# Matt's arXiv selection, Monday 23rd January 2006.

From: Matthew Davis <mdavis_at_physics.uq.edu.au>
Date: Mon, 23 Jan 2006 10:40:31 +1000 (EST)

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Paper: cond-mat/0601289
Date: Fri, 13 Jan 2006 15:52:14 GMT (7kb)

Title: Force on a moving point impurity due to quantum fluctuations in a
Bose-Einstein condensate
Authors: D. C. Roberts
Subj-class: Statistical Mechanics; Other
\\
An analytic expression is derived for a force on a weak point impurity
arising from the scattering of quantum fluctuations in a slow-moving, weakly
interacting, three-dimensional Bose-Einstein condensate at zero temperature.
This force is shown to exist at all flow velocities, including those below
Landau's critical velocity. Furthermore, this force is shown to be directly
proportional to the flow speed.
\\ ( http://arXiv.org/abs/cond-mat/0601289 , 7kb)
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Paper: cond-mat/0508584
replaced with revised version Fri, 13 Jan 2006 20:09:24 GMT (36kb)

Title: Bose-Einstein Condensates in Rotating Lattices
Authors: Rajiv Bhat (1), L. D. Carr (2), M. J. Holland (1) ((1) JILA, National
Institute of Standards and Technology and Department of Physics, University
Comments: 4 pages, 5 figures, Accepted for publication in PRL v2: Replaced
phase winding labels with symmetry eigenstate indices, replaced Gaussian
Ansatz with more general treatment and other minor changes
Subj-class: Other
\\ ( http://arXiv.org/abs/cond-mat/0508584 , 36kb)
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Paper: cond-mat/0508629
replaced with revised version Fri, 13 Jan 2006 09:25:07 GMT (12kb)

Title: Anyonic Excitations in Fast Rotating Bose Gases Revisited
Authors: A. Lakhoua, M. Lassaut, T. Masson, J.C. Wallet
Comments: 5 pages. Improved version to be published in Phys. Rev. A, including
a physical discussion on relevant interactions and scattering regime together
with implication on the nature of statistical interaction
Subj-class: Mesoscopic Systems and Quantum Hall Effect
\\ ( http://arXiv.org/abs/cond-mat/0508629 , 12kb)
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Paper (*cross-listing*): quant-ph/0507167
replaced with revised version Fri, 13 Jan 2006 13:03:33 GMT (91kb)

Title: No approximate complex fermion coherent states
Authors: Tomas Tyc, Brett Hamilton, Barry C. Sanders and William D. Oliver
Subj-class: Quantum Physics; Other
\\ ( http://arXiv.org/abs/quant-ph/0507167 , 91kb)
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Paper: quant-ph/0601085
Date: Thu, 12 Jan 2006 23:34:55 GMT (245kb)

Title: The meaning of group delay in barrier tunneling: A re-examination of
superluminal group velocities
Authors: Herbert G. Winful
\\
We show that the group delay in tunneling is not a traversal time but a
lifetime of stored energy or stored probability escaping through both ends of
the barrier. Because it is a lifetime associated with both forward
(transmitted) and backward (reflected) fluxes, it cannot be used to define a
group velocity for forward transit in cases where a wavepacket is mostly
reflected. For photonic tunneling barriers the group delay is identical to the
dwell time which is also a property of an entire wave function with reflected
and transmitted components. Theoretical predictions and experimental reports of
superluminal group velocities in barrier tunneling are re-interpreted.
\\ ( http://arXiv.org/abs/quant-ph/0601085 , 245kb)
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Paper: quant-ph/0601086
Date: Fri, 13 Jan 2006 00:29:17 GMT (65kb)

Title: What is semiquantum mechanics?
Authors: A.J. Bracken
Comments: Talk presented at IVth International Symposium on Quantum Theory and
Symmetries, Varna, August, 2005. 13 pages, 4 figures
\\
Semiclassical approximations to quantum dynamics are almost as old as quantum
mechanics itself. In the approach pioneered by Wigner, the evolution of his
quasiprobability density function on phase space is expressed as an asymptotic
series in increasing powers of Planck's constant, with the classical
Liouvillean evolution as leading term. Successive semiclassical approximations
to quantum dynamics are defined by successive terms in the series. We consider
a complementary approach, which explores the quantum-clssical interface from
the other direction. Classical dynamics is formulated in Hilbert space, with
the Groenewold quasidensity operator as the image of the Liouville density on
phase space. The evolution of the Groenewold operator is then expressed as an
asymptotic series in increasing powers of Planck's constant. Successive
semiquantum approximations to classical dynamics are defined by successive
terms in this series, with the familiar quantum evolution as leading term.
\\ ( http://arXiv.org/abs/quant-ph/0601086 , 65kb)
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Paper: physics/0601097
Date: Fri, 13 Jan 2006 11:23:24 GMT (467kb)

Title: Atomic collider into dual-isotope magneto-optical trap
Authors: Gregory Surdutovich
Comments: 8 pages, 6 figures. pdf; this paper was reported at ICONO 2005 in
St.-Petersburg
Subj-class: Atomic Physics; Optics
\\
When two of three pairs of the Gaussian laser beams of a traditional MOT are
misaligned in the racetrack configuration the effective coordinate-dependent
vortex force do arise. Then an atom is accelerated by this vortex force until
its velocity not balanced by the damping force. This situation may produce a
stable ring of revolving atoms of a certain radius. Due to the different
frequency and laser beams intensity dependences of the vortex, damping and
trapping forces it is possible to equalize the radii of two orbiting groups of
atoms in two-species or dual-isotope magneto-optical trap and so to arrange a
continuing collider of cooled atoms with the prescribed relative velocity. A
collider setup for atoms of two different types rotating with different angular
velocities along the same ring-like trajectory into MOT of the conventional
six-beam geometry is proposed and designed on example of two rubidium isotopes
Rb85 and Rb87.
\\ ( http://arXiv.org/abs/physics/0601097 , 467kb)
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Paper: cond-mat/0601302
Date: Fri, 13 Jan 2006 21:40:15 GMT (20kb)

Title: Quantum magnetism with multicomponent polar molecules in an optical
lattice
Authors: Ryan Barnett, Dmitry Petrov, Mikhail Lukin, Eugene Demler
Subj-class: Strongly Correlated Electrons
\\
We consider bosonic dipolar molecules in an optical lattice prepared in a
mixture of different rotational states. The 1/r^3 interaction between molecules
for this system is produced by exchanging a quantum of angular momentum between
two molecules. We show that the Mott states of such systems have a large
variety of non-trivial spin orderings including a state with ordering wave
vector that can be changed by tilting the lattice. As the Mott insulating phase
is melted, we also describe several exotic superfluid phases that will occur.
\\ ( http://arXiv.org/abs/cond-mat/0601302 , 20kb)
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Paper: cond-mat/0601307
Date: Mon, 16 Jan 2006 18:54:03 GMT (878kb)

Title: Quantum coherence of Hard-Core-Bosons and Fermions : Extended, Glassy
and Mott Phases
Authors: Ana Maria Rey, Indubala I. Satija and Charles W. Clark
Subj-class: Other
\\
We use Hanbury-Brown-Twiss interferometry (HBTI) to study various quantum
phases of hard core bosons (HCBs) and ideal fermions confined in a
one-dimensional quasi-periodic (QP) potential. For HCBs, the QP potential
induces a cascade of Mott-like band-insulator phases in the extended regime, in
addition to the Mott insulator, Bose glass, and superfluid phases. At critical
filling factors, the appearance of these insulating phases is heralded by a
peak to dip transition in the interferogram, which reflects the fermionic
aspect of HCBs. On the other hand, ideal fermions in the extended phase display
various complexities of incommensurate structures such as devil's staircases
and Arnold tongues. In the localized phase, the HCB and the fermion
correlations are identical except for the sign of the peaks. Finally, we
demonstrate that HBTI provides an effective method to distinguish Mott and
glassy phases.
\\ ( http://arXiv.org/abs/cond-mat/0601307 , 878kb)
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Paper: cond-mat/0601314
Date: Sat, 14 Jan 2006 20:07:43 GMT (447kb)

Title: Density profiles of an imbalance trapped Fermi gas near a Feshbach
resonance
Authors: Theja N. De Silva, Erich J. Mueller
Subj-class: Other
\\
We investigate the density profiles of a partially polarized trapped Fermi
gas in the BCS-BEC crossover region using mean field theory within the local
density approximation. Within this approximation the gas is phase separated
into concentric shells. We describe how the structure of these shells depends
upon the polarization and the interaction strength. Comparison with experiments
yields insight into the possibility of a polarized superfluid phase.
\\ ( http://arXiv.org/abs/cond-mat/0601314 , 447kb)
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Paper: cond-mat/0601321
Date: Sun, 15 Jan 2006 15:14:10 GMT (62kb)

Title: Pairing of a trapped resonantly-interacting fermion mixture with unequal
spin populations
Authors: Masudul Haque and H.T.C. Stoof
Comments: 4 figures, 4+ pages, revtex4
Subj-class: Other; Superconductivity
\\
We consider the phase separation of a trapped atomic mixture of fermions with
unequal spin populations near a Feshbach resonance. In particular, we determine
the density profile of the two spin states and compare with the recent
experiments of Partridge et al. (cond-mat/0511752). Overall we find quite good
agreement. We identify the remaining discrepancies and pose them as open
problems.
\\ ( http://arXiv.org/abs/cond-mat/0601321 , 62kb)
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Paper: cond-mat/0601350
Date: Mon, 16 Jan 2006 15:39:35 GMT (312kb)

Title: Bright solitons in Bose-Fermi mixtures
Authors: Tomasz Karpiuk, Miroslaw Brewczyk, and Kazimierz Rzazewski
Comments: 6 pages, 6 figures, 1 table
Subj-class: Other
\\
We consider the formation of bright solitons in a mixture of Bose and Fermi
degenerate gases confined in a three-dimensional elongated harmonic trap. The
Bose and Fermi atoms are assumed to effectively attract each other whereas
bosonic atoms repel each other. Strong enough attraction between bosonic and
fermionic components can change the character of the interaction within the
bosonic cloud from repulsive to attractive making thus possible the generation
of bright solitons in the mixture. On the other hand, such structures might be
in danger due to the collapse phenomenon existing in attractive gases. We show,
however, that under some conditions (defined by the strength of the Bose-Fermi
components attraction) the structures which neither spread nor collapse can be
generated. For elongated enough traps the formation of solitons is possible
even at the natural'' value of the mutual Bose-Fermi ($^{87}$Rb -$^{40}$K in
our case) scattering length.
\\ ( http://arXiv.org/abs/cond-mat/0601350 , 312kb)
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Paper: cond-mat/0403692
replaced with revised version Sat, 14 Jan 2006 19:23:47 GMT (17kb)

Title: Bell inequalities for random fields
Authors: Peter Morgan
Comments: 18 pages; 1 figure; v3: Better description of the relationship
between classical random fields and quantum fields; better description of
random field models. More extensive references. v2: Abstract and introduction
clarified
Subj-class: Other
\\ ( http://arXiv.org/abs/cond-mat/0403692 , 17kb)
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Paper: cond-mat/0506331
replaced with revised version Sat, 14 Jan 2006 19:16:12 GMT (24kb)

Title: Breathing mode of rapidly rotating Bose-Einstein condensates
Authors: Gentaro Watanabe
Accepted for publication in Phys. Rev. A, one reference added
Report-no: NORDITA-2005-40
Subj-class: Other
\\ ( http://arXiv.org/abs/cond-mat/0506331 , 24kb)
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Paper: cond-mat/0509766
replaced with revised version Mon, 16 Jan 2006 14:41:38 GMT (186kb)

Title: Filled Landau levels in neutral quantum gases
Authors: P. Ohberg, G. Juzeliunas, J. Ruseckas and M. Fleischhauer
Comments: Minor corrections. Phys. Rev. A, 053632 (2005). High resolution
figures can be obtained from the authors
Subj-class: Mesoscopic Systems and Quantum Hall Effect
\\ ( http://arXiv.org/abs/cond-mat/0509766 , 186kb)
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Paper: cond-mat/0509786
replaced with revised version Sat, 14 Jan 2006 23:59:09 GMT (34kb)

Title: General coordinate invariance and conformal invariance in
nonrelativistic physics: Unitary Fermi gas
Authors: D.T. Son and M. Wingate
Report-no: INT-PUB 05-23
Subj-class: Other; Superconductivity; High Energy Physics - Theory; Nuclear
Theory
Journal-ref: Annals Phys. 321 (2006) 197-224
DOI: 10.1016/j.aop.2005.11.001
\\ ( http://arXiv.org/abs/cond-mat/0509786 , 34kb)
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Paper: cond-mat/0511752
replaced with revised version Sat, 14 Jan 2006 00:35:51 GMT (278kb)

Title: Pairing and Phase Separation in a Polarized Fermi Gas
Authors: Guthrie B. Partridge, Wenhui Li, Ramsey I. Kamar, Yean-an Liao,
Randall G. Hulet
Subj-class: Other; Strongly Correlated Electrons; Superconductivity
Journal-ref: Guthrie B. Partridge, Wenhui Li, Ramsey I. Kamar, Yean-an Liao,
and Randall G. Hulet, Science, 23 December 2005 (10.1126/science.1122876)
\\ ( http://arXiv.org/abs/cond-mat/0511752 , 278kb)
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Paper: quant-ph/0601103
Date: Mon, 16 Jan 2006 17:52:01 GMT (81kb)

Title: Optimal estimation of squeezing
Authors: G. Chiribella, G. M. D'Ariano, M. F. Sacchi
Comments: 4 pages, 2 eps figures
\\
We present the optimal estimation of an unknown squeezing transformation of
the radiation field. The optimal estimation is unbiased and is obtained by
properly considering the degeneracy of the squeezing operator. For coherent
input states, the r.m.s. of the estimation scales as $(2\sqrt {\bar n})^{-1}$
versus the average photon number $\bar n$, while it can be enhanced to $(2\bar n)^{-1}$ by using displaced squeezed states.
\\ ( http://arXiv.org/abs/quant-ph/0601103 , 81kb)
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Paper (*cross-listing*): cond-mat/0503187
Date: Tue, 8 Mar 2005 17:19:30 GMT (12kb)

Title: Non-Abelian gauge potentials for ultra-cold atoms with degenerate dark
states
Authors: J. Ruseckas, G. Juzeliunas, P. Oehberg, M. Fleischhauer
Categories: cond-mat.mes-hall
Subj-class: Mesoscopic Systems and Quantum Hall Effect
Journal-ref: Phys. Rev. Lett. 95, 010404 (2005)
DOI: 10.1103/PhysRevLett.95.010404
\\
We show that the adiabatic motion of ultra-cold, multi-level atoms in
spatially varying laser fields can give rise to effective non-Abelian gauge
fields if degenerate adiabatic eigenstates of the atom-laser interaction exist.
A pair of such degenerate dark states emerges e.g. if laser fields couple three
internal states of an atom to a fourth common one under pairwise
two--photon-resonance conditions. For this so-called tripod scheme we derive
general conditions for truly non-Abelian gauge potentials and discuss special
examples. In particular we show that using orthogonal laser beams with orbital
angular momentum an effective magnetic field can be generated that has a
monopole component.
\\ ( http://arXiv.org/abs/cond-mat/0503187 , 12kb)
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Paper: quant-ph/0509038
replaced with revised version Mon, 16 Jan 2006 15:47:03 GMT (258kb)

Title: Stochastic mean-field dynamics for fermions in the weak coupling limit
Authors: Denis Lacroix
Comments: Enlarged version, 10 pages, 2 figures
Subj-class: Quantum Physics; Strongly Correlated Electrons
\\ ( http://arXiv.org/abs/quant-ph/0509038 , 258kb)
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Paper: quant-ph/0512214
replaced with revised version Mon, 16 Jan 2006 07:31:16 GMT (89kb)

Title: Infinite qubit rings with maximal nearest neighbor entanglement: the
Bethe ansatz solution
Authors: U. V. Poulsen, T. Meyer, D. Bruss, M. Lewenstein
Comments: 10 pages, 4 figures; updated references
\\ ( http://arXiv.org/abs/quant-ph/0512214 , 89kb)
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Paper (*cross-listing*): cond-mat/0512481
Date: Mon, 19 Dec 2005 22:08:11 GMT (71kb)

Title: Tunnelling rates for the nonlinear Wannier-Stark problem
Authors: Sandro Wimberger, Peter Schlagheck, and Riccardo Mannella
Subj-class: Other; Atomic Physics; Computational Physics
Journal-ref: J. Phys. B: At. Mol. Opt. Phys. 39 729-740 (2006)
DOI: 10.1088/0953-4075/39/3/024
\\
We present a method to numerically compute accurate tunnelling rates for a
Bose-Einstein condensate which is described by the nonlinear Gross-Pitaevskii
equation. Our method is based on a sophisticated real-time integration of the
complex-scaled Gross-Pitaevskii equation, and it is capable of finding the
stationary eigenvalues for the Wannier-Stark problem. We show that even weak
nonlinearities have significant effects in the vicinity of very sensitive
resonant tunnelling peaks, which occur in the rates as a function of the Stark
field amplitude. The mean-field interaction induces a broadening and a shift of
the peaks, and the latter is explained by analytic perturbation theory.
\\ ( http://arXiv.org/abs/cond-mat/0512481 , 71kb)
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Paper: cond-mat/0505306
replaced with revised version Tue, 17 Jan 2006 19:41:56 GMT (51kb)

Title: Many body exchange effects close to the s-wave Feshbach resonance in
two-component Fermi systems: Is a triplet superfluid possible?
Authors: Sergio Gaudio (1)(2), Jason Jackiewicz (2), Kevin S. Bedell (2) ((1)
Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM,
(2)Department of Physics, Boston College, Chestnut Hill, MA)
Comments: 5 pages, 5 figures,revised text version
Report-no: LAUR - 05-3423
Subj-class: Other
\\ ( http://arXiv.org/abs/cond-mat/0505306 , 51kb)
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Paper: cond-mat/0512134
replaced with revised version Tue, 17 Jan 2006 19:29:07 GMT (51kb)

Title: Acoustic attenuation probe for fermion superfluidity in ultracold atom
gases
Authors: Sergio Gaudio (1)(2), B. Mihaila (2), K. B. Blagoev (2), K. S. Bedell
(1), Eddy Timmermans (2) (1) (Department of Physics, Boston College) (2)
(Theoretical Division, Los Alamos Natl Labs)
Comments: 5 pages, 2 figures. submitted to PRL
Report-no: LAUR-05-3432
Subj-class: Other
\\ ( http://arXiv.org/abs/cond-mat/0512134 , 51kb)
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Paper: cond-mat/0512451
replaced with revised version Mon, 16 Jan 2006 23:33:38 GMT (28kb)

Title: Classification of Light-Induced Desorption of Alkali Atoms in Glass
Cells Used in Atomic Physics Experiments
Authors: Atsushi Hatakeyama, Markus Wilde, Katsuyuki Fukutani
Comments: 6 pages, 1 figure; minor corrections made, published in e-Journal of
Surface Science and Nanotechnology at
http://www.jstage.jst.go.jp/article/ejssnt/4/0/4_63/_article
Subj-class: Other; Atomic Physics
Journal-ref: e-J. Surf. Sci. Nanotech. Vol.4 (2006) 63-68
DOI: 10.1380/ejssnt.2006.63
\\ ( http://arXiv.org/abs/cond-mat/0512451 , 28kb)
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Paper: cond-mat/0601175
replaced with revised version Tue, 17 Jan 2006 15:21:59 GMT (30kb)

Title: Superfluid-Insulator transitions of bosons on Kagome lattice at
non-integer fillings
Authors: K. Sengupta, S. V. Isakov, Yong Baek Kim
Subj-class: Strongly Correlated Electrons; Superconductivity
\\ ( http://arXiv.org/abs/cond-mat/0601175 , 30kb)
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Paper: quant-ph/0601104
Date: Mon, 16 Jan 2006 21:03:08 GMT (183kb)

Title: Nonlinear Interferometry via Fock State Projection
Authors: G. Khoury, H.S. Eisenberg, E.J.S. Fonseca, and D. Bouwmeester
\\
We use a photon-number resolving detector to monitor the photon number
distribution of the output of an interferometer, as a function of phase delay.
As inputs we use coherent states with mean photon number up to seven. The
postselection of a specific Fock (photon-number) state effectively induces
high-order optical non-linearities. Following a scheme by Bentley and Boyd
[S.J. Bentley and R.W. Boyd, Optics Express 12, 5735 (2004)] we explore this
effect to demonstrate interference patterns a factor of five smaller than the
Rayleigh limit.
\\ ( http://arXiv.org/abs/quant-ph/0601104 , 183kb)
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Paper: quant-ph/0601107
Date: Tue, 17 Jan 2006 03:02:00 GMT (8kb)

Title: Many setting Bell's inequalities and Peres's conjecture
Authors: Koji Nagata and Wieslaw Laskowski
\\
We derive $d$-setting Bell inequality for $N$ qubits states ($d\geq 2$). We
investigate violations of the $d$-setting Bell inequality under the assumption
that suitable partial transposes of the density operator are positive. If the
partial transposes with respect to all subsystems are positive, all these Bell
inequalities are satisfied. This feature is independent of the values of $d$.
This is further supporting evidence for a conjecture by Peres that positivity
of partial transposes could lead us to the existence of the local realistic
theory. Further, it turns out that Greenberger-Horne-Zeilinger states violate
maximally all these Bell inequalities.
\\ ( http://arXiv.org/abs/quant-ph/0601107 , 8kb)
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Paper: cond-mat/0601392
Date: Tue, 17 Jan 2006 22:00:03 GMT (533kb)

Title: Noise Thermometry with Two Weakly Coupled Bose-Einstein Condensates
Authors: Rudolf Gati, Boerge Hemmerling, Jonas Foelling, Michael Albiez, Markus
K. Oberthaler
Subj-class: Other
\\
Here we report on the experimental investigation of thermally induced
fluctuations of the relative phase between two Bose-Einstein condensates which
are coupled via tunneling. The experimental control over the coupling strength
and the temperature of the thermal background allows for the quantitative
analysis of the phase fluctuations. Furthermore, we demonstrate the application
of these measurements for thermometry in a regime where standard methods fail.
With this we confirm that the heat capacity of an ideal Bose gas deviates from
that of a classical gas as predicted by the third law of thermodynamics.
\\ ( http://arXiv.org/abs/cond-mat/0601392 , 533kb)
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Paper: cond-mat/0601403
Date: Wed, 18 Jan 2006 10:32:48 GMT (453kb)

Title: Theory of coherent transport by an ultra-cold atomic Fermi gas through
linear arrays of potential wells
Authors: M.R. Bakhtiari, P. Vignolo, M.P. Tosi (SNS Pisa, Italy)
Subj-class: Disordered Systems and Neural Networks; Other
\\
Growing interest is being given to transport of ultra-cold atomic gases
through optical lattices generated by the interference of laser beams. In this
connection we evaluate the phase-coherent transport of a spin-polarized gas of
fermionic atoms along linear structures made from potential wells set in four
alternative types of sequence. These are periodic chains of either identical
wells or pairs of different wells, and chains of pairs of wells arranged in
either a Fibonacci quasi-periodic sequence or a random sequence. The
transmission coefficient of fermionic matter is evaluated in a T-matrix
scattering approach by describing each array through a tight-binding
Hamiltonian and by reducing it to an effective dimer by means of a
decimation/renormalization method. The results are discussed in comparison with
those pertaining to transport by Fermi-surface electrons coupled to an outgoing
lead and by an atomic Bose-Einstein condensate. Main attention is given to (i)
Bloch oscillations and their mapping into alternating-current flow through a
Josephson junction; (ii) interference patterns that arise on period doubling
and their analogy with beam splitting in optical interferometry; (iii)
localization by quasi-periodic disorder inside a Fibonacci-ordered structure of
double wells; and (iv) Anderson localization in a random structure of double
wells.
\\ ( http://arXiv.org/abs/cond-mat/0601403 , 453kb)
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Paper: cond-mat/0601408
Date: Wed, 18 Jan 2006 13:33:40 GMT (501kb)

Title: From a nonlinear string to a weakly interacting Bose gas
Authors: Emilia Witkowska, Mariusz Gajda and Jan Mostowski
Subj-class: Other
\\
We investigate a real scalar field whose dynamics is governed by a nonlinear
wave equation. We show that classical description can be applied to a quantum
system of many interacting bosons provided that some quantum ingredients are
included. An universal action has to be introduced in order to define particle
number. The value of this action should be equal to the Planck constant. This
constrain can be imposed by removing high frequency modes from the dynamics by
introducing a cut-off. We show that the position of the cut-off has to be
carefully adjusted. Finally, we show the proper choice of the cut-off ensures
that all low frequency eigenenmodes which are taken into account are
macroscopically occupied.
\\ ( http://arXiv.org/abs/cond-mat/0601408 , 501kb)
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Paper: cond-mat/0601414
Date: Wed, 18 Jan 2006 15:59:50 GMT (50kb)

Title: Homonuclear ionizing collisions of laser-cooled metastable helium atoms
Authors: R. J. W. Stas, J. M. McNamara, W. Hogervorst and W. Vassen
Comments: 15 pages, 6 figures, submitted to Phys. Rev. A
Subj-class: Other
\\
We present a theoretical and experimental investigation of homonuclear
ionizing collisions of laser-cooled metastable helium atoms, considering both
the fermionic He-3 and bosonic He-4 isotope. The theoretical description
combines quantum threshold behavior, Wigner's spin-conservation rule and
quantum statistical symmetry requirements in a single-channel model,
complementing a more complete close-coupling theory that has been reported for
collisions of metastable He-4 atoms. The model is supported with measurements
(in the absence of light fields) of ionization rates in magneto-optically
trapped samples, that contain about 3*10^8 atoms of a single isotope. The
ionization rates are determined from measurements of trap loss due to
light-assisted collisions combined with comparative measurements of the ion
production rate in the absence and presence of trapping light. Theory and
experiment show good agreement.
\\ ( http://arXiv.org/abs/cond-mat/0601414 , 50kb)
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Paper: cond-mat/0601416
Date: Wed, 18 Jan 2006 17:43:53 GMT (11kb)

Title: Unconventional strongly interacting Bose-Einstein condensates in optical
lattices
Authors: A. B. Kuklov
Comments: 4 revtex pages, no figures
Subj-class: Other
\\
Adding particles to Bose-Mott insulator with the unity filling factor favors
superfluid ground states with non-zero momentum, if the onsite repulsion
exceeds the one-particle band gap. Such non-s-wave condensates, which break
symmetry of the lattice and may also feature the spontaneous time-reversal
symmetry breaking, can be revealed in specific absorption imaging patterns. The
case when fermions are added to the insulator is discussed as well.
\\ ( http://arXiv.org/abs/cond-mat/0601416 , 11kb)
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Paper: cond-mat/0601420
Date: Wed, 18 Jan 2006 19:59:28 GMT (934kb)

Title: Production of cold molecules via magnetically tunable Feshbach
resonances
Authors: Thorsten Koehler, Krzysztof Goral, Paul S. Julienne
Comments: 50 pages, 26 figures, submitted to Reviews of Modern Physics
Subj-class: Other
\\
Magnetically tunable Feshbach resonances were employed to associate cold
diatomic molecules in a series of experiments involving both atomic Bose as
well as two spin component Fermi gases. This review illustrates theoretical
concepts of both the particular nature of the highly excited Feshbach molecules
produced and the techniques for their association from unbound atom pairs.
Coupled channels theory provides the rigorous formulation of the microscopic
physics of Feshbach resonances in cold gases. Concepts of dressed versus bare
energy states, universal properties of Feshbach molecules, as well as the
classification in terms of entrance- and closed-channel dominated resonances
are introduced on the basis of practical two-channel approaches. Their
significance is illustrated for several experimental observations, such as
binding energies and lifetimes with respect to collisional relaxation.
Molecular association and dissociation are discussed in the context of
techniques involving linear magnetic field sweeps in cold Bose and Fermi gases
as well as pulse sequences leading to Ramsey-type interference fringes. Their
descriptions in terms of Landau-Zener, two-level mean field as well as beyond
mean field approaches are reviewed in detail, including the associated ranges
of validity.
\\ ( http://arXiv.org/abs/cond-mat/0601420 , 934kb)
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Paper: cond-mat/0402089
replaced with revised version Wed, 18 Jan 2006 17:42:58 GMT (58kb)

Title: Complex scaling approach to the decay of Bose-Einstein condensates
Authors: Peter Schlagheck and Tobias Paul
Subj-class: Soft Condensed Matter
\\ ( http://arXiv.org/abs/cond-mat/0402089 , 58kb)
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Paper: cond-mat/0411090
replaced with revised version Tue, 17 Jan 2006 23:00:34 GMT (88kb)

Title: Thermodynamics of Interacting Fermions in Atomic Traps
Authors: Qijin Chen, Jelena Stajic, and K. Levin
Comments: Final version -- Published in PRL. 4 figures
Subj-class: Superconductivity; Statistical Mechanics
Journal-ref: Phys. Rev. Lett. 95, 260405 (2005)
DOI: 10.1103/PhysRevLett.95.260405
\\ ( http://arXiv.org/abs/cond-mat/0411090 , 88kb)
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Paper: cond-mat/0502096
replaced with revised version Wed, 18 Jan 2006 10:30:26 GMT (254kb)

Title: Supershell structure in trapped dilute Fermi gases
Authors: Y.Yu, M. Ogren, S. Aberg, S. M. Reimann and M. Brack
Comments: 4 pages, 4 figures; In version 2, references added. The semiclassical
explanation of super-shell structure is refined. Version 3, as appeared in
Phys. Rev. A
Subj-class: Other
Journal-ref: Phys. Rev. A 72, 051602(R) (2005)
\\ ( http://arXiv.org/abs/cond-mat/0502096 , 254kb)
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Paper: cond-mat/0505689
replaced with revised version Tue, 17 Jan 2006 23:25:48 GMT (29kb)

Title: Population of closed-channel molecules in trapped Fermi gases with broad
Feshbach resonances
Authors: Qijin Chen and K. Levin
Comments: 4 pages, 3 figures, published in PRL
Subj-class: Superconductivity
Journal-ref: Phys. Rev. Lett. 95, 260406 (2005)
DOI: 10.1103/PhysRevLett.95.260406
\\ ( http://arXiv.org/abs/cond-mat/0505689 , 29kb)
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Paper: cond-mat/0601432
Date: Thu, 19 Jan 2006 19:21:34 GMT (435kb)

Title: Orbital Bose-Einstein condensation at non-zero momentum
Authors: W. Vincent Liu and Congjun Wu
Comments: 9 pages, 7 figures (with one in Appendix)
Subj-class: Other; Strongly Correlated Electrons
\\
The paradigm of Bose-Einstein condensation has been associated with zero
momentum to which a macroscopic fraction of bosons condense. Here we propose a
new quantum state where p-orbital atoms condense at non-zero momenta, defying
the zero momentum hallmark. Angular momentum simultaneously develops a
transversely staggered orbital current order, reminiscent of orbital
antiferromagnetism or d-density wave in correlated electronic systems. The new
state is predicted for a Bose-Fermi mixture of cold atoms confined in optical
lattices. We suggest that an interspecies Feshbach resonance significantly
reduces the energy gap between s and p bands, and a non-resonant two-boson
correlation further achieves a band reversal--favoring bosons populating the
p-band. The result is a new p-orbital Bose-Hubbard model, which perhaps has far
more implications for surprising quantum collective phenomena than realized
here.
\\ ( http://arXiv.org/abs/cond-mat/0601432 , 435kb)
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Paper: cond-mat/0601437
Date: Thu, 19 Jan 2006 10:49:01 GMT (42kb)

Title: Momentum interferences of a freely expanding Bose-Einstein condensate in
1D due to interatomic interaction change
Authors: A. Ruschhaupt, A. del Campo, and J. G. Muga
Subj-class: Other
\\
A Bose-Einstein condensate may be prepared in a highly elongated harmonic
trap with negligible interatomic interactions using a Feshbach resonance. If a
strong repulsive interatomic interaction is switched on and the axial trap is
removed to let the condensate evolve freely in the axial direction, a time
dependent quantum interference pattern takes place in the short time
(Thomas-Fermi) regime, in which the number of peaks of the momentum
distribution increases one by one, whereas the spatial density barely changes.
\\ ( http://arXiv.org/abs/cond-mat/0601437 , 42kb)
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Paper: cond-mat/0412174
replaced with revised version Thu, 19 Jan 2006 13:37:22 GMT (156kb)

Title: First-principles quantum dynamics in interacting Bose gases I: The
positive P representation
Authors: P. Deuar and P. D. Drummond
Comments: 21 pages, 7 figures, 2 tables, IOP style
Subj-class: Statistical Mechanics
Journal-ref: J. Phys. A: Math. Gen. 39, 1163 (2006)
\\ ( http://arXiv.org/abs/cond-mat/0412174 , 156kb)
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Paper: quant-ph/0507061
replaced with revised version Thu, 19 Jan 2006 11:23:23 GMT (119kb)

Title: Differential atom interferometry beyond the standard quantum limit
Authors: K. Eckert, P. Hyllus, D. Bruss, U.V. Poulsen, M. Lewenstein, C.
Jentsch, T. Mueller, E.M. Rasel, and W. Ertmer
Comments: 10 pages, 5 figures; eq. (3) corrected and other minor changes
Journal-ref: Phys. Rev. A 73, 013814 (2006)
\\ ( http://arXiv.org/abs/quant-ph/0507061 , 119kb)
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Received on Mon Jan 23 2006 - 10:40:31 EST

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