From: Matthew Davis <mdavis_at_physics.uq.edu.au>

Date: Tue, 10 Oct 2006 10:36:57 +1000 (EST)

Date: Tue, 10 Oct 2006 10:36:57 +1000 (EST)

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

Not so late this time... 27 new preprints last week.

http://www.physics.uq.edu.au/people/mdavis/matts_arXiv/

New preprints:

------------------------------------------------------------------------------

\\

Paper: cond-mat/0609748

Date: Thu, 28 Sep 2006 23:56:57 GMT (42kb)

Title: Quantum Noise Analysis of Spin Systems Realized with Cold Atoms

Authors: R. W. Cherng, Eugene Demler

Comments: 18 pages, 4 figures

Subj-class: Strongly Correlated Electrons; Statistical Mechanics

\\

We consider the use of quantum noise to characterize many-body states of spin

systems realized with ultracold atomic systems. These systems offer a wealth of

experimental techniques for realizing strongly interacting many-body states in

a regime with a large but not macroscropic number of atoms where fluctuations

of an observable such as the magnetization are discernable compared to the mean

value. The full distribution function is experimentally relevant and encodes

high order correlation functions that may distinguish various many-body states.

We apply quantum noise analysis to the Ising model in a transverse field and

find a distinctive even versus odd splitting in the distribution function for

the transverse magnetization that distinguishes between the ordered, critical,

and disordered phases. We also discuss experimental issues relevant for

applying quantum noise analysis for general spin systems and the specific

results obtained for the Ising model.

\\ ( http://arXiv.org/abs/cond-mat/0609748 , 42kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0609761

Date: Fri, 29 Sep 2006 11:10:49 GMT (322kb)

Title: The atomic Bose gas in Flatland

Authors: Zoran Hadzibabic (LKB - Lhomond), Peter Kr\"{u}ger (LKB - Lhomond),

Marc Cheneau (LKB - Lhomond), Baptiste Battelier (LKB - Lhomond), Jean B.

Dalibard (LKB - Lhomond)

Comments: To appear in "ATOMIC PHYSICS 20" Proceedings of the XX International

Conference on Atomic Physics (ICAP)

Proxy: ccsd ccsd-00102179

Subj-class: Other

\\

We describe a recent experiment performed with rubidium atoms ($^{87}$Rb),

aiming at studying the coherence properties of a two-dimensional gas of bosonic

particles at low temperature. We have observed in particular a

Berezinskii--Kosterlitz--Thouless (BKT) type crossover in the system, using a

matter wave heterodyning technique. At low temperatures, the gas is

quasi-coherent on the length scale set by the system size. As the temperature

is increased, the loss of long-range coherence coincides with the onset of the

proliferation of free vortices, in agreement with the microscopic BKT theory.

\\ ( http://arXiv.org/abs/cond-mat/0609761 , 322kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0609774

Date: Fri, 29 Sep 2006 16:15:05 GMT (598kb)

Title: Analysis of Localization Phenomena in Weakly Interacting Disordered

Lattice Gases

Authors: T. Schulte, S. Drenkelforth, J. Kruse, R. Tiemeyer, K. Sacha, J.

Zakrzewski, M. Lewenstein, W. Ertmer, and J.J. Arlt

Comments: 9 pages, 13 figures

Subj-class: Disordered Systems and Neural Networks

\\

Disorder plays a crucial role in many systems particularly in solid state

physics. However, the disorder in a particular system can usually not be chosen

or controlled. We show that the unique control available for ultracold atomic

gases may be used for the production and observation of disordered quantum

degenerate gases. A detailed analysis of localization effects for two possible

realizations of a disordered potential is presented. In a theoretical analysis

clear localization effects are observed when a superlattice is used to provide

a quasiperiodic disorder. The effects of localization are analyzed by

investigating the superfluid fraction and the localization length within the

system. The theoretical analysis in this paper paves a clear path for the

future observation of Anderson-like localization in disordered quantum gases.

\\ ( http://arXiv.org/abs/cond-mat/0609774 , 598kb)

------------------------------------------------------------------------------

\\

Paper: quant-ph/0609225

Date: Fri, 29 Sep 2006 06:49:47 GMT (15kb)

Title: Generating quadrature squeezing in an atom laser through

self-interaction

Authors: Mattias T. Johnsson and Simon A. Haine

Comments: 4 pages, 3 figures

\\

We describe a scheme for creating a quadrature-squeezed atom laser that does

not require squeezed light as an input. The beam becomes squeezed due to

nonlinear interactions between the atoms in the beam in an analogue to optical

Kerr squeezing. We develop an analytic model of the process which we compare to

a detailed stochastic simulation of the system using phase space methods.

Finally we show that significant squeezing can be obtained in an experimentally

realistic system and suggest ways of increasing the tunability of the

squeezing.

\\ ( http://arXiv.org/abs/quant-ph/0609225 , 15kb)

------------------------------------------------------------------------------

\\

Paper: quant-ph/0609236

Date: Fri, 29 Sep 2006 17:37:07 GMT (274kb)

Title: A fast and robust approach to long-distance quantum communication with

atomic ensembles

Authors: L. Jiang, J. M. Taylor, M. D. Lukin

Comments: 6 pages, 4 figures

\\

Quantum communication holds promise for cryptography, teleportation of

arbitrary quantum states, and violation of Bell's inequalities over long

distances. While commercial implementation of simple quantum communication

protocols are well established, attenuation in optical fibers makes longer

distances exponentially challenging. Quantum repeaters overcome the time

overhead associated with fiber attenuation by using a quantum memory and local

quantum operations. A simple implementation uses atomic ensembles and linear

optics (Duan, Lukin, Cirac, Zoller, Nature 414, 413 (2001)). Motivated by

experimental progress, here we develop an efficient scheme compatible with the

active purification of arbitrary errors. Using similar resources as the DLCZ

approach, our approach intrinsically purifies leakage out of the logical

subspace and all errors within the logical subspace, leading to greatly

improved performance in the presence of experimental inefficiencies. We find

that about one, 1280 km-distant entangled pair per minute could be realized

with a fidelity sufficient to violate Bell's inequality.

\\ ( http://arXiv.org/abs/quant-ph/0609236 , 274kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0610006

Date: Sat, 30 Sep 2006 06:47:52 GMT (735kb)

Title: Finite Temperature Effects in Ultracold Fermi Gases

Authors: K. Levin and Qijin Chen

Comments: Lecture given at the International School of Physics "Enrico Fermi"

-- the 2006 Varenna Summer School on "Ultracold Fermi Gases", 27 pages, 17

figures

Subj-class: Strongly Correlated Electrons; Superconductivity

\\

This article is written as a Lecture given in the 2006 Varenna Summer School

on "Ultracold Fermi Gases". Here we present a review of BCS--Bose Einstein

condensation (BEC) crossover theory with emphasis on finite temperature

effects. We discuss the role of temperature $T$ as it enters a theoretical

formalism which is based on the standard BCS-Leggett ground state. We also

discuss the role of temperature in the context of experiments ranging from

thermometric issues to signatures of superfluidity. Particularly important to

this discussion is the novel normal state associated with the crossover regime,

intermediate between BCS and BEC. The experimental evidence for this unusual

normal state (associated with pre-formed pairs) and its counterpart below $T_c$

(associated with non-condensed pairs) is presented in the context of different

experiments. We end with a discussion of finite temperature effects in spin

polarized superfluids, where $T$ is found to play a crucial role in both theory

and experiment.

\\ ( http://arXiv.org/abs/cond-mat/0610006 , 735kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0610011

Date: Sun, 1 Oct 2006 00:06:11 GMT (159kb)

Title: BEC-BCS Crossover in the Epsilon Expansion

Authors: Jiunn-Wei Chen and Eiji Nakano

Comments: 9 pages, 3 figures

Subj-class: Other

\\

The epsilon expansion (expansion around four spacial dimensions) developed by

Nishida and Son for a cold fermi gas with infinite scattering length is

extended to finite scattering length to study the BEC-BCS crossover. A

resummation of higher order logarithms and a suitable extension of fermion

coupling in d-dimensions are developed in order to apply the theory in the BCS

regime. The ratio between the chemical potential and the Fermi energy, mu/eF,

is computed to next-to-leading order in the epsilon expansion as a function of

eta=1/(a kF), where a is the scattering length and kF is the Fermi momentum in

a non-interacting system. Near the unitarity limit eta->0, we found

mu/eF=0.475-0.707 eta-0.5 eta^2. Near the BEC limit eta->infinity,

mu/eF=0.062/eta - eta^2, while near the BCS limit eta->-infinity,

mu/eF=1+0.707/eta. Overall good agreement with Quantum Monte Carlo results is

found.

\\ ( http://arXiv.org/abs/cond-mat/0610011 , 159kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0610014

Date: Sat, 30 Sep 2006 13:30:08 GMT (567kb)

Title: Driven Macroscopic Quantum Tunneling of Ultracold Atoms in Engineered

Optical Lattices

Authors: Ramaz Khomeriki, Stefano Ruffo, Sandro Wimberger

Subj-class: Mesoscopic Systems and Quantum Hall Effect; Superconductivity

\\

Coherent macroscopic tunneling of a Bose-Einstein condensate between two

parts of an optical lattice separated by an energy barrier is theoretically

investigated. We show that by a pulsewise change of the barrier height, it is

possible to switch between tunneling regime and a self-trapped state of the

condensate. This property of the system is explained by effectively reducing

the dynamics to the nonlinear problem of a particle moving in a double square

well potential. The analysis is made for both attractive and repulsive

interatomic forces, and it highlights the experimental relevance of our

findings.

\\ ( http://arXiv.org/abs/cond-mat/0610014 , 567kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0610016

Date: Sat, 30 Sep 2006 23:40:42 GMT (13kb)

Title: Ground and excited states of spinor Fermi gases in tight waveguides and

the Lieb-Liniger-Heisenberg model

Authors: M. D. Girardeau

Comments: 4 pages, 2 figures, revtex4. To be submitted to Phys. Rev. Lett

Subj-class: Soft Condensed Matter

\\

The ground and excited states of a one-dimensional (1D) spin-1/2 Fermi gas

(SFG) with both attractive zero-range odd-wave interactions and repulsive

zero-range even-wave interactions are mapped exactly to a 1D

Lieb-Liniger-Heisenberg (LLH) model with delta-function repulsions depending on

isotropic Heisenberg spin-spin interactions, such that the complete SFG and LLH

energy spectra are identical. The ground state in the ferromagnetic phase is

given exactly by the Lieb-Liniger (LL) Bethe ansatz, and that in the

antiferromagnetic phase by a variational method combining Bethe ansatz

solutions of the LL and 1D Heisenberg models. There are excitation branches

corresponding to LL type I and II phonons and spin waves, the latter behaving

quadratically for small wave number in the ferromagnetic phase and linearly in

the antiferromagnetic phase.

\\ ( http://arXiv.org/abs/cond-mat/0610016 , 13kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0610024

Date: Sun, 1 Oct 2006 19:16:31 GMT (28kb)

Title: Entanglement from the Dynamics of an Ideal Bose Gas in a Lattice

Authors: Sougato Bose

Comments: 4 pages, 3 figures

Subj-class: Other

\\

We show how the remotest sites of a finite lattice can be entangled, with the

amount of entanglement exceeding that of a singlet, solely through the dynamics

of an ideal Bose gas in a special initial state in the lattice. When additional

occupation number measurements are made on the intermediate lattice sites, then

the amount of entanglement and the length of the lattice separating the

entangled sites can be significantly enhanced. The entanglement generated by

this dynamical procedure is found to be higher than that for the ground state

of an ideal Bose gas in the same lattice. A second dynamical evolution is shown

to verify the existence of these entangled states, as well entangle qubits

belonging to well separated quantum registers.

\\ ( http://arXiv.org/abs/cond-mat/0610024 , 28kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0610047

Date: Mon, 2 Oct 2006 18:05:59 GMT (693kb)

Title: A ring accelerator for matter-wave solitons

Authors: Alicia V. Carpentier and Humberto Michinel

Comments: 4 pages, 6 figures

Subj-class: Soft Condensed Matter

\\

We describe a new technique to accelerate and control a confined cloud of

ultracold neutral atoms. In our configuration, a Bose-Einstein Condensate

trapped in a ring is accelerated by using an amplitude-modulated optical

potential. The spreading of the atomic cloud is avoided by an adequate tuning

of the scattering length. We also discuss other variations that offer new

possibilities of robust control of atomic solitons. Our numerical results show

that this cold matter accelerator is easily accessible in the frame of current

experiments.

\\ ( http://arXiv.org/abs/cond-mat/0610047 , 693kb)

------------------------------------------------------------------------------

\\

Paper: quant-ph/0610008

Date: Sun, 1 Oct 2006 19:47:06 GMT (9kb)

Title: Entanglement of Josephson junctions revisited

Authors: Robert Alicki

Comments: 6 pages

\\

The recent experimental evidence for entangled states of two Josephson

junction (JJ) qubits seems to support the picture of JJ as a "macroscopic

quantum system". On the other hand the interpretation of experimental data

strongly depends on the assumed theoretical model. Namely, the qubit states are

supposed to be spanned by the orthogonal quantum states of a certain

well-separated subsystem. We analyse the possible states of JJ for three models

: two-mode Bose-Hubbard model, its large $N$ aproximation called quantum-phase

model, and the many-body description within the mean-field approximation

(Gross-Pitaevski equation). While the first two models support the picture of

JJ being a quantum subsystem of a single degree of freedom, the last approach

yields the structure of accessible quantum states which cannot correspond to a

qubit. The phenomenology of the mean-field model is briefly discussed and, in

particular, the absence of observable entanglement for two coupled JJ's is

shown. As the many-body mean-field theory seems to be more fundamental and

better suited for the description of critical phenomena than the others, the

standard interpretation of the JJ experiments becomes questionable.

\\ ( http://arXiv.org/abs/quant-ph/0610008 , 9kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0610053

Date: Tue, 3 Oct 2006 00:38:50 GMT (986kb)

Title: Transmission and Reflection of Bose-Einstein Condensates Incident on a

Gaussian Potential Barrier

Authors: A.M. Martin, R.G. Scott, T.M. Fromhold

Comments: 9 pages, 9 figures

Subj-class: Other

\\

We investigate how Bose-Einstein condensates, whose initial state is either

irrotational or contains a single vortex, scatter off a one-dimensional

Gaussian potential barrier. We find that for low atom densities the vortex

structure within the condensate is maintained during scattering, whereas at

medium and high densities, multiple additional vortices can be created by the

scattering process, resulting in complex dynamics and disruption of the atom

cloud. This disruption originates from two different mechanisms associated

respectively with the initial rotation of the atom cloud and the interference

between the incident and reflected matter waves. We investigate how the

reflection probability depends on the vorticity of the initial state and on the

incident velocity of the Bose-Einstein condensate. To interpret our results, we

derive a general analytical expression for the reflection coefficient of a

rotating Bose-Einstein condensate that scatters off a spatially-varying

one-dimensional potential.

\\ ( http://arXiv.org/abs/cond-mat/0610053 , 987kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0610071

Date: Tue, 3 Oct 2006 13:19:25 GMT (257kb)

Title: The ground states of spin-3 Bose-Einstein condensates for conserved

magnetization

Authors: Harri M\"akel\"a, Kalle-Antti Suominen

Comments: 7 pages, 3 figures

Subj-class: Other

\\

We calculate the ground states and ground state phase diagrams of

Bose-Einstein condensates of spin-3 atoms under the assumption of conserved

magnetization. We especially concentrate on the ground states of a chromium

condensate. In chromium the magnetic dipole-dipole interaction enables

magnetization changing collisions, but in a strong magnetic field these are

suppressed. In the calculation of the phase diagrams we neglect the

contribution from the dipole-dipole interaction, but discuss its effects at the

end of the paper. We show that the ground state of a chromium condensate does

not seem to depend on whether or not the dipole-dipole interaction is taken

into attention.

\\ ( http://arXiv.org/abs/cond-mat/0610071 , 257kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0610072

Date: Tue, 3 Oct 2006 13:17:28 GMT (57kb)

Title: Construction of a giant vortex state in a trapped Fermi system

Authors: Emil Lundh

Comments: 12 pages, 14 figure files

Subj-class: Other

\\

A superfluid atomic Fermi system may support a giant vortex if the trapping

potential is anharmonic. In such a potential, the single-particle spectrum has

a positive curvature as a function of angular momentum. A tractable model is

put up in which the lowest and next lowest Landau levels are occupied.

Different parameter regimes are identified and characterized. Due to the

dependence of the interaction on angular momentum quantum number, the Cooper

pairing is at its strongest not only close to the Fermi level, but also close

to the energy minimum. It is shown that the gas is superfluid in the interior

of the toroidal density distribution and normal in the outer regions.

Furthermore, the pairing may give rise to a localized density depression in

configuration space.

\\ ( http://arXiv.org/abs/cond-mat/0610072 , 57kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0610079

Date: Tue, 3 Oct 2006 15:26:04 GMT (180kb)

Title: Equilibrium phase diagrams on degenerate Fermi gas with Feshbach

resonance

Authors: S. Watabe, T. Nikuni, N. Nygaard, J. E. Williams, and C. W. Clark

Comments: 16 pages, 8 figures

Subj-class: Other

\\

We determine the adiabatic phase diagram for a resonantly-coupled system of

Fermi atoms and Bose molecules confined in the harmonic trap by using the local

density approximation. The adiabatic phase diagram shows the fermionic

condensate fraction composed of condensed molecules and Cooper pair atoms. The

key idea of our work is conservation of entropy through the adiabatic process,

extending the study of Williams et al. [Williams et al., New J. Phys. 6, 123

(2004)] for an ideal gas mixture to include the resonant interaction in a

mean-field theory. We also calculate the molecular conversion efficiency as a

function of initial temperature. Our work helps to understand recent

experiments on the BCS-BEC crossover, in terms of the initial temperature

measured before a sweep of the magnetic field.

\\ ( http://arXiv.org/abs/cond-mat/0610079 , 180kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0610082

Date: Tue, 3 Oct 2006 15:37:21 GMT (35kb)

Title: Matter wave solitons at finite temperatures

Authors: B. Jackson, C. F. Barenghi, and N. P. Proukakis

Comments: 6 pages, 2 figures, submitted to the Proceedings of QFS '06

Subj-class: Statistical Mechanics

\\

We consider the dynamics of a dark soliton in an elongated harmonically

trapped Bose-Einstein condensate. A central question concerns the behavior at

finite temperatures, where dissipation arises due to the presence of a thermal

cloud. We study this problem using coupled Gross-Pitaevskii and $N$-body

simulations, which include the mean field coupling between the condensate and

thermal cloud. We find that the soliton decays relatively quickly even at very

low temperatures, with the decay rate increasing with rising temperature.

\\ ( http://arXiv.org/abs/cond-mat/0610082 , 35kb)

------------------------------------------------------------------------------

\\

Paper (*cross-listing*): hep-lat/0609054

Date: Wed, 27 Sep 2006 09:06:08 GMT (58kb)

Title: Field theoretic study of a cold Fermi gas in the unitary limit

Authors: Matthew Wingate

Comments: 7 pages. Talk delivered at The XXIV International Symposium on

Lattice Field Theory, Tucson, Arizona, July 2006. To appear in Proceedings of

Science

Subj-class: High Energy Physics - Lattice; Other; Superconductivity

\\

Trapped and cooled gases of alkali atoms can be manipulated to exhibit a

variety of interesting phenomena. For example, dilute gases of fermionic atoms,

in 2 hyperfine states, can be cooled to temperatures where they become

superfluid. An external field can be applied to tune the scattering length a.

When |a| exceeds the interparticle spacing, nonperturbative tools are needed to

study the system theoretically. The unitary limit, |a|\to\infty, is

particularly interesting due to its universality and symmetry. Lattice field

theory and effective field theory can be used to systematically calculate

properties of this system. Results are presented for the finite temperature

phase transition and for behavior near zero temperature.

\\ ( http://arXiv.org/abs/hep-lat/0609054 , 59kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0610114

Date: Wed, 4 Oct 2006 12:49:48 GMT (405kb)

Title: Dynamical localization of matter wave solitons in managed barrier

potentials

Authors: Fatkhulla Kh. Abdullaev, Josselin Garnier

Comments: 10 pages, 6 figures

Subj-class: Other; Soft Condensed Matter

\\

The bright matter wave soliton propagation through a barrier with a rapidly

oscillating position is investigated. The averaged over rapid oscillations

Gross-Pitaevskii (GP) equation is derived. It is shown that the soliton is

dynamically trapped by the effective double-barrier.

The analytical predictions for the soliton effective dynamics is confirmed by

the numerical simulations of the full GP equation.

\\ ( http://arXiv.org/abs/cond-mat/0610114 , 405kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0610116

Date: Wed, 4 Oct 2006 14:43:56 GMT (18kb)

Title: Resonant Dimer Relaxation in Cold Atoms with a Large Scattering Length

Authors: Eric Braaten (Ohio State U.), H.-W. Hammer (Bonn U.)

Comments: 4 pages, 2 ps figures

Report-no: HISKP-TH-06-26

Subj-class: Other

\\

Efimov physics refers to universal phenomena associated with a discrete

scaling symmetry in the 3-body problem with a large scattering length. The

first experimental evidence for Efimov physics was the recent observation of a

resonant peak in the 3-body recombination rate for 133Cs atoms with large

negative scattering length. There can also be resonant peaks in the atom-dimer

relaxation rate for large positive scattering length. We calculate the

atom-dimer relaxation rate as a function of temperature and show how

measurements of the relaxation rate can be used to determine accurately the

parameters that govern Efimov physics.

\\ ( http://arXiv.org/abs/cond-mat/0610116 , 18kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0610117

Date: Wed, 4 Oct 2006 14:52:45 GMT (203kb)

Title: The Mathematics of the Bose Gas and its Condensation

Authors: Elliott H. Lieb, Robert Seiringer, Jan Philip Solovej, Jakob Yngvason

Comments: 213 pages. Slightly revised and extended version of Oberwolfach

Seminar Series, Vol. 34, Birkhaeuser (2005)

Subj-class: Statistical Mechanics

\\

This book surveys results about the quantum mechanical many-body problem of

the Bose gas that have been obtained by the authors over the last seven years.

These topics are relevant to current experiments on ultra-cold gases; they are

also mathematically rigorous, using many analytic techniques developed over the

years to handle such problems. Some of the topics treated are the ground state

energy, the Gross-Pitaevskii equation, Bose-Einstein condensation,

superfluidity, one-dimensional gases, and rotating gases. The book also

provides a pedagogical entry into the field for graduate students and

researchers.

\\ ( http://arXiv.org/abs/cond-mat/0610117 , 203kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0610121

Date: Wed, 4 Oct 2006 19:29:48 GMT (68kb)

Title: Phase separation in a two species Bose mixture

Authors: T. Mishra, Ramesh V. Pai, B. P. Das

Comments: 5 pages, 5 figures

Subj-class: Statistical Mechanics; Other

\\

We study the ground state quantum phase diagram for a two species Bose

mixture in a one-dimensional optical lattice using the finite size density

matrix renormalization group(FSDMRG) method. We discuss our results for

different combinations of inter and intra species interaction strengths with

commensurate and incommensurate fillings of the bosons. The phases we have

obtained are superfluid, Mott insulator and a novel phase separation, where

different species reside in spatially separate regions. The spatially separated

phase is further classified into phase separated superfluid(PS-SF) and Mott

insulator(PS-MI). The phase separation appears for all the fillings we have

considered, whenever the inter-species interaction is slightly larger than the

intra-species interactions.

\\ ( http://arXiv.org/abs/cond-mat/0610121 , 68kb)

------------------------------------------------------------------------------

\\

Paper: quant-ph/0610019

Date: Tue, 3 Oct 2006 20:17:24 GMT (325kb)

Title: Realization of a superconducting atom chip

Authors: Thomas Nirrengarten (LKB - Lhomond), Angie Qarry (LKB - Lhomond),

C\'{e}dric Roux (LKB - Lhomond), Andreas Emmert (LKB - Lhomond), Gilles

Nogues (LKB - Lhomond), Michel Brune (LKB - Lhomond), Jean-Michel Raimond

(LKB - Lhomond), Serge Haroche (LKB - Lhomond, CDF)

Comments: Submitted to Phys. Rev. Lett

Proxy: ccsd ccsd-00103290

\\

We have trapped rubidium atoms in the magnetic field produced by a

superconducting atom chip operated at liquid Helium temperatures. Up to

$8.2\cdot 10^5$ atoms are held in a Ioffe-Pritchard trap at a distance of 440

$\mu$m from the chip surface, with a temperature of 40 $\mu$K. The trap

lifetime reaches 115 s at low atomic densities. These results open the way to

the exploration of atom--surface interactions and coherent atomic transport in

a superconducting environment, whose properties are radically different from

normal metals at room temperature.

\\ ( http://arXiv.org/abs/quant-ph/0610019 , 325kb)

------------------------------------------------------------------------------

\\

Paper: physics/0610022

Date: Tue, 3 Oct 2006 21:11:49 GMT (580kb)

Title: Compression and localization of an atomic cloud in a time dependent

optical lattice

Authors: Will Williams, M. Saffman

Comments: 9 Figures

Subj-class: Atomic Physics

\\

We analyze a method to compress a cloud of cold atoms in a far off resonance

optical lattice by dynamically changing the lattice parameters while cooling

the atoms with optical molasses. Particle motion in the time dependent lattice

is studied numerically using a three dimensional semiclassical model. We show

that smoothly varying the lattice spacing from a large to a small value results

in compression of more than 75% of the atoms initially in a Gaussian

distributed cloud with standard deviation of 50 $\mu$m into a single site of a

two-dimensional lattice. The lattice site has an area of $A=0.76 \lambda^2$

with $\lambda$ the wavelength of the trapping beam. We demonstrate that an

increase in the optical depth by a factor of at least 175 is possible.

\\ ( http://arXiv.org/abs/physics/0610022 , 580kb)

------------------------------------------------------------------------------

\\

Paper: physics/0610027

Date: Wed, 4 Oct 2006 13:04:49 GMT (924kb)

Title: Transport of launched cold atoms with a laser guide and pulsed magnetic

fields

Authors: Matthew J Pritchard, Aidan S Arnold, Simon L Cornish, David W

Hallwood, Chris V S Pleasant and Ifan G Hughes

Comments: 19 pages 11 figures

Subj-class: Atomic Physics; Optics

\\

We propose the novel combination of a laser guide and magnetic lens to

transport a cold atomic cloud. We have modelled the loading and guiding of a

launched cloud of cold atoms with the optical dipole force. We discuss the

optimum strategy for loading typically 30% of the atoms from a MOT and guiding

them vertically through 22cm. However, although the atoms are tightly confined

transversely, thermal expansion in the propagation direction still results in a

density loss of two orders of magnitude. By combining the laser guide with a

single impulse from a magnetic lens we show one can actually increase the

density of the guided atoms by a factor of 10.

\\ ( http://arXiv.org/abs/physics/0610027 , 924kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0610135

Date: Thu, 5 Oct 2006 04:34:07 GMT (262kb)

Title: Complexity in parametric Bose-Hubbard Hamiltonians and structural

analysis of eigenstates

Authors: Moritz Hiller, Tsampikos Kottos, and T. Geisel

Comments: 4 pages, 4 figures

Subj-class: Other

Journal-ref: Phys. Rev. A 73, 061604(R), 2006

DOI: 10.1103/PhysRevA.73.061604

\\

We consider a family of chaotic Bose-Hubbard Hamiltonians (BHH) parameterized

by the coupling strength $k$ between neighboring sites. As $k$ increases the

eigenstates undergo changes, reflected in the structure of the Local Density of

States. We analyze these changes, both numerically and analytically, using

perturbative and semiclassical methods. Although our focus is on the quantum

trimer, the presented methodology is applicable for the analysis of longer

lattices as well.

\\ ( http://arXiv.org/abs/cond-mat/0610135 , 262kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0610162

Date: Thu, 5 Oct 2006 19:53:40 GMT (21kb)

Title: Discrete symmetries and 1/3-quantum vortices in condensates of F=2 cold

atoms

Authors: Gordon W. Semenoff and Fei Zhou (UBC)

Comments: 4 pages, 2 figures included

Subj-class: Other

\\

In this Letter we study discrete symmetries of mean field manifolds of

condensates of F=2 cold atoms, and various unconventional quantum vortices.

Discrete quaternion symmetries result in two species of spin defects that can

only appear in integer vortices while {\em cyclic} symmetries are found to

result in a phase shift of $2\pi/3$ (or $4\pi/3$) and therefore 1/3- (or 2/3-)

quantum vortices in condensates. We also briefly discuss quaternion spin

vortices in biaxial nematic condensates, and 1/3-quantum vortices in

condensates of trimers.

\\ ( http://arXiv.org/abs/cond-mat/0610162 , 21kb)

------------------------------------------------------------------------------

\\

Paper: quant-ph/0610029

Date: Thu, 5 Oct 2006 01:49:38 GMT (880kb)

Title: Cavity QED determination of atomic number statistics in optical lattices

Authors: W. Chen, D. Meiser, and P. Meystre

Comments: 10 pages revtex, 13 figures

\\

We study the reflection of two counter-propagating modes of the light field

in a ring resonator by ultracold atoms either in the Mott insulator state or in

the superfluid state of an optical lattice. We obtain exact numerical results

for a simple two-well model and carry out statistical calculations appropriate

for the full lattice case. We find that the dynamics of the reflected light

strongly depends on both the lattice spacing and the state of the matter-wave

field. Depending on the lattice spacing, the light field is sensitive to

various density-density correlation functions of the atoms. The light field and

the atoms become strongly entangled if the latter are in a superfluid state, in

which case the photon statistics typically exhibit complicated multimodal

structures.

\\ ( http://arXiv.org/abs/quant-ph/0610029 , 880kb)

------------------------------------------------------------------------------

Replaced preprints:

------------------------------------------------------------------------------

\\

Paper: cond-mat/0604186

replaced with revised version Fri, 29 Sep 2006 09:50:52 GMT (18kb)

Title: BEC-BCS crossover in an optical lattice

Authors: Arnaud Koetsier, D. B. M. Dickerscheid, H. T. C. Stoof

Comments: 4 pages, 3 figures

Report-no: ITP-UU-06/17

Subj-class: Statistical Mechanics

Journal-ref: Phys. Rev. A 74, 033621 (2006)

DOI: 10.1103/PhysRevA.74.033621

\\ ( http://arXiv.org/abs/cond-mat/0604186 , 18kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0606345

replaced with revised version Fri, 29 Sep 2006 03:28:00 GMT (293kb)

Title: First-principles quantum simulations of dissociation of molecular

condensates: Atom correlations in momentum space

Authors: C.M. Savage, P.E. Schwenn, and K.V. Kheruntsyan

Comments: Final published version, with updated references and minor

modifications

Subj-class: Other; Statistical Mechanics

Journal-ref: Phys. Rev. A 74, 033620 (2006)

DOI: 10.1103/PhysRevA.74.033620

\\ ( http://arXiv.org/abs/cond-mat/0606345 , 293kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0606470

replaced with revised version Thu, 28 Sep 2006 21:21:49 GMT (46kb)

Title: BCS-BEC crossover on the two-dimensional honeycomb lattice

Authors: Erhai Zhao, Arun Paramekanti (University of Toronto)

Comments: Revised - added section on the Fermi surface evolution, corrected

error in superfluid density, added possible implications for cuprates

Subj-class: Superconductivity; Strongly Correlated Electrons

\\ ( http://arXiv.org/abs/cond-mat/0606470 , 46kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0607004

replaced with revised version Thu, 28 Sep 2006 22:58:02 GMT (388kb)

Title: Evidence for Superfluidity of Ultracold Fermions in an Optical Lattice

Authors: J. K. Chin, D. E. Miller, Y. Liu, C. Stan, W. Setiawan, C. Sanner, K.

Xu, W. Ketterle

Comments: accepted for publication in Nature

Subj-class: Other

\\ ( http://arXiv.org/abs/cond-mat/0607004 , 388kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0607297

replaced with revised version Thu, 28 Sep 2006 23:34:14 GMT (138kb)

Title: Melting of Discrete Vortices via Quantum Fluctuations

Authors: Chaohong Lee, Tristram J. Alexander, and Yuri S. Kivshar

Comments: Revised version, 4 pages, 5 figures, Accepted for publication in

Physical Review Letters

Subj-class: Other

\\ ( http://arXiv.org/abs/cond-mat/0607297 , 138kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0607361

replaced with revised version Fri, 29 Sep 2006 08:38:42 GMT (87kb)

Title: Collective excitations of a Bose-Einstein condensate in an anharmonic

trap

Authors: Guan-Qiang Li, Li-Bin Fu, Ju-Kui Xue, Xu-Zong Chen, and Jie Liu

Comments: 5 pages, 4 figures

Subj-class: Mesoscopic Systems and Quantum Hall Effect

\\ ( http://arXiv.org/abs/cond-mat/0607361 , 87kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0609337

replaced with revised version Fri, 29 Sep 2006 08:17:20 GMT (386kb)

Title: Quantum Entanglement Manifestation of Transition to Nonlinear

Self-trapping for Bose-Einstein Condensates in a Symmetric Double-Well

Authors: Li-Bin Fu and Jie Liu

Comments: 6 pages, 5 figures

Subj-class: Mesoscopic Systems and Quantum Hall Effect

\\ ( http://arXiv.org/abs/cond-mat/0609337 , 386kb)

------------------------------------------------------------------------------

\\

Paper: quant-ph/0509094

replaced with revised version Fri, 29 Sep 2006 17:13:55 GMT (29kb)

Title: Single-cell atomic quantum memory for light

Authors: Tomas Opatrny

Comments: 6 pages, 2 figures, to be published in Phys. Rev. A

\\ ( http://arXiv.org/abs/quant-ph/0509094 , 29kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0510194

replaced with revised version Mon, 2 Oct 2006 19:38:26 GMT (144kb)

Title: Ramping fermions in optical lattices across a Feshbach resonance

Authors: Helmut G. Katzgraber, Aniello Esposito, Matthias Troyer

Comments: 9 pages, 7 figures

Subj-class: Other

Journal-ref: Phys. Rev. A 74, 043602 (2006)

DOI: 10.1103/PhysRevA.74.043602

\\ ( http://arXiv.org/abs/cond-mat/0510194 , 144kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0511294

replaced with revised version Mon, 2 Oct 2006 17:21:43 GMT (836kb)

Title: Variational Cluster Perturbation Theory for Bose-Hubbard models

Authors: W. Koller and N. Dupuis

Comments: v1) 10 pages, 6 figures. v2) Final version as published

Subj-class: Other; Statistical Mechanics

Journal-ref: J. Phys.: Condens. Matter 18 (2006) 9525-9540

DOI: 10.1088/0953-8984/18/41/019

\\ ( http://arXiv.org/abs/cond-mat/0511294 , 836kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0602334

replaced with revised version Mon, 2 Oct 2006 16:49:23 GMT (111kb)

Title: Hysteresis effects in rotating Bose-Einstein condensates

Authors: B. Jackson and C. F. Barenghi

Comments: 16 pages, 7 figures; revised after referees' reports

Subj-class: Statistical Mechanics

\\ ( http://arXiv.org/abs/cond-mat/0602334 , 111kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0605198

replaced with revised version Mon, 2 Oct 2006 14:26:21 GMT (738kb)

Title: Cooling toolbox for atoms in optical lattices

Authors: M. Popp, J.-J. Garcia-Ripoll, K. G. H. Vollbrecht and J. I. Cirac

Comments: 14 pages, 13 figures

Subj-class: Other

Journal-ref: New J. Phys. 8, 164 (2006)

\\ ( http://arXiv.org/abs/cond-mat/0605198 , 738kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0605207

replaced with revised version Mon, 2 Oct 2006 19:02:24 GMT (43kb)

Title: Entanglement entropy and entanglement witnesses in models of strongly

interacting low-dimensional fermions

Authors: V. V. Fran\c{c}a and K. Capelle

Comments: 5 pages, 5 figures, accepted by PRA

Subj-class: Strongly Correlated Electrons; Statistical Mechanics

\\ ( http://arXiv.org/abs/cond-mat/0605207 , 43kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0607463

replaced with revised version Sat, 30 Sep 2006 01:06:06 GMT (14kb)

Title: Quantum insulating states of F=2 cold atoms in optical lattices

Authors: Fei Zhou and Gordon W. Semenoff (PITP and UBC)

Comments: 4 pages, 1 figure included; references updated. To appear in Phys.

Rev. Lett

Subj-class: Other

\\ ( http://arXiv.org/abs/cond-mat/0607463 , 14kb)

------------------------------------------------------------------------------

\\

Paper: physics/0609145

replaced with revised version Fri, 29 Sep 2006 20:10:14 GMT (73kb)

Title: Optical Feshbach resonances of Alkaline-Earth atoms in a 1D or 2D

optical lattice

Authors: Pascal Naidon and Paul S. Julienne

Comments: 12 pages, 4 figures. Typos were corrected and a connection was made

to the fermionization of bosons

Subj-class: Atomic Physics

\\ ( http://arXiv.org/abs/physics/0609145 , 73kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0606043

replaced with revised version Tue, 3 Oct 2006 19:45:17 GMT (397kb)

Title: Zero Temperature Thermodynamics of Asymmetric Fermi Gases at Unitarity

Authors: Aurel Bulgac and Michael McNeil Forbes

Comments: 4 pages and 3 figures, revtex4 and an additional extensive appendix

meant to appear only online

Report-no: NT_at_UW-06-12

Subj-class: Superconductivity

\\ ( http://arXiv.org/abs/cond-mat/0606043 , 397kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0607434

replaced with revised version Tue, 3 Oct 2006 07:44:26 GMT (245kb)

Title: Thermal dissipation in quantum turbulence

Authors: Michikazu Kobayashi and Makoto Tsubota

Comments: 4 pages, 6 figures, submitted to APS

Subj-class: Disordered Systems and Neural Networks; Statistical Mechanics

\\ ( http://arXiv.org/abs/cond-mat/0607434 , 245kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0608135

replaced with revised version Mon, 2 Oct 2006 22:36:21 GMT (376kb)

Title: Disruption of reflecting Bose-Einstein condensates due to inter-atomic

interactions and quantum noise

Authors: R.G. Scott, D.A.W. Hutchinson and C.W. Gardiner

Comments: 5 figures

Subj-class: Other

\\ ( http://arXiv.org/abs/cond-mat/0608135 , 376kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0605102

replaced with revised version Tue, 3 Oct 2006 21:21:53 GMT (242kb)

Title: Topological defects and the superfluid transition of the $s=1$ spinor

condensate in two dimensions

Authors: Subroto Mukerjee, Cenke Xu, and J. E. Moore

Comments: 4 pages, 2 figures; published version

Subj-class: Other

Journal-ref: Phys. Rev. Lett. 97, 120406 (2006)

\\ ( http://arXiv.org/abs/cond-mat/0605102 , 242kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0606265

replaced with revised version Wed, 4 Oct 2006 18:20:11 GMT (153kb)

Title: Spinful bosons in an optical lattice

Authors: Sara Bergkvist, Ian McCulloch, Anders Rosengren

Comments: Minor revisions and clarifications

Subj-class: Other

\\ ( http://arXiv.org/abs/cond-mat/0606265 , 153kb)

------------------------------------------------------------------------------

\\

Paper: cond-mat/0608455

replaced with revised version Wed, 4 Oct 2006 17:23:01 GMT (823kb)

Title: Deformation of a Trapped Fermi Gas with Unequal Spin Populations

Authors: G. B. Partridge, Wenhui Li, Y. A. Liao, R. G. Hulet, M. Haque & H. T.

C. Stoof

Comments: Accepted for publication in Physical Review Letters

Subj-class: Other; Superconductivity

\\ ( http://arXiv.org/abs/cond-mat/0608455 , 823kb)

-----------------------------------------------------------------------------

Till next week,

Matt.

-- ========================================================================= 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/ ========================================================================= Matt's arXiv selection: weekly summary of cold-atom papers from arXiv.org http://www.physics.uq.edu.au/people/mdavis/matts_arXiv/ ========================================================================= Legal stuff: Unless stated otherwise, this e-mail represents only the views of the sender and not the views of the University of Queensland =========================================================================Received on Tue Oct 10 2006 - 10:36:57 EST

*
This archive was generated by hypermail 2.2.0
: Thu May 08 2008 - 11:51:41 EST
*