Matt's arXiv selection, Monday 30 January 2006.

From: Matthew Davis <>
Date: Mon, 30 Jan 2006 14:05:44 +1000 (EST)

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

Hi everyone,

Matt's arXiv selection now has a webpage where you will find an archive of
the postings I have made, as well as a short background and instructions
on how to sign up:

If you can pass this around your friends in the field it would be much


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
Paper: cond-mat/0601461
Date: Fri, 20 Jan 2006 02:04:20 GMT   (43kb)
Title: Pairing Symmetry in the Anisotropic Fermi Superfluid under p-wave
   Feshbach Resonance
Authors: Chi-Ho Cheng and Sung-Kit Yip
Comments: 12 pages, 7 figures
Subj-class: Other; Superconductivity
   The anisotropic Fermi superfluid of ultra-cold Fermi atoms under the p-wave
Feshbach resonance is studied theoretically. The pairing symmetry of the ground
state is determined by the strength of the atom-atom magnetic dipole
interaction. It is $k_z$ for a strong dipole interaction; while it becomes $k_z
- i \beta k_y$, up to a rotation about z, for a weak one (Here $\beta$ < 1 is a
numerical coefficient). By changing the external magnetic field or the atomic
gas density, a phase transition between these two states can be driven. We
discuss how the pairing symmetry of the ground state can be determined in the
time-of-flight experiments.
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Paper: cond-mat/0509154
replaced with revised version Fri, 20 Jan 2006 19:14:33 GMT   (237kb)
Title: Quasi-condensate growth on an atom chip
Authors: N.P. Proukakis, J. Schmiedmayer and H.T.C. Stoof
Comments: Detailed Discussion (11 Pages, 7 Fig), Classification of Accessible
   Regimes, Description of Experimental Techniques
Subj-class: Statistical Mechanics
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Paper (*cross-listing*): math-ph/0509060
replaced with revised version Thu, 19 Jan 2006 22:17:28 GMT   (29kb)
Title: Mott transition in lattice boson models
Authors: Roberto Fernandez, Juerg Froehlich, Daniel Ueltschi
Comments: 20 pages
Subj-class: Mathematical Physics; Statistical Mechanics
MSC-class: 82B10, 82B20, 82B26
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Paper: quant-ph/0601137
Date: Fri, 20 Jan 2006 10:15:12 GMT   (441kb)
Title: Theoretical study of a cold atom beam splitter
Authors: Naceur Gaaloul (LPM, LSAMA), Annick Suzor-Weiner (LPM), Laurence
   Pruvost (LAC), Mourad Telmini (LSAMA), Eric Charron (LPM)
Proxy: ccsd ccsd-00017414
   A theoretical model is presented for the study of the dynamics of a cold
atomic cloud falling in the gravity field in the presence of two crossing
dipole guides. The cloud is splitted between the two branches of the guide, and
we compare experimental measurements of the splitting efficiency with
semi-classical simulations. We then explore the possibilities of optimization
of this beam splitter. Our numerical study also gives access to detailed
informations, such as the atom temperature after the splitting. It finally sets
the foundation for a study of the coherence properties of the guided atoms.
\\ ( ,  441kb)
Paper: cond-mat/0601496
Date: Mon, 23 Jan 2006 12:14:53 GMT   (365kb)
Title: Phase separation of two species of fermionic atoms in one-dimensional
   optical lattice
Authors: Shi-Jian Gu, Rui Fan, and Hai-Qing Lin
Comments: 5 pages, 5 figures
Subj-class: Strongly Correlated Electrons
   Motivated by recent development in cold-atomic systems, we study the
ground-state phase diagram of two species of fermionic atoms in one-dimensional
optical lattice, as described by an asymmetric Hubbard model. The quantum phase
transition from density wave to phase separation is investigated by studying
both the corresponding charge order parameter and quantum entanglement. A
rigorous prove, that even for the case of a single hole doping, the density
wave is unstable to the phase separation in the infinite $U$ limit, is given.
Therefore, our results are quite instructive for both on-going experiments on
strongly correlated cold-atomic systems and traditional heavy fermion systems.
\\ ( ,  365kb)
Paper: cond-mat/0601500
Date: Sun, 22 Jan 2006 22:16:06 GMT   (17kb)
Title: Thermodynamically activated vortex-dipole formation in a two-dimensional
   Bose-Einstein condensate
Authors: Daniel Schumayer and David A. W. Hutchinson
Comments: 5 pages, 3 figures
Subj-class: Statistical Mechanics
   Three distinct types of behaviour have recently been identified in the
two-dimensional trapped bosonic gas, namely Bose-Einstein condensate,
Berezinskii-Kosterlitz-Thouless-type (BKT) superfluid and normal gas phases in
order of increasing temperature. In the BKT phase above a critical temperature
$T_{\mathrm{c}}$, the system favours the formation of vortex-antivortex pairs,
since the free energy is lowered by this topological defect.
   We calculate how the minima of free energy vary as a function of the distance
between the vortex-antivortex excitation and the condensate centre for various
particle numbers. We also examine the formation of the minima in the free
energy as a function of temperature to gain insight into the thermodynamic
stability of these phases. Our results qualitatively agree with the findings of
classical field simulations.
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Paper: cond-mat/0601512
Date: Mon, 23 Jan 2006 11:47:39 GMT   (16kb)
Title: Optimal trap shape for a Bose gas with attractive interactions
Authors: V.I. Yukalov and E.P. Yukalova
Comments: Latex file, 21 pages
Subj-class: Mesoscopic Systems and Quantum Hall Effect; Statistical Mechanics
Journal-ref: Phys. Rev. A 72 (2005) 063611-10
   Dilute Bose gas with attractive interactions is considered at zero
temperature, when practically all atoms are in Bose-Einstein condensate. The
problem is addressed aiming at answering the question: What is the optimal trap
shape allowing for the condensation of the maximal number of atoms with
negative scattering lengths? Simple and accurate analytical formulas are
derived allowing for an easy analysis of the optimal trap shapes. These
analytical formulas are the main result of the paper.
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Paper: cond-mat/0407075
replaced with revised version Mon, 23 Jan 2006 13:51:31 GMT   (32kb)
Title: Effects of finite temperature on the Mott insulator state
Authors: Guido Pupillo, Carl J. Williams and Nikolay V. Prokof'ev
Comments: 6 pages, 5 figures; Final version, published in PRA
Subj-class: Other; Quantum Physics
Journal-ref: Phys. Rev. A 73, 013408 (2006)
\\ ( ,  32kb)
Paper: cond-mat/0511341
replaced with revised version Mon, 23 Jan 2006 09:47:24 GMT   (20kb)
Title: Surface-atom force out of thermal equilibrium and its effect on
   ultra-cold atoms
Authors: Mauro Antezza
Comments: Submitted to JPA Special Issue QFEXT'05
Subj-class: Statistical Mechanics; Soft Condensed Matter; Atomic Physics
\\ ( ,  20kb)
Paper: cond-mat/0601140
replaced with revised version Sat, 21 Jan 2006 16:18:39 GMT   (7kb)
Title: Relaxation of the molecular state in atomic Fermi gases near a Feshbach
Authors: V. S. Babichenko
Comments: RevTex4, 4 pages, corrected typos
Subj-class: Other
\\ ( ,  7kb)
Paper: cond-mat/0601416
replaced with revised version Sun, 22 Jan 2006 17:32:17 GMT   (11kb)
Title: Unconventional strongly interacting Bose-Einstein condensates in optical
Authors: A. B. Kuklov
Comments: Corrected and significantly revised version. Discussion of how
   Feynman's argument for nodeless ground states of bosons changes in the
   presence of the non-s-wave Feschbach resonance is added
Subj-class: Other
\\ ( ,  11kb)
Paper: physics/0601073
replaced with revised version Mon, 23 Jan 2006 12:27:31 GMT   (70kb)
Title: Properties of quasi-one-dimensional molecules with Feshbach resonance
Authors: V. A. Yurovsky (Tel Aviv University)
Comments: 7 pages, 5 figures
Subj-class: Atomic Physics; Soft Condensed Matter
\\ ( ,  70kb)
Paper: quant-ph/0601153
Date: Mon, 23 Jan 2006 09:54:39 GMT   (477kb)
Title: Detuned Electromagnetically Induced Transparency in an $N$-type Atom
Authors: Bin Luo and Hong Guo
Comments: 5 pages, 5 figures
Report-no: CREAM/MS-2006-PRL-LG
   The electromagnetically induced transparency (EIT) in an $N$ configuration is
studied under both resonant and off-resonant conditions. In a certain
off-resonant condition the dark state of the four-level system, which is almost
the same as the resonant dark state in $\Lambda$ configuration, is rebuilt. The
actual system with damping is also examined, both numerically and analytically.
Based on the double dark states with frequency shifts some new potential
applications, such as multi-pulse storage, can be hopefully realized.
\\ ( ,  477kb)
Paper: quant-ph/0601154
Date: Mon, 23 Jan 2006 11:24:40 GMT   (75kb)
Title: Simultaneous optical trapping and detection of atoms by microdisk
Authors: Michael Rosenblit, Yonathan Japha, Peter Horak, Ron Folman
Comments: 13 pages, 16 figures
   We propose a scheme for simultaneously trapping and detecting single atoms
near the surface of a substrate using whispering gallery modes of a microdisk
resonator. For efficient atom-mode coupling the atom should be placed within
approximately 150 nm from the disk. We show that a combination of red and blue
detuned modes can form an optical trap at such distances while the back-action
of the atom on the field modes can simultaneously be used for atom detection.
We investigate these trapping potentials including van-der-Waals and
Casimir-Polder forces and discuss corresponding atom detection efficiencies,
depending on a variety of system parameters. Finally, we analyze the
feasibility of non-destructive detection.
\\ ( ,  75kb)
Paper: cond-mat/0601539
Date: Tue, 24 Jan 2006 11:27:36 GMT   (473kb)
Title: Vortex structure in spinor F=2 Bose-Einstein condensates
Authors: W. V. Pogosov, R. Kawate, T. Mizushima, K. Machida
Comments: 6 pages, 3 figures
Subj-class: Other
Journal-ref: Phys. Rev. A 72, 063605 (2005)
   Extended Gross-Pitaevskii equations for the rotating F=2 condensate in a
harmonic trap are solved both numerically and variationally using trial
functions for each component of the wave function. Axially-symmetric vortex
solutions are analyzed and energies of polar and cyclic states are calculated.
The equilibrium transitions between different phases with changing of the
magnetization are studied. We show that at high magnetization the ground state
of the system is determined by interaction in "density" channel, and at low
magnetization spin interactions play a dominant role. Although there are five
hyperfine states, all the particles are always condensed in one, two or three
states. Two novel types of vortex structures are also discussed.
\\ ( ,  473kb)
Paper: cond-mat/0601542
Date: Tue, 24 Jan 2006 12:27:03 GMT   (51kb)
Title: A two-channel R-matrix analysis of magnetic field induced Feshbach
Authors: Nicolai Nygaard, Barry I. Schneider and Paul S. Julienne
Comments: 11 pages, 6 figures. For additional information see
Subj-class: Other
   A Feshbach resonance arises in cold atom scattering due to the complex
interplay between several coupled channels. However, the essential physics of
the resonance may be encapsulated in a simplified model consisting of just two
coupled channels. In this paper we describe in detail how such an effective
Feshbach model can be constructed from knowledge of a few key parameters,
characterizing the atomic Born-Oppenheimer potentials and the low energy
scattering near the resonance. These parameters may be obtained either from
experiment or full coupled channels calculations. Using R-matrix theory we
analyze the bound state spectrum and the scattering properties of the
two-channel model, and find it to be in good agreement with exact calculations.
\\ ( ,  51kb)
Paper: cond-mat/0601550
Date: Tue, 24 Jan 2006 16:19:09 GMT   (35kb)
Title: Parafermionic states in rotating Bose-Einstein condensates
Authors: N. Regnault, Th. Jolicoeur
Comments: 23 pages, 10 figures
Subj-class: Mesoscopic Systems and Quantum Hall Effect
   We investigate possible parafermionic states in rapidly rotating ultracold
bosonic atomic gases at lowest Landau level filling factor nu=k/2. We study how
the system size and interactions act upon the overlap between the true ground
state and a candidate Read-Rezayi state. We also consider the quasihole states
which are expected to display non-Abelian statistics. We numerically evaluate
the degeneracy of these states and show agreement with a formula given by E.
Ardonne. We compute the overlaps between low-lying exact eigenstates and
quasihole candidate wavefunctions. We discuss the validity of the parafermion
description as a function of the filling factor.
\\ ( ,  35kb)
Paper: cond-mat/0509211
replaced with revised version Tue, 24 Jan 2006 10:11:20 GMT   (303kb)
Title: Molecules of Fermionic Atoms in an Optical Lattice
Authors: Thilo St\"oferle, Henning Moritz, Kenneth G\"unter, Michael K\"ohl,
   Tilman Esslinger
Comments: 4 pages
Subj-class: Strongly Correlated Electrons
Journal-ref: Phys. Rev. Lett. 96, 030401 (2006)
DOI: 10.1103/PhysRevLett.96.030401
\\ ( ,  303kb)
Paper: cond-mat/0601314
replaced with revised version Tue, 24 Jan 2006 18:59:12 GMT   (447kb)
Title: Density profiles of an imbalance trapped Fermi gas near a Feshbach
Authors: Theja N. De Silva, Erich J. Mueller
Comments: 4 pages, 5 Figures
Subj-class: Other
\\ ( ,  447kb)
Paper: quant-ph/0601163
Date: Tue, 24 Jan 2006 14:36:07 GMT   (561kb)
Title: Trapping atoms on a transparent permanent-magnet atom chip
Authors: A. Shevchenko, M. Heilio, T. Lindvall, A. Jaakkola, I. Tittonen, M.
   Kaivola, T. Pfau
Comments: 5 pages
   We describe experiments on trapping of atoms in microscopic magneto-optical
traps on an optically transparent permanent-magnet atom chip. The chip is made
of magnetically hard ferrite-garnet material deposited on a dielectric
substrate. The confining magnetic fields are produced by miniature magnetized
patterns recorded in the film by magneto-optical techniques. We trap Rb atoms
on these structures by applying three crossed pairs of counter-propagating
laser beams in the conventional magneto-optical trapping (MOT) geometry. We
demonstrate the flexibility of the concept in creation and in-situ modification
of the trapping geometries through several experiments.
\\ ( ,  561kb)
Paper: cond-mat/0510214
replaced with revised version Tue, 24 Jan 2006 21:34:11 GMT   (21kb)
Title: Worm Algorithm for Continuous-space Path Integral Monte Carlo
Authors: M. Boninsegni, N. Prokof'ev and B. Svistunov
Comments: Accepted for publication in Phys. Rev. Lett
Subj-class: Statistical Mechanics
\\ ( ,  21kb)
Paper: quant-ph/0601170
Date: Wed, 25 Jan 2006 14:15:17 GMT   (307kb)
Title: Decomposing a pulsed optical parametric amplifier into independent
Authors: A. I. Lvovsky, W. Wasilewski, and K. Banaszek
Comments: 12 pages, 5 figures, REVTeX. Submitted to the proceedings of the
   Conference Quantum Optics VI, published as a Special Issue of Jounal of
   Modern Optics
   We discuss the concept of characteristic squeezing modes applied to a
travelling-wave optical parametric amplifier pumped by an ultrashort pulse. The
characteristic modes undergo decoupled single-mode squeezing transformations,
and therefore they form a useful basis to describe the evolution of the entire
multimode system. This provides an elegant and intuitive picture of quantum
statistical properties of parametric fluorescence. We analyse the efficiency of
detecting quadrature squeezing, and present results of numerical calculations
for a realistic nonlinear medium.
\\ ( ,  307kb)
Paper: quant-ph/0601171
Date: Wed, 25 Jan 2006 16:12:40 GMT   (149kb)
Title: Transmittivity measurements by means of squeezed vacuum light
Authors: V. D'Auria, C. de Lisio, A. Porzio, S. Solimeno, M. G. A. Paris
Comments: 14 pages, 8 figures
   A method for measuring the transmittivity of optical samples by using
squeezed--vacuum radiation is illustrated. A squeezed vacuum field generated by
a below--threshold optical parametric oscillator is propagated through a
nondispersive medium and detected by a homodyne apparatus. The variance of the
detected quadrature is used for measuring the transmittivity. With this method
it is drastically reduced the number of photons passing through the sample
during the measurement interval. The results of some tests are reported.
\\ ( ,  149kb)
Paper: cond-mat/0601604
Date: Thu, 26 Jan 2006 04:23:40 GMT   (71kb)
Title: Thermal fluctuations of vortex clusters in two-dimensional BEC
Authors: W. V. Pogosov and K. Machida
Comments: 8 pages, 2 figures
Subj-class: Statistical Mechanics; Other
   We study the thermal fluctuations of vortex positions in small vortex
clusters in a harmonically trapped rotating BEC. It is shown that the
order-disorder transition of two-shells clusters occurs via decoupling of
shells with respect to each other due to strong fluctuations of the phase of
the order parameter. The corresponding "melting" temperature depends strongly
on the commensurability between numbers of vortices in shells. We derive
scaling laws for average angle between shells in terms of number of particles
in the system and temperature and calculate these angles for some particular
values of the coupling constant and rotation speed. We show that "melting" can
be achieved at experimentally attainable parameters. Also studied is the effect
of thermal fluctuations on vortices in an anisotropic trap with small
quadrupole deformation. We show that thermal fluctuations lead to the
decoupling of a vortex cluster from the pinning potential induced by this
deformation. The decoupling temperatures are calculated. It is demonstrated
that pinning energy and average deviation angle of the vortex cluster from the
equilibrium have different asymptotic behaviour for different vortex
configurations, when the trap anisotropy tends to zero, revealing strong
commensurability effects.
\\ ( ,  71kb)
Paper: cond-mat/0601605
Date: Thu, 26 Jan 2006 04:28:12 GMT   (160kb)
Title: Vortex nucleation in rotating BEC: the role of the boundary condition
   for the order parameter
Authors: W. V. Pogosov and K. Machida
Comments: 6 pages, 2 figures
Subj-class: Statistical Mechanics; Other
   We study the process of vortex nucleation in rotating two-dimensional BEC
confined in a harmonic trap. We show that, within the Gross-Pitaevskii theory
with the boundary condition of vanishing of the order parameter at infinity,
topological defects nucleation occurs via the creation of vortex-antivortex
pairs far from the cloud center, where the modulus of the order parameter is
small. Then, vortices move towards the center of the cloud and antivortices
move in the opposite direction but never disappear. We also discuss the role of
surface modes in this process.
\\ ( ,  160kb)
Paper: quant-ph/0601177
Date: Thu, 26 Jan 2006 16:42:42 GMT   (19kb)
Title: Entanglement generation via scattering of two particles with hard-core
Authors: Frank Schm\"user and Dominik Janzing
Comments: 2 figures
   We analyse the entanglement generation in a one dimensional scattering
process. The two colliding particles have a Gaussian wave function and interact
by hard--core repulsion.In our analysis results on the entanglement of two mode
Gaussian states are used. The produced entanglement depends in a non-obvious
way on the parameters ratio of masses and initial widths. The asymptotic
wavefunction of the two particles and its associated ellipse yield additional
geometric insight into these conditions. The difference to the quantitative
analysis of the amount of entanglement generated by beam splitters with
squeezed light is discussed.
\\ ( ,  19kb)
Received on Mon Jan 30 2006 - 14:05:44 EST

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