than
the stirring rotating the atoms, is studied both analytically and numerically.
The conditions for the transition to the fast mode are found to be very
different from that in continuum rings. We argue that these transition
frequencies remain unchanged for bosonic condensates described in a mean field.
We show that Fermionic interaction and filling factor have a significant effect
on the transition to the fast mode, and Pauli principle may suppress it
\\ ( , 19kb)
Date: Sat, 9 Jun 2007 09:03:50 GMT (19kb)

Title: Reaction Time of a Group of Physics Students
Authors: Charu Saxena, Rini Kaur, P.Arun
Categories: physics.ed-ph
Comments: 10 pages, 4 figures
   The reaction time of a group of students majoring in Physics is reported
here. Strong co-relation between fatigue, reaction time and performance have
been seen and may be useful for academicians and administrators responsible of
working out time-tables, course structures, students counsellings etc.
\\ ( , 19kb)

Date: 12 June 2007

Title: Breakdown of the Thomas Fermi approximation for polarized Fermi gases
Authors: Rajdeep Sensarma, William Schneider, Roberto B. Diener, Mohit Randeria
Categories: physics.ed-ph
Comments: 10 pages, 4 figures
   We use Bogoliubov de-Gennes theory to show that the commonly used
Thomas-Fermi approximation (TFA) can fail in describing polarized unitary gases
in anisotropic harmonic traps. We find a magnetized superfluid region inside
the trap, with order parameter oscillations, even though there is no such
stable bulk phase. This leads to magnetization profiles that deviate from
contours of constant potential energy. We determine how this violation scales
with trap anisotropy and number of particles, and show that we are able to
account for important differences between the MIT and Rice experiments.
\\ ( , 355kb)

arXiv:0706.1741 [ps, pdf, other] :
     Title: Breakdown of the Thomas Fermi approximation for polarized Fermi gases
     Authors: Rajdeep Sensarma, William Schneider, Roberto B. Diener, Mohit
     Comments: 4 pages 3 figures

Date: Tue, 12 Jun 2007 08:29:41 GMT (117kb)

Title: Rectified momentum transport for a kicked Bose-Einstein Condensate
Authors: Mark Sadgrove, Munekazu Horikoshi, Tetsuo Sekimura, Ken'ichi Nakagawa
Categories: quant-ph
Comments: 4 Pages, 4 Figures. Accepted for publication Phys. Rev. Lett. June
   We report the experimental observation of rectified momentum transport for a
Bose-Einstein Condensate kicked at the Talbot time (quantum resonance) by an
optical standing wave. Atoms are initially prepared in a superposition of the 0
and -2*hbar*kl momentum states using an optical pi/2 pulse. By changing the
relative phase of the superposed states, a momentum current in either direction
along the standing wave may be produced. We offer an interpretation based on
matter wave interference, showing that the observed effect is uniquely quantum.
\\ ( , 117kb)
Date: Tue, 12 Jun 2007 12:50:38 GMT (8kb)

Title: Fluctuations of the Casimir-Polder force between an atom and a
   conducting wall
Authors: R. Messina and R. Passante
Categories: quant-ph
Comments: 6 pages
   We consider the quantum fluctuations of the Casimir-Polder force between a
neutral atom and a perfectly conducting wall in the ground state of the system.
In order to obtain the atom-wall force fluctuation we first define an operator
directly associated to the force experienced by the atom considered as a
polarizable body in an electromagnetic field, and we use a time-averaged force
operator in order to avoid ultraviolet divergences appearing in the fluctuation
of the force. This time-averaged force operator takes into account that any
measurement involves a finite time. We also calculate the Casimir-Polder force
fluctuation for an atom between two conducting walls. Experimental
observability of these Casimir-Polder force fluctuations is also discussed, as
well as the dependence of the relative force fluctuation on the duration of the
\\ ( , 8kb)
Date: Mon, 11 Jun 2007 22:07:15 GMT (523kb)

Title: Resonances of the Quantum $\delta$-Kicked Accelerator
Authors: V. Ramareddy, G. Behinaein, I. Talukdar, P. Ahmadi, G. S. Summy
Categories: physics.atom-ph
Comments: 4 pages, 4 figures
   We report the observation of high order resonances of the quantum
$\delta$-kicked accelerator using a BEC kicked by a standing wave of light. The
signature of these resonances is the existence of quantum accelerator modes.
For the first time quantum accelerator modes were seen near 1/4 and 1/3 of the
Talbot time. Using a BEC enabled us to study the detailed structure of the
modes and resonances which are related to the fractional Talbot effect. We
present a general theory for this system and apply it to predict the behavior
of the accelerator modes.
\\ ( , 523kb)
Date: Tue, 12 Jun 2007 05:33:50 GMT (865kb)

Title: Magneto-optical Trapping of Cadmium
Authors: K.-A. Brickman, M.-S. Chang, M. Acton, A. Chew, D. Matsukevich, P. C.
   Haljan, V. S. Bagnato, and C. Monroe
Categories: physics.atom-ph
Comments: 8 pages, 11 figures
   We report the laser-cooling and confinement of Cd atoms in a magneto-optical
trap, and characterize the loading process from the background Cd vapor. The
trapping laser drives the 1S0-1P1 transition at 229 nm in this two-electron
atom and also photoionizes atoms directly from the 1P1 state. This
photoionization overwhelms the other loss mechanisms and allows a direct
measurement of the photoionization cross section, which we measure to be
2(1)x10^(-16)cm^(2) from the 1P1 state. When combined with nearby laser-cooled
and trapped Cd^(+) ions, this apparatus could facilitate studies in ultracold
interactions between atoms and ions.
\\ ( , 865kb)
Date: Tue, 12 Jun 2007 22:24:13 GMT (10kb)

Title: Soluble Models of Strongly Interacting Ultracold Gas Mixtures in Tight
Authors: M.D. Girardeau and A. Minguzzi
Categories: cond-mat.other
Comments: 4 pages, no figures, revtex4
   A generalized Fermi-Bose mapping method is used to determine the exact ground
states of several models of mixtures of strongly interacting ultracold gases in
tight waveguides, which are generalizations of the Tonks-Girardeau (TG) gas (1D
Bose gas with point hard cores) and fermionic Tonks-Girardeau (FTG) gas (1D
spin-aligned Fermi gas with infinitely strong zero-range attractions). Three
are two-component mixtures of TG and/or ideal Fermi gases with TG interactions
between the two components, three are two-component mixtures of FTG and/or
ideal Bose gases with FTG interactions between the two components, and several
more involve some aspects of both TG and FTG interactions. Exact results are
given for density profiles in a harmonic trap and for single-particle density
matrices and momentum distributions.
\\ ( , 10kb)
Date: Wed, 13 Jun 2007 07:39:19 GMT (180kb)

Title: Vortex pump for dilute Bose-Einstein condensates
Authors: Mikko Mottonen, Ville Pietila, Sami M. M. Virtanen
Categories: cond-mat.mes-hall cond-mat.other
Comments: 4 pages, 3 figures
   The formation of vortices by topological phase engineering has been realized
experimentally to create the first two- and four-quantum vortices in dilute
atomic Bose-Einstein condensates [A. E. Leanhardt et al., Phys. Rev. Lett. 89,
190403 (2002)]. We consider a similar system, but in addition to the
Ioffe-Pritchard magnetic trap we employ an additional hexapole field. By
controlling cyclicly the strengths of these magnetic fields, we show that a
fixed amount of vorticity can be added to the condensate in each cycle. In an
adiabatic operation of this vortex pump, the appearance of vortices into the
condensate is interpreted as the accumulation of a local Berry phase. Our
design can be used as an experimentally realizable vortex source for possible
vortex-based applications of dilute Bose-Einstein condensates.
\\ ( , 180kb)
Date: Wed, 13 Jun 2007 09:05:13 GMT (44kb)

Title: Casimir-Lifshitz force out of thermal equilibrium
Authors: Mauro Antezza, Lev P. Pitaevskii, Sandro Stringari, Vitaly B. Svetovoy
Categories: cond-mat.stat-mech cond-mat.other
Comments: 24 pages, 5 figures
   We study the Casimir-Lifshitz interaction out of thermal equilibrium, with
particular attention devoted to the surface-surface and surface-atom
configurations. A systematic investigation of the contributions to the force
coming from the propagating and evanescent components of the electromagnetic
radiation is performed. The large distance behaviors of such interactions is
discussed, and both analytical and numerical results are compared with the
equilibrium ones. A detailed analysis of the crossing between the
surface-surface and the surface-rarefied body, and finally the surface-atom
force is shown, and a complete derivation and discussion of the recently
predicted non-additivity effects and new asymptotic behaviors is presented.
\\ ( , 44kb)
Date: Wed, 13 Jun 2007 09:18:53 GMT (55kb)

Title: Two-particle binding energy of interacting Bose gases
Authors: K. Morawetz M. M{\"a}nnel, M. Schreiber and P. Lipavsk\'y
Categories: cond-mat.other cond-mat.stat-mech
Comments: 4 pages
   The pole of the two-particle T-matrix including the influence of the
surrounding medium for an interacting Bose gas is analyzed. The phase diagram
of the Bose-Einstein condensation (BEC) depending on the temperature, density,
scattering length, and momentum is derived from this pole. The critical
momentum for the occurrence of superfluidity is obtained in this way. As a new
observation a two-particle binding energy is reported intimately connected with
the occurrence of the BEC. It is suggested that this might have cosmological
consequences on the dark energy problem.
\\ ( , 55kb)
Date: Wed, 13 Jun 2007 10:49:01 GMT (305kb)

Title: Stability of coreless vortices in ferromagnetic spinor Bose-Einstein
Authors: V. Pietila, M. Mottonen, and S. M. M. Virtanen
Categories: cond-mat.mes-hall cond-mat.other
Comments: 7 pages, 6 figures
   We study the energetic and dynamic stability of coreless vortices in
nonrotated spin-1 Bose-Einstein condensates, trapped with a three-dimensional
optical potential and a Ioffe-Pritchard field. The stability of stationary
vortex states is investigated by solving the corresponding Bogoliubov
equations. We show that the quasiparticle excitations corresponding to
axisymmetric stationary states can be taken to be eigenstates of angular
momentum in the axial direction. Our results show that coreless vortex states
can occur as local or global minima of the condensate energy or become
energetically or dynamically unstable depending on the parameters of the
Ioffe-Pritchard field. The experimentally most relevant coreless vortex state
containing a doubly quantized vortex in one of the hyperfine spin components
turned out to have very non-trivial stability regions, and especially a
quasiperiodic dynamic instability region which corresponds to splitting of the
doubly quantized vortex.
\\ ( , 305kb)
Date: Wed, 13 Jun 2007 05:04:47 GMT (403kb)

Title: Holographic storage of multiple coherence gratings in a Bose-Einstein
Authors: Yutaka Yoshikawa, Kazuyuki Nakayama, Yoshio Torii, and Takahiro Kuga
Categories: physics.atom-ph
Comments: 5 pages, 4 figures
   We demonstrate superradiant conversion between a two-mode collective atomic
state and a single-mode light field in an elongated cloud of Bose-condensed
atoms. Two off-resonant write beams induce superradiant Raman scattering,
producing two independent coherence gratings with a different wave vector in
the cloud. By applying phase-matched read beams after a controllable delay, the
gratings can be selectively converted into the light field also in a
superradiant way. Due to the large cooperativity parameter and the small
velocity width of the condensate, a high conversion efficiency of $> 70$ % and
a long storage time of $> 120$ $\mu$s were achieved.
\\ ( , 403kb)
Date: Wed, 13 Jun 2007 13:59:02 GMT (341kb)

Title: Avoiding radiation pressure in an optical cavity interacting with
   ultra-cold atoms
Authors: Simone Bux, Gordon Krenz, Sebastian Slama, Claus Zimmermann, Philippe
   W. Courteille
Categories: physics.atom-ph physics.optics
Comments: 6 pages, 7 figures
   The combination of ultra-cold atomic clouds stored in the light field of
optical cavities provides a powerful model system for the development of new
types of laser cooling and for studying cooperative phenomena. These
experiments critically depend on the precise tuning of an incident pump laser
with respect to a cavity resonance. Here, we present a simple and reliable
experimental tuning scheme based on a two-mode laser spectrometer. The scheme
uses a first laser for probing higher-order transversal modes of the cavity
having an intensity minimum near the cavity's optical axis, where the atoms are
confined. In this way the cavity resonance is observed without exposing the
atoms to unwanted radiation pressure. A second laser, which is phase-locked to
the first one and tuned close to a fundamental cavity mode drives the coherent
atom-field dynamics.
\\ ( , 341kb)
Date: Thu, 14 Jun 2007 10:26:14 GMT (62kb)

Title: Nonclassical dynamics of Bose condensates in an optical lattice in the
   superfluid regime
Authors: Roberto Franzosi (Dipartimento di fisica Universita' di Firenze and
Categories: cond-mat.mes-hall cond-mat.other
Comments: 5 pages, 4 figures
Journal-ref: Phys. Rev. A, 75, 053610 (2007)
   A condensate in an optical lattice, prepared in the ground state of the
superfluid regime, is stimulated first by suddenly increasing the optical
lattice amplitude and then, after a waiting time, by abruptly decreasing this
amplitude to its initial value. Thus the system is first taken to the Mott
regime and then back to the initial superfluid regime. We show that, as a
consequence of this nonadiabatic process, the system falls into a configuration
far from equilibrium whose superfluid order parameter is described in terms of
a particular superposition of Glauber coherent states that we derive. We also
show that the classical equations of motion describing the time evolution of
this system are inequivalent to the standard discrete nonlinear Schreodinger
equations. By numerically integrating such equations with several initial
conditions, we show that the system loses coherence, becoming insulating.
\\ ( , 62kb)
Date: Thu, 14 Jun 2007 10:25:49 GMT (445kb)

Title: Elementary Excitations of a Bose-Einstein Condensate in an Effective
   Magnetic Field
Authors: D. R. Murray (1), P. \"Ohberg (2), Dami\'{a} Gomila (3) and Stephen M.
   Barnett (1) ((1) SUPA, University of Strathclyde, Glasgow, UK (2) SUPA,
   Heriot-Watt University, Edinburgh, UK (3) IFISC, CSIC-UIB, Campus Universitat
   Illes Balears, Palma de Mallorca, Spain)
Categories: cond-mat.other
Comments: 8 pages, 4 figures
   We calculate the low energy elementary excitations of a Bose-Einstein
Condensate in an effective magnetic field. The field is created by the
interplay between light beams carrying orbital angular momentum and the trapped
atoms. We examine the role of the homogeneous magnetic field, familiar from
studies of rotating condensates, and also investigate spectra for vector
potentials with a more general radial dependence. We discuss the instabilities
which arise and how these may be manifested.
\\ ( , 445kb)
Date: Thu, 14 Jun 2007 14:43:06 GMT (74kb)

Title: Boson-Fermion pairing in Bose-Fermi mixtures on 1D optical lattices
Authors: X. Barillier-Pertuisel, S. Pittel, L.Pollet, P. Schuck
Categories: cond-mat.other
Comments: submitted to Phys. Rev. A
   Boson-fermion pairing is considered in a discrete environment of bosons and
fully spin-polarized fermions, coupled via an attractive Bose-Fermi Hubbard
Hamiltonian in one dimension. The results of the T-matrix approximation for
particles of equal mass and at double half filling are compared with the
results of exact diagonalization and with Quantum Monte Carlo results.
Satisfactory agreement for most quantities is found. The appearance of a
stable, weak-coupling pairing mode is also confirmed.
\\ ( , 74kb)
Date: Thu, 14 Jun 2007 17:02:52 GMT (81kb)

Title: General Hubbard model for strongly interacting fermions in an optical
   lattice and its phase detection
Authors: L.-M. Duan
Categories: cond-mat.other cond-mat.supr-con
Comments: 5 pages, 4 figures
   Based on consideration of the system symmetry and its Hilbert space, we show
that strongly interacting fermions in an optical lattice or superlattice can be
generically described by a lattice resonance Hamiltonian. The latter can be
mapped to a general Hubbard model with particle assisted tunneling rates. We
investigate the model under population imbalance and show the attractive and
the repulsive models have the same complexity in phase diagram under the
particle-hole mapping. Using this mapping, we propose an experimental method to
detect possible exotic superfluid/magnetic phases for this system.
\\ ( , 81kb)

The replacements:

replaced with revised version Fri, 8 Jun 2007 16:08:33 GMT (94kb)

Title: Dynamics of a quantum phase transition in a ferromagnetic Bose-Einstein
Authors: Bogdan Damski and Wojciech H. Zurek
Categories: cond-mat.other hep-th quant-ph
Comments: 4 pages & figures, significantly improved presentation with respect
   to the first submission
Report-no: LAUR-07-1400
\\ ( , 94kb)
replaced with revised version Fri, 8 Jun 2007 11:40:41 GMT (9kb)

Title: Quasi localization and quasi mobility edge for the light fermionic atoms
   mixed with the heavy ones
Authors: E. Kogan
Categories: cond-mat.dis-nn
Comments: 4 pages, 1 figure, latex
\\ ( , 9kb)
replaced with revised version Mon, 11 Jun 2007 11:32:32 GMT (202kb)

Title: Fast initialization of a high-fidelity quantum register using optical
Authors: B. Vaucher and S. R. Clark and U. Dorner and D. Jaksch
Categories: cond-mat.other quant-ph
Comments: 22 pages, 9 figures, IOP style. Revised version to appear in NJP
\\ ( , 202kb)
replaced with revised version Mon, 11 Jun 2007 01:26:57 GMT (47kb)

Title: Local Density Functional Theory for Superfluid Fermionic Systems: The
   Unitary Gas
Authors: Aurel Bulgac
Categories: cond-mat.supr-con nucl-th
Comments: 4 pages, 3 eps figures + online appendix, significant changes
   including comparison with new ab initio results
\\ ( , 47kb)
replaced with revised version Mon, 11 Jun 2007 16:22:56 GMT (61kb)

Title: Dynamics of one-dimensional Bose liquids: Andreev-like reflection at
   Y-junctions and absence of the Aharonov-Bohm effect
Authors: Akiyuki Tokuno, Masaki Oshikawa, Eugene Demler
Categories: cond-mat.other cond-mat.mes-hall
Comments: 4pages, 3figures, revised version, a few brief summaries added
\\ ( , 61kb)
replaced with revised version Mon, 11 Jun 2007 15:33:06 GMT (799kb)

Title: Optical Devices for Cold Atoms and Bose-Einstein Condensates
Authors: Naceur Gaaloul (PPM, LSAMA), Amine Jaouadi (PPM, LSAMA), Mourad
   Telmini (LSAMA), Laurence Pruvost (LAC), Eric Charron (PPM)
Categories: quant-ph
Comments: Proceedings of the International Spectroscopy Conference ISC-2007,
   Sousse, Tunisia
\\ ( , 799kb)
replaced with revised version Tue, 12 Jun 2007 08:52:03 GMT (66kb)

Title: Casimir-Polder forces: A non-perturbative approach
Authors: Stefan Yoshi Buhmann, Ho Trung Dung, Ludwig Kn\"{o}ll, Dirk-Gunnar
Categories: quant-ph
Comments: 23 pages, 3 figures, additional misprints corrected
Journal-ref: Physical Review A 70 (5), 052117 (2004)
DOI: 10.1103/PhysRevA.70.052117
\\ ( , 66kb)
replaced with revised version Tue, 12 Jun 2007 08:12:34 GMT (11kb)

Title: Microscopic origin of Casimir-Polder forces
Authors: Stefan Yoshi Buhmann, Hassan Safari, Dirk-Gunnar Welsch, and Ho Trung
Categories: quant-ph
Comments: 10 pages, 0 figures
Journal-ref: Open Systems and Information Dynamics 13 (4), 427 (2006)
DOI: 10.1007/s11080-006-9024-0
\\ ( , 11kb)
replaced with revised version Thu, 14 Jun 2007 12:57:21 GMT (55kb)

Title: Two-particle binding energy of interacting Bose gases
Authors: K. Morawetz M. M{\"a}nnel, M. Schreiber and P. Lipavsk\'y
Categories: cond-mat.other astro-ph cond-mat.stat-mech cond-mat.str-el
Comments: 4 pages
\\ ( , 55kb)

Till next time,

Dr M. J. Davis,               Senior Lecturer in Physics
School of Physical Sciences,  email:
University of Queensland,     ph   : +61 7 334 69824
Brisbane, QLD 4072,           fax  : +61 7 336 51242
Matt's arXiv selection: weekly summary of cold-atom papers from
Legal stuff: Unless stated otherwise, this e-mail represents only the
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Received on Fri Jun 15 2007 - 21:37:00 EST

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