# Matt's arXiv selection, Monday 13 February 2006.

From: Matthew Davis <mdavis_at_physics.uq.edu.au>
Date: Mon, 13 Feb 2006 10:51:41 +1000 (EST)

The following message was sent to the matts_arxiv list by Matthew Davis <mdavis_at_physics.uq.edu.au>

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Paper: cond-mat/0602061
Date: Thu, 2 Feb 2006 22:53:14 GMT (363kb)

Title: Quantum turbulence and correlations in Bose-Einstein condensate
collisions
Authors: A. A. Norrie, R. J. Ballagh, C. W. Gardiner, and A. S. Bradley
Subj-class: Other
\\
We investigate numerically simulated collisions between experimentally
realistic Bose-Einstein condensate wavepackets, within a regime where highly
populated scattering haloes are formed. The theoretical basis for this work is
the truncated Wigner method, for which we present a detailed derivation, paying
particular attention to its validity regime for colliding condensates. This
paper is an extension of our previous Letter [A. A. Norrie, R. J. Ballagh, and
C. W. Gardiner, Phys. Rev. Lett. 94, 040401 (2005)] and we investigate both
single-trajectory solutions, which reveal the presence of quantum turbulence in
the scattering halo, and ensembles of trajectories, which we use to calculate
quantum-mechanical correlation functions of the field.
\\ ( http://arXiv.org/abs/cond-mat/0602061 , 363kb)
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Paper: cond-mat/0602062
Date: Thu, 2 Feb 2006 23:26:55 GMT (44kb)

Title: Three-body recombination of ultracold Bose gases using the truncated
Wigner method
Authors: A. A. Norrie, R. J. Ballagh and C. W. Gardiner
Subj-class: Other
\\
We apply the truncated Wigner method to the process of three-body
recombination in ultracold Bose gases. We find that within the validity regime
of the Wigner truncation for two-body scattering, three-body recombination can
be treated using a set of coupled stochastic differential equations that
include diffusion terms, and can be simulated using known numerical methods. As
an example we investigate the behaviour of a simple homogeneous Bose gas.
\\ ( http://arXiv.org/abs/cond-mat/0602062 , 44kb)
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Paper: cond-mat/0602069
Date: Fri, 3 Feb 2006 07:42:01 GMT (60kb)

Title: Evaporation of an atomic beam on a material surface
Authors: Gael Reinaudi (LKB - Lhomond), Thierry Lahaye (LKB - Lhomond), Antoine
Couvert (LKB - Lhomond), Zhaoying Wang (LKB - Lhomond), David
Gu\'{e}ry-Odelin (LKB - Lhomond)
Comments: Submitted to Phys. Rev. A
Proxy: ccsd ccsd-00018475
Subj-class: Other
\\
We report on the implementation of evaporative cooling of a magnetically
guided beam by adsorption on a ceramic surface. We use a transverse magnetic
field to shift locally the beam towards the surface, where atoms are
selectively evaporated. With a 5~mm long ceramic piece, we gain a factor
$1.5\pm0.2$ on the phase space density. Our results are consistent with a 100%
efficiency of this evaporation process. The flexible implementation that we
have demonstrated, combined with the very local action of the evaporation zone,
makes this method particularly suited for the evaporative cooling of a beam.
\\ ( http://arXiv.org/abs/cond-mat/0602069 , 60kb)
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Paper: cond-mat/0602077
Date: Fri, 3 Feb 2006 17:48:14 GMT (37kb)

Title: Entanglement scaling in critical two-dimensional fermionic and bosonic
systems
Authors: Thomas Barthel, Ming-Chiang Chung, Ulrich Schollwoeck
Subj-class: Statistical Mechanics; Strongly Correlated Electrons
\\
We relate the reduced density matrices of quadratic bosonic and fermionic
models to their Green's function matrices in a unified way and calculate the
scaling of bipartite entanglement of finite systems in an infinite universe
exactly. For critical fermionic 2D systems at T=0, we identify two kinds of
scaling: generically, we find a logarithmic correction to the area law with a
prefactor dependence on the chemical potential that confirms earlier
predictions based on the Widom conjecture. If, however, the gap closes in a
zero-dimensional region of momentum space only, we find an area law with a
sublogarithmic correction only. For a critical bosonic 2D array of coupled
oscillators at T=0, our results indicate that entropy follows the area law
without corrections.
\\ ( http://arXiv.org/abs/cond-mat/0602077 , 37kb)
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Paper: cond-mat/0602080
Date: Fri, 3 Feb 2006 14:55:10 GMT (50kb)

Title: Squeezing in the weakly interacting Bose condensate
Authors: Masudul Haque (Utrecht), Andrei E. Ruckenstein (Rutgers)
Subj-class: Statistical Mechanics; Other
\\
We investigate the presence of squeezing in the weakly repulsive uniform Bose
gas, in both the condensate mode and in the nonzero opposite-momenta mode
pairs, using two different variational formulations. We explore U(1) symmetry
breaking and Goldstone's theorem in the context of a squeezed coherent
variational wavefunction, and present the associated Ward identitiy. Squeezing
of the condensate mode is proved to be strictly absent at the mean field
Hartree-Fock-Bogoliubov level. While condensate-mode squeezing is nonzero due
to contributions from beyond mean field, it is shown to have no thermodynamic
effects. The non-condensate pair-mode squeezing is given a physical
interpretation in terms of density-phase variables using a second variational
wavefunction based on a previous number-conserving formulation of the
interacting Bose gas.
\\ ( http://arXiv.org/abs/cond-mat/0602080 , 50kb)
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Paper: cond-mat/0602091
Date: Fri, 3 Feb 2006 20:25:56 GMT (11kb)

Title: Spin 1/2 Fermions in the Unitary Regime at Finite Temperature
Authors: Aurel Bulgac, Joaquin E. Drut, Piotr Magierski
Comments: 6 pages, 2 figures, version for the Proceedings of QMBT13
Subj-class: Statistical Mechanics
\\
We have performed a fully non-perturbative calculation of the thermal
properties of a system of spin 1/2 fermions in 3D in the unitary regime. We
have determined the critical temperature for the superfluid-normal phase
transition. The thermodynamic behavior of this system presents a number of
unexpected features, and we conclude that spin 1/2 fermions in the BCS-BEC
crossover should be classified as a new type of superfluid.
\\ ( http://arXiv.org/abs/cond-mat/0602091 , 11kb)
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Paper: quant-ph/0602033
Date: Thu, 2 Feb 2006 23:45:05 GMT (533kb)

Title: Continuous variable tripartite entanglement and Einstein-Podolsky-Rosen
correlations from triple nonlinearities
Authors: M.K. Olsen, A.S. Bradley, M.D. Reid
\\
We compare theoretically the tripartite entanglement available from the use
of three concurrent $\chi^{(2)}$ nonlinearities and three independent squeezed
states mixed on beamsplitters, using the van Loock-Furusawa inequalities. We
also define three-mode generalisations of the Einstein-Podolsky-Rosen paradox
which are an alternative for demonstrating the inseparability of the density
matrix.
\\ ( http://arXiv.org/abs/quant-ph/0602033 , 533kb)
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Paper: quant-ph/0602048
Date: Fri, 3 Feb 2006 17:13:26 GMT (10kb)

Title: Single-Site Entanglement of Fermions at a Quantum Phase Transition
Authors: Daniel Larsson and Henrik Johannesson
\\
We show that the single-site entanglement of a generic spin-1/2 fermionic
lattice system can be used as a reliable marker of a finite-order quantum phase
transition, given certain provisos. We discuss the information contained in the
single-site entanglement measure, and provide illustrations from the
Mott-Hubbard metal-insulator transitions of the one-dimensional Hubbard model,
and the Hubbard model with long-range hopping.
\\ ( http://arXiv.org/abs/quant-ph/0602048 , 10kb)
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Paper: physics/0509109
replaced with revised version Fri, 3 Feb 2006 03:31:44 GMT (714kb)

Title: Coherent control of ultracold molecule dynamics in a magneto-optical
trap using chirped femtosecond laser pulses
Authors: Benjamin L. Brown, Alexander J. Dicks, Ian A. Walmsley
Comments: 4 pages, 4 figures v2 - slight corrections
Subj-class: Atomic Physics; Chemical Physics
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Paper: cond-mat/0602100
Date: Sat, 4 Feb 2006 09:43:38 GMT (59kb)

Title: Bloch oscillations of strongly interacting Bose atoms
Authors: Andrey R. Kolovsky
Comments: EPL-style, 6 pages, 3 figures
Subj-class: Other
\\
We analyse Bloch oscillations (i.e., oscillations induced by a static force)
of strongly interacting Bose atoms {\em beyond} the hard-core bosons model. It
is shown that residual interactions between the atoms modulate Bloch
oscillations, where the type of modulations depends on the magnitude of the
static force.
\\ ( http://arXiv.org/abs/cond-mat/0602100 , 59kb)
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Paper: cond-mat/0602103
Date: Sat, 4 Feb 2006 16:59:49 GMT (203kb)

Title: A lattice of double wells for manipulating pairs of cold atoms
Authors: J. Sebby-Strabley, M. Anderlini, P. S. Jessen, and J. V. Porto
Comments: 9 pages, 11 figures Accepted for publication in Physical Review A
Subj-class: Other
\\
We describe the design and implementation of a 2D optical lattice of double
wells suitable for isolating and manipulating an array of individual pairs of
atoms in an optical lattice. Atoms in the square lattice can be placed in a
double well with any of their four nearest neighbors. The properties of the
double well (the barrier height and relative energy offset of the paired sites)
can be dynamically controlled. The topology of the lattice is phase stable
against phase noise imparted by vibrational noise on mirrors. We demonstrate
the dynamic control of the lattice by showing the coherent splitting of atoms
from single wells into double wells and observing the resulting double-slit
atom diffraction pattern. This lattice can be used to test controlled neutral
atom motion among lattice sites and should allow for testing controlled
two-qubit gates.
\\ ( http://arXiv.org/abs/cond-mat/0602103 , 203kb)
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Paper: cond-mat/0602108
Date: Sun, 5 Feb 2006 03:08:57 GMT (145kb)

Title: Supersonic optical tunnels for Bose-Einstein condensates
Authors: S. Wuester and B. J. Dabrowska
Subj-class: Other
\\
We propose a new system of energetically stable high-charge ring flows in
Bose-Einstein condensates. It consists of a stack of parallel matter-wave ring
vortices, pinned by an optical vortex laser beam. The quasi one-dimensional
flow through the optical tunnel in the core of the optical vortex can be used
to study the disruption of superfluid behavior above the sound velocity. Our 3D
simulations show the creation of trains of propagating gray solitons and a
temporarily immobile single soliton. The flow past the solitons is supersonic.
We discuss the possibility of using the resulting soliton sonic horizon for the
\\ ( http://arXiv.org/abs/cond-mat/0602108 , 145kb)
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Paper: cond-mat/0602119
Date: Mon, 6 Feb 2006 04:35:02 GMT (42kb)

Title: The effect of thermal fluctuations on spin degrees of freedom in spinor
Bose-Einstein condensate
Authors: W. V. Pogosov, K. Machida
Subj-class: Other
\\
We consider the effect of thermal fluctuations on rotating spinor F=1
condensates in axially-symmetric vortex phases, when all the three hyperfine
states are populated. We show that the relative phase among different
components of the order parameter can fluctuate strongly due to the weakness of
the interaction in the spin channel. These fluctuations can be significant even
at large number of particles condensed and at low temperatures. Fluctuations of
relative phase lead to fluctuations of the local transverse magnetization of
the condensate. We demonstrate that these fluctuations are much more pronounced
for the antiferromagnetic state than for the ferromagnetic one.
\\ ( http://arXiv.org/abs/cond-mat/0602119 , 42kb)
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Paper: cond-mat/0602123
Date: Mon, 6 Feb 2006 10:20:41 GMT (8kb)

Title: Kinetic energy of Bose systems and variation of statistical averages
Authors: V.I. Yukalov
Subj-class: Statistical Mechanics
Journal-ref: Laser Phys. Lett. 3 (2006) 106-111
\\
The problem of defining the average kinetic energy of statistical systems is
addressed. The conditions of applicability for the formula, relating the
average kinetic energy with the mass derivative of the internal energy, are
analysed. It is shown that incorrectly using this formula, outside its region
of validity, leads to paradoxes. An equation is found for a parametric
derivative of the average for an arbitrary operator. A special attention is
paid to the mass derivative of the internal energy, for which a general formula
is derived, without invoking the adiabatic approximation and taking into
account the mass dependence of the potential-energy operator. The results are
illustrated by the case of a low-temperature dilute Bose gas.
\\ ( http://arXiv.org/abs/cond-mat/0602123 , 8kb)
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Paper: cond-mat/0506368
replaced with revised version Mon, 6 Feb 2006 15:23:19 GMT (20kb)

Title: Stability of quasi-two-dimensional Bose-Einstein condensates with
dominant dipole-dipole interactions
Authors: Uwe R. Fischer
Comments: 4 pages of RevTex4, 3 figures; Rapid Communication in Physical Review
A (to be published)
Subj-class: Other
\\ ( http://arXiv.org/abs/cond-mat/0506368 , 20kb)
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Paper: cond-mat/0507506
replaced with revised version Sat, 4 Feb 2006 14:34:32 GMT (469kb)

Title: Collision-Dependent Atom Tunnelling Rate in Bose-Einstein Condensates
Authors: B. R. da Cunha and M. C. de Oliveira
Comments: 4 pages, 2 figures. Replaced with improved version
Subj-class: Other
\\ ( http://arXiv.org/abs/cond-mat/0507506 , 469kb)
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Paper: cond-mat/0602048
replaced with revised version Mon, 6 Feb 2006 15:46:58 GMT (166kb)

Title: Coherent transport of cold atoms in angle-tuned optical lattices
Authors: Roberto Franzosi, Matteo Cristiani, Carlo Sias, Ennio Arimondo
Subj-class: Other
\\ ( http://arXiv.org/abs/cond-mat/0602048 , 166kb)
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Paper: quant-ph/0602054
Date: Sat, 4 Feb 2006 14:55:34 GMT (121kb)

Title: Optimal Conditions for Atomic Homodyne Detection on Bose-Einstein
Condensates
Authors: B. R. da Cunha and M. C. de Oliveira
\\
The dynamics of a two-mode Bose-Einstein condensate trapped in a double-well
potential results approximately in an effective Rabi oscillation regime of
exchange of population between both wells for sufficiently strong overlap
between the modes functions. Facing this system as a temporal atomic beam
splitter we show that this regime is optimal for a nondestructive atom-number
measurement allowing an atomic homodyne detection, thus yielding indirect
relative phase information about one of the two-mode condensates.
\\ ( http://arXiv.org/abs/quant-ph/0602054 , 121kb)
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Paper: physics/0511239
replaced with revised version Mon, 6 Feb 2006 19:11:46 GMT (294kb)

Title: Coupled dynamics of atoms and radiation pressure driven interferometers
Authors: D. Meiser and P. Meystre
corrections
Subj-class: Atomic Physics; Optics; Other
\\ ( http://arXiv.org/abs/physics/0511239 , 294kb)
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Paper: cond-mat/0602157
Date: Mon, 6 Feb 2006 23:02:59 GMT (554kb)

Title: Nonzero orbital angular momentum superfluidity in ultracold Fermi gases
Authors: M. Iskin and C. A. R. S{\'a} de Melo
Comments: 28 pages and 24 figures
Subj-class: Superconductivity; Other
\\
We analyze the evolution of superfluidity for nonzero orbital angular
momentum channels from the Bardeen-Cooper-Schrieffer (BCS) to the Bose-Einstein
condensation (BEC) limit in three dimensions. First, we analyze the low energy
scattering properties of finite range interactions for all possible angular
momentum channels. Second, we discuss ground state ($T = 0$) superfluid
properties including the order parameter, chemical potential, quasiparticle
excitation spectrum, momentum distribution, atomic compressibility, ground
state energy and low energy collective excitations. We show that a quantum
phase transition occurs for nonzero angular momentum pairing, unlike the s-wave
case where the BCS to BEC evolution is just a crossover. Third, we present a
gaussian fluctuation theory near the critical temperature ($T = T_{\rm c}$),
and we analyze the number of bound, scattering and unbound fermions as well as
the chemical potential. Finally, we derive the time-dependent Ginzburg-Landau
functional near $T_{\rm c}$, and compare the Ginzburg-Landau coherence length
with the zero temperature average Cooper pair size.
\\ ( http://arXiv.org/abs/cond-mat/0602157 , 554kb)
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Paper: cond-mat/0602162
Date: Tue, 7 Feb 2006 02:33:07 GMT (373kb)

Title: The stochastic Gross-Pitaevskii equation: III
Authors: A. S. Bradley and C. W. Gardiner
Comments: 25 pages, 2 figures, J. Phys. B. style
Subj-class: Other
\\
A generalised stochastic Gross-Pitaevskii equation describing a partially
condensed trapped Bose gas with rotating thermal component is presented. We
elucidate the manner in which the rotation changes the role of the high energy
cutoff and introduces centrifugal effects in the classical field evolution. The
rotation of the cloud means that Bose-enhanced collision processes occur
preferentially into states with the same angular momentum as the thermal cloud,
thus favouring vortex formation. We use the formalism to obtain a first
principles theory of vortex lattice formation caused by thermodynamic
instability.
\\ ( http://arXiv.org/abs/cond-mat/0602162 , 373kb)
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Paper: cond-mat/0602163
Date: Tue, 7 Feb 2006 15:02:27 GMT (24kb)

Title: A Tonks Giradeau Gas in the Presence of a Local Potential
Authors: Hao Fu, A. G. Rojo
Subj-class: Other
\\
The physics of a Tonks-Giradeau Gas in the presence of a local potential is
studied. In order to evaluate the single particle density matrix (SPDM) of the
many-body ground state, the Wiger-Jordan transformation is used. The
eigenvector with the largest eigenvalue of the SPDM corresponds to the
"Bose-Einstein Condensate"(BEC) State. We find that the "BEC" state density at
the positon of the local potential decreases, as expected, in the case of a
repulsive potential. For an attractive potential, it decreases or increases
depending on the strength of the potential. The superfluidity of this system is
investigated both numerically and perturbatively. An experimental method for
detecting the effect of an impurity in a Tonks-Giradueau gas is discussed.
\\ ( http://arXiv.org/abs/cond-mat/0602163 , 24kb)
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Paper: cond-mat/0602191
Date: Tue, 7 Feb 2006 20:25:03 GMT (640kb)

Title: Stability of trapped fermionic gases with attractive interactions
Authors: Benjamin M. Fregoso and Gordon Baym
Subj-class: Other; Statistical Mechanics
\\
We present a unified overview, from the mean-field to the unitarity regime,
of the stability of a trapped Fermi gas with short range attractive
interactions. Unlike in a system of bosons, a Fermi gas is always stable in
these regimes, no matter how large the particle number. However, when the
interparticle spacing becomes comparable to the range of the interatomic
interactions, instability is not precluded.
\\ ( http://arXiv.org/abs/cond-mat/0602191 , 640kb)
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Paper: cond-mat/0311012
replaced with revised version Tue, 7 Feb 2006 14:00:46 GMT (147kb)

Title: Interaction broadening of Wannier functions and Mott transitions in
atomic BEC
Authors: Jinbin Li, Yue Yu, Artem M. Dudarev, Qian Niu
Comments: A co-author(AMD) added, paper lengthened (7 pages, 8 figures now) to
extend the description of the method and add discussion of its validity
Subj-class: Soft Condensed Matter; Statistical Mechanics
\\ ( http://arXiv.org/abs/cond-mat/0311012 , 147kb)
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Paper: quant-ph/0512061
replaced with revised version Tue, 7 Feb 2006 16:16:23 GMT (178kb)

Title: Highly versatile atomic micro traps generated by multifrequency magnetic
field modulation
Authors: Ph.W. Courteille, B. Deh, J. Fort\'agh, A. G\"unther, S. Kraft, C.
Marzok, S. Slama, and C. Zimmermann
\\ ( http://arXiv.org/abs/quant-ph/0512061 , 178kb)
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Paper: cond-mat/0602201
Date: Wed, 8 Feb 2006 09:26:39 GMT (29kb)

Title: Strong coupling theory for the superfluidity of Bose-Fermi mixtures
Authors: Daw-Wei Wang
Comments: 5 pages and 3 figures
Subj-class: Other; Superconductivity
\\
We develop the strong coupling theory for the superfluidity of fermion s-wave
pairing state in a Bose-Fermi mixture. Dynamical screening, self-energy
renormalization, and pairing gap function are included self-consistently in the
regime where the phonon velocity is smaller than the Fermi velocity. Analytical
form for the transition temperature ($T_c$) is derived within reasonable
approximations. In typical $^{40}$K-$^{87}$Rb mixtures, the obtained $T_c$ is
several times larger than that in the weak coupling theory and can be as high
as several percents of Fermi temperature.
\\ ( http://arXiv.org/abs/cond-mat/0602201 , 29kb)
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Paper: cond-mat/0602210
Date: Wed, 8 Feb 2006 16:41:02 GMT (350kb)

Title: RF Controllable Ioffe-Pritchard Trap
Authors: G.A. Kouzaev, K.J. Sand
Subj-class: Other
\\
An Ioffe-Pritchard trap for cold dressed atoms is studied by analytical and
numerical simulations. The effective potential in this trap is formed by the
static magnetic and radio-frequency fields, and the minimums are formed around
the current bars. The depth of the minimums and the overall topology of the
effective potential are controlled electronically. The studied regime of the
Ioffe-Pritchard trap is of interest for high-sensitive cold atom
interferometers.
\\ ( http://arXiv.org/abs/cond-mat/0602210 , 350kb)
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Paper: cond-mat/0506142
replaced with revised version Tue, 7 Feb 2006 23:42:12 GMT (750kb)

Title: A large magnetic storage ring for Bose-Einstein condensates
Authors: A. S. Arnold, C. S. Garvie, E. Riis
Subj-class: Other
\\ ( http://arXiv.org/abs/cond-mat/0506142 , 750kb)
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Paper: cond-mat/0512294
replaced with revised version Wed, 8 Feb 2006 08:14:23 GMT (21kb)

Title: Goldstone Theorem, Hugenholtz-Pines Theorem and Ward-Takahashi Relation
in Finite Volume Bose-Einstein Condensed Gases
Authors: Hiroaki Enomoto, Masahiko Okumura and Yoshiya Yamanaka
Comments: Accepted for publication in Ann. Phys., 33pages
Subj-class: Strongly Correlated Electrons
\\ ( http://arXiv.org/abs/cond-mat/0512294 , 21kb)
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Paper: cond-mat/0509766
Date: Thu, 29 Sep 2005 12:01:07 GMT (186kb)
Date (revised v2): 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
\\
We consider the signatures of the Integer Quantum Hall Effect in a degenerate
gas of electrically neutral atomic fermions. An effective magnetic field is
achieved by applying two incident light beams with a high orbital angular
momentum. We show how states corresponding to completely filled Landau levels
are obtained and discuss various possibilities to measure the incompressible
nature of the trapped two-dimensional gas
\\ ( http://arXiv.org/abs/cond-mat/0509766 , 186kb)
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Paper: quant-ph/0510173
replaced with revised version Wed, 8 Feb 2006 19:31:59 GMT (192kb)

Title: Unconditional two-mode squeezing of separated atomic ensembles
Authors: A.S. Parkins, E. Solano, J.I. Cirac
Journal-ref: Phys. Rev. Lett. 96, 053602 (2006)
\\ ( http://arXiv.org/abs/quant-ph/0510173 , 192kb)
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Paper: cond-mat/0602224
Date: Thu, 9 Feb 2006 00:44:34 GMT (61kb)

Title: Critical Temperature and Thermodynamics of Attractive Fermions at
Unitarity
Authors: Evgeni Burovski, Nikolay Prokof'ev, Boris Svistunov, and Matthias
Troyer
Subj-class: Statistical Mechanics; Superconductivity
\\
The unitarity regime of the BCS-BEC crossover can be realized by diluting a
system of two-component lattice fermions with an on-site attractive
interaction. We perform a systematic-error-free finite-temperature simulations
of this system by diagrammatic determinant Monte Carlo. The critical
temperature in units of Fermi energy is found to be T_c / E_F = 0.152(7). We
also report the behavior of the thermodynamic functions, and discuss the issues
of thermometry of ultracold Fermi gases.
\\ ( http://arXiv.org/abs/cond-mat/0602224 , 61kb)
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Paper: cond-mat/0602240
Date: Thu, 9 Feb 2006 19:33:12 GMT (153kb)

Title: Bragg spectroscopy of trapped one dimensional strongly interacting
bosons in optical lattices: Probing the cake-structure
Authors: Guido Pupillo, Ana Maria Rey and G. G. Batrouni
Subj-class: Other
\\
We study Bragg spectroscopy of strongly interacting one dimensional bosons
calculate the dynamic structure factor by using Monte Carlo simulations for the
Bose-Hubbard Hamiltonian, exact diagonalizations and the results of a recently
introduced effective fermionization (EF) model. We find that, due to the
system's inhomogeneity, the excitation spectrum exhibits a multi-branched
structure, whose origin is related to the presence of superfluid regions with
different densities in the atomic distribution. We thus suggest that Bragg
spectroscopy in the linear regime can be used as an experimental tool to unveil
the shell structure of alternating Mott insulator and superfluid phases
characteristic of trapped bosons.
\\ ( http://arXiv.org/abs/cond-mat/0602240 , 153kb)
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Paper: quant-ph/0602081
Date: Wed, 8 Feb 2006 23:26:28 GMT (54kb)

Title: Diffusion Resonances in the atom optics kicked rotor: Experimental
values for small kick numbers
Authors: S.A. Wayper, W. Simpson and M.D. Hoogerland
\\
We experimentally verify the analytical expressions that exist for the
diffusion rate in the quantum delta kicked rotor system for small numbers of
kicks. We show development of diffusion resonances from two to five kicks, and
of multiple resonances for high kick strengths. Furthermore, we show that, in
contrast to classical predictions, the results are purely periodic in the kick
period, and reproduce the predicted quantum- and diffusion resonances.
\\ ( http://arXiv.org/abs/quant-ph/0602081 , 54kb)
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Paper: physics/0602059
Date: Thu, 9 Feb 2006 03:16:27 GMT (117kb)

Title: High resolution atomic coherent control via spectral phase manipulation
of an optical frequency comb
Authors: Matthew C. Stowe, Flavio C. Cruz, and Jun Ye
Subj-class: Atomic Physics; Optics
\\
We demonstrate high resolution coherent control of cold atomic Rubidium
utilizing spectral phase manipulation of a femtosecond optical frequency comb.
Transient coherent accumulation is directly manifested by the enhancement of
signal amplitude and spectral resolution via the pulse number. The combination
of frequency comb technology and spectral phase manipulation enables coherent
control techniques to enter a new regime with natural linewidth resolutions.
\\ ( http://arXiv.org/abs/physics/0602059 , 117kb)
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--
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Dr M. J. Davis,               Senior Lecturer in Physics
School of Physical Sciences,  email: mdavis_at_physics.uq.edu.au
University of Queensland,     ph   : +61 7 334 69824
Brisbane, QLD 4072,           fax  : +61 7 336 51242
Australia.                    http://www.physics.uq.edu.au/people/mdavis/
-------------------------------------------------------------------------

Received on Mon Feb 13 2006 - 10:51:41 EST

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