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

Date: Thu, 12 Mar 2009 09:12:45 +1000

Date: Thu, 12 Mar 2009 09:12:45 +1000

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

This week there were 31 new preprints and 9 replacements.

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arXiv:0901.2425

Date: Fri, 16 Jan 2009 09:06:04 GMT (220kb)

Title: Green-function method in the theory of ultraslow electromagnetic waves

in an ideal gas with Bose-Einstein condensates

Authors: Yurii Slyusarenko and Andrii Sotnikov

Categories: cond-mat.stat-mech cond-mat.other

Comments: 15 pages, 6 figures

Journal-ref: Phys. Rev. A 78, 2008, 053622

DOI: 10.1103/PhysRevA.78.053622

\\

We propose a microscopic approach describing the interaction of an ideal gas

of hydrogenlike atoms with a weak electromagnetic field. This approach is based

on the Green-function formalism and an approximate formulation of the method of

second quantization for quantum many-particle systems in the presence of bound

states of particles. The dependencies of the propagation velocity and damping

rate of electromagnetic pulses on the microscopic characteristics of the system

are studied for a gas of hydrogenlike atoms. For a Bose-Einstein condensate of

alkali-metal atoms we find the conditions when the electromagnetic waves of

both the optical and microwave regions are slowed. In the framework of the

proposed approach, the influence of an external homogeneous and static magnetic

field on the slowing phenomenon is studied.

\\ ( http://arxiv.org/abs/0901.2425 , 220kb)

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arXiv:0901.2487

Date: Fri, 16 Jan 2009 14:05:23 GMT (301kb)

Title: New superfluid states - a first glance

Authors: George Kastrinakis

Categories: cond-mat.supr-con cond-mat.str-el

Comments: First report on the new superfluid states

\\

We introduce two new fermionic variational wavefunctions, which sustain

superfluidity. Applications include quark matter, nuclei, neutron stars and the

high temperature superconductors. Spin up and down fermions are, in principle,

inequivalent, and a normal fluid component coexists with the superfluid one. A

wider class of Hamiltonians than sheer Bardeen-Cooper-Schrieffer (BCS) type,

comprising hybridization and interaction between different fermion species, can

be treated exactly, as in the well known manner of BCS theory. A simple model

of interacting electrons in a lattice yields a ratio of the maximum

superconducting gap to the transition temperature in the range 3 to 6, as

compared to the typical isotropic s-wave BCS value of 1.76. However, the BCS

solutions are dominant for this simple model.

\\ ( http://arxiv.org/abs/0901.2487 , 301kb)

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arXiv:0901.2496

Date: Fri, 16 Jan 2009 14:42:34 GMT (143kb)

Title: Four lectures on computational statistical physics

Authors: Werner Krauth

Categories: cond-mat.stat-mech

Comments: 32 pages, Lectures given at the 2008 Les Houches Summer School "Exact

methods in low-dimensional physics and quantum computing"

\\

In my lectures at the Les Houches Summer School 2008, I discussed central

concepts of computational statistical physics, which I felt would be accessible

to the very cross-cultural audience at the school.

I started with a discussion of sampling, which lies at the heart of the Monte

Carlo approach. I specially emphasized the concept of perfect sampling, which

offers a synthesis of the traditional direct and Markov-chain sampling

approaches. The second lecture concerned classical hard-sphere systems, which

illuminate the foundations of statistical mechanics, but also illustrate the

curious difficulties that beset even the most recent simulations. I then moved

on, in the third lecture, to quantum Monte Carlo methods, that underly much of

the modern work in bosonic systems. Quantum Monte Carlo is an intricate

subject. Yet one can discuss it in simplified settings (the single-particle

free propagator, ideal bosons) and write direct-sampling algorithms for the two

cases in two or three dozen lines of code only. These idealized algorithms

illustrate many of the crucial ideas in the field. The fourth lecture attempted

to illustrate aspects of the unity of physics as realized in the Ising model

simulations of recent years.

More details on what I discussed in Les Houches, and wrote up (and somewhat

rearranged) here, can be found in my book, "Statistical Mechanics: Algorithms

and Computations", as well as in recent papers. Computer programs are available

for download and perusal at the book's web site www.smac.lps.ens.fr.

\\ ( http://arxiv.org/abs/0901.2496 , 143kb)

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arXiv:0901.2512

Date: Fri, 16 Jan 2009 16:03:09 GMT (73kb)

Title: Correlations in a two-dimensional Bose gas with long range interactions

Authors: B. Laikhtman and R. Rapaport

Categories: cond-mat.stat-mech

Comments: 11 pages including 2 figures

\\

We study the correlations of two-dimensional dipolar excitons in coupled

quantum wells with a dipole -- dipole repulsive interaction. We show that at

low concentrations, the Bose degeneracy of the excitons is accompanied by

strong multi-particle correlations and the system behaves as a Bose liquid. At

high concentration the particles interaction suppresses quantum coherence and

the system behaves similar to a classical liquid down to a temperature lower

than typical for a Bose gas. We evaluate the interaction energy per particle

and the resulting blue shift of the exciton luminescence that is a direct tool

to measure the correlations. This theory can apply to other systems of bosons

with extended interaction.

\\ ( http://arxiv.org/abs/0901.2512 , 73kb)

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arXiv:0901.2553

Date: Fri, 16 Jan 2009 19:21:37 GMT (11kb)

Title: The peculiarities of Bose-condensation of quasiparticles

Authors: A.I. Bugrij and V.M. Loktev

Categories: cond-mat.stat-mech

Comments: 10 pages

\\

An attempt is made to consider the difference between the proccesses of the

Bose-Einstein condensation of particles and quasiparticles. An equation for

particle number of the Bose-condensate as a function of the total number of

particles in the system is obtained. This equation is also written for the

caseof quasiparticles with taking into account their creation by pumping and

the existence ofequilibriumthermal excitations in the system. From the analysis

of both these equations the chemical potential of pumped quasiparticles and

their number in the condensate as a function of pumping intensity is found. It

is shown that for low energy quasiparticles the proccess of Bose-condensation

begins and proceeds at arbitrary temperatures high enough included.

\\ ( http://arxiv.org/abs/0901.2553 , 11kb)

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arXiv:0901.2549

Date: Fri, 16 Jan 2009 19:10:09 GMT (279kb)

Title: Atom trapping in an interferometrically generated bottle beam trap

Authors: L. Isenhower, W. Williams, A. Dally, and M. Saffman

Categories: physics.optics physics.atom-ph

Comments: 3 figures

\\

We demonstrate an optical bottle beam trap created by interfering two

fundamental Gaussian beams with different waists. The beams are derived from a

single laser source using a Mach-Zehnder interferometer whose arms have unequal

magnifications. Destructive interference of the two beams from the Mach-Zehnder

leads to a three dimensional intensity null at the mutual focus of the beams.

We demonstrate trapping of cold Cesium atoms in a blue detuned bottle beam

trap.

\\ ( http://arxiv.org/abs/0901.2549 , 279kb)

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arXiv:0901.2576

Date: Fri, 16 Jan 2009 21:14:04 GMT (329kb)

Title: Two-dimensional fermionic superfluids, pairing instability and vortex

liquids in the absence of time reversal symmetry

Authors: Predrag Nikolic

Categories: cond-mat.supr-con cond-mat.str-el

Comments: 11 pages, 3 figures

\\

We consider a generic two-dimensional system of fermionic particles with

attractive interactions and no disorder. If time-reversal symmetry is absent,

it is possible to obtain incompressible insulating states in addition to the

superfluid at zero temperature. The superfluid-insulator phase transition is

found to be second order in type-II systems using a perturbative analysis of

Cooper pairing instability in quantum Hall states of unpaired fermions. We

obtain the pairing phase diagram as a function of chemical potential (density)

and temperature. However, a more careful analysis presented here reveals that

the pairing quantum phase transition is always preempted by another transition

into a strongly correlated normal state which retains Cooper pairing and cannot

be smoothly connected to the quantum Hall state of unpaired fermions. Such a

normal phase can be qualitatively viewed as a liquid of vortices, although it

may acquire conventional broken symmetries. Even if it did not survive at

finite temperatures its influence would be felt through strong quantum

fluctuations below a crossover temperature scale. These conclusions directly

apply to fermionic ultra-cold atom systems near unitarity, but are likely

relevant for the properties of other strongly correlated superfluids as well,

including high temperature superconductors.

\\ ( http://arxiv.org/abs/0901.2576 , 329kb)

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arXiv:0901.2755

Date: Mon, 19 Jan 2009 19:59:23 GMT (451kb)

Title: Scale invariant thermodynamics of a toroidally trapped Bose gas

Authors: A. S. Bradley

Categories: cond-mat.stat-mech

Comments: 9 pages, 3 figures, APS format

\\

We consider a system of bosonic atoms in an axially symmetric harmonic trap

augmented with a Gaussian optical potential. Focussing on the case of blue

detuning we determine the ideal gas thermodynamics of the system for

configurations ranging from the harmonic trap to the toroidal regime. For large

tori the ideal gas thermodynamics of the system are found to be independent of

toroidal radius. In considering corrections to the scale invariant transition

temperature, we find that the first order interaction shift is the dominant

effect in the thermodynamic limit, and is also scale invariant. We also

consider adiabatic loading from the harmonic to toroidal trap configuration,

which we show to have only a small effect on the condensate fraction for the

ideal gas, indicating that loading into the scale invariant regime may be

experimentally practical.

\\ ( http://arxiv.org/abs/0901.2755 , 451kb)

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arXiv:0901.2807

Date: Mon, 19 Jan 2009 10:41:27 GMT (444kb)

Title: Occupation Statistics of a BEC for a Driven Landau-Zener Crossing

Authors: Katrina Smith-Mannschott, Maya Chuchem, Moritz Hiller, Tsampikos

Kottos, Doron Cohen

Categories: cond-mat.other

Comments: 4 pages, 5 figures

\\

We consider an atomic Bose-Einstein condensate (BEC) loaded in a biased

double-well trap with tunneling rate $K$ and inter-atomic interaction $U$. The

BEC is prepared such that all $N$ atoms are in the left well. We drive the

system by sweeping the potential difference $\epsilon$ between the two wells.

Depending on the interaction $u=NU/K$, and the sweep rate $\dot{\epsilon}$, we

distinguish three dynamical regimes: {\em adiabatic}, {\em diabatic}, and {\em

sudden} and consider the occupation statistics of the final state. The analysis

goes beyond mean-field theory and is complemented by a semiclassical picture.

\\ ( http://arxiv.org/abs/0901.2807 , 444kb)

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arXiv:0901.2836

Date: Mon, 19 Jan 2009 12:40:17 GMT (9kb)

Title: Entanglement generation by collisions of quantum solitons

Authors: Maciej Lewenstein and Boris A. Malomed

Categories: cond-mat.other

\\

We present general analytic expressions describing generation of the

entanglement in collisions of initially uncorrelated quantum solitons. The

results, obtained by means of the Born approximation, are valid for both

integrable and non-integrable quasi-one-dimensional systems supporting soliton

states.

\\ ( http://arxiv.org/abs/0901.2836 , 9kb)

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arXiv:0901.2842

Date: Mon, 19 Jan 2009 13:00:57 GMT (636kb)

Title: Chandrasekhar-Clogston limit and phase separation in Fermi mixtures at

Unitarity

Authors: I. Bausmerth, A. Recati and S. Stringari

Categories: cond-mat.other

Comments: 7 pages, 6 figures

\\

Using many-body results available from diagrammatic and {\it ab initio} Monte

Carlo calculations we analyze the phase diagram $\mu=(\mua+\mda)/2$ versus

$h=(\mua-\mda)/2$ of a unitary Fermi gas at zero temperature with population

imbalance and unequal masses. We identify different regions where the gas is

superfluid, partially polarized or fully polarized and determine the

corresponding coexistence conditions. The asymmetry in the phase diagram,

caused by the mass imbalance, and its effect on the Chandrasekhar-Clogston

limit for the critical polarization are explicitly discussed. The equation of

state of the superfluid and normal phases is employed, within the local density

approximation, to predict novel phase separated configurations in the presence

of harmonic trapping potentials.

\\ ( http://arxiv.org/abs/0901.2842 , 636kb)

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arXiv:0901.2890

Date: Mon, 19 Jan 2009 16:30:04 GMT (448kb)

Title: Manipulation of quantum particles in rapidly oscillating potentials by

inducing phase hops

Authors: Armin Ridinger (LKB - Lhomond), Christoph Weiss (LKB - Lhomond)

Categories: cond-mat.other quant-ph

Comments: 7 pages, 4 figures

Journal-ref: Physical Review A: Atomic, Molecular and Optical Physics 79, 1

(2009) 013414

DOI: 10.1103/PhysRevA.79.013414

\\

Analytical calculations show that the mean-motion of a quantum particle

trapped by a rapidly oscillating potential can be significantly manipulated by

inducing phase hops, i.e., by instantaneously changing the potential's phase. A

phase hop can be visualized as being the result of a collision with an

imaginary particle which can be controlled. Several phase hops can have

accumulating effects on the particle's mean-motion, even if they transform the

particle's Hamiltonian into its initial one. The theoretical predictions are

verified by numerical simulations for the one-dimensional Paul-trap.

\\ ( http://arxiv.org/abs/0901.2890 , 448kb)

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arXiv:0901.2783

Date: Mon, 19 Jan 2009 08:44:18 GMT (2231kb,D)

Title: Continuous Variable Entanglement and Squeezing of Orbital Angular

Momentum States

Authors: Mikael Lassen, Gerd Leuchs, Ulrik L. Andersen

Categories: quant-ph

Comments: 4 pages, 4 figures

\\

We report the first experimental characterization of the first-order

continuous variable orbital angular momentum states. Using a spatially

non-degenerate optical parametric oscillator (OPO) we produce quadrature

entanglement between the two first-order Laguerre-Gauss modes. The family of

OAM modes is mapped on an orbital Poincare sphere, and the modes position on

the sphere is spanned by the three orbital parameters. Using the non-degenerate

OPO we produce squeezing of these parameters, and as an illustration, we

reconstruct the "cigar-shaped" uncertainty volume on the orbital Poincare

sphere.

\\ ( http://arxiv.org/abs/0901.2783 , 2231kb)

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arXiv:0901.2943

Date: Mon, 19 Jan 2009 22:08:28 GMT (25kb,D)

Title: Ground state energy of the two-dimensional weakly interacting Bose gas:

First correction beyond Bogoliubov theory

Authors: Christophe Mora, Yvan Castin

Categories: cond-mat.stat-mech

Comments: 4 pages, 1 figure

\\

We consider the grand potential $\Omega$ of a two-dimensional weakly

interacting homogeneous Bose gas at zero temperature. Building on a

number-conserving Bogoliubov method for a lattice model in the grand canonical

ensemble, we calculate the next order term as compared to the Bogoliubov

prediction, in a systematic expansion of $\Omega$ in powers of the parameter

measuring the weakness of the interaction. Our prediction is in very good

agreement with recent Monte Carlo calculations.

\\ ( http://arxiv.org/abs/0901.2943 , 25kb)

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arXiv:0901.2945

Date: Mon, 19 Jan 2009 22:22:51 GMT (753kb)

Title: Theory of the Normal/Superfluid interface in population imbalanced Fermi

gases

Authors: Stefan K. Baur (Cornell), Sourish Basu (Cornell), Theja N. De Silva

(Binghamton), Erich J. Mueller (Cornell)

Categories: cond-mat.other

Comments: 15 pages, 9 figures (13 subfigures)

\\

We present a series of theoretical studies of the boundary between a

superfluid and normal region in a partially polarized gas of strongly

interacting fermions. We present mean-field estimates of the surface energy in

this boundary as a function of temperature and scattering length. We discuss

the structure of the domain wall, and use a previously introduced

phenomonological model to study its influence on experimental observables.

\\ ( http://arxiv.org/abs/0901.2945 , 753kb)

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arXiv:0901.3048

Date: Tue, 20 Jan 2009 12:56:09 GMT (25kb)

Title: Weakly Interacting Bose Mixtures at Finite Temperature

Authors: Bert Van Schaeybroeck

Categories: cond-mat.other cond-mat.stat-mech

Comments: 4 pages, 2 figures

\\

Motivated by the recent experiments on Bose-Einstein mixtures with tunable

interactions we study repulsive weakly interacting Bose mixtures at finite

temperature. We obtain phase diagrams using Hartree-Fock theory which are

directly applicable to experimentally trapped systems. Almost all features of

the diagrams can be characterized using simple physical insights. Our work

reveals two surprising effects which are dissimilar to a system at zero

temperature. First of all, no pure phases exist, that is, at each point in the

trap, particles of both species are always present. Second, even for very weak

interspecies repulsion when full mixing is expected, condensate particles of

both species may be present in a trap without them being mixed.

\\ ( http://arxiv.org/abs/0901.3048 , 25kb)

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arXiv:0901.3091

Date: Tue, 20 Jan 2009 16:35:09 GMT (178kb)

Title: Quantum polarization spectroscopy of correlations in attractive

fermionic gases

Authors: T. Roscilde, M. Rodriguez, K. Eckert, O. Romero-Isart, M. Lewenstein,

E. Polzik and A. Sanpera

Categories: cond-mat.str-el cond-mat.mes-hall

Comments: 16 pages, 9 figures

\\

We show how spin-spin correlations, detected in a non-destructive way via

spatially resolved quantum polarization spectroscopy, strongly characterize

various phases realized in trapped ultracold fermionic atoms. Polarization

degrees of freedom of the light couple to spatially resolved components of the

atomic spin. In this way quantum fluctuations of matter are faithfully mapped

onto those of light. In particular we demonstrate that quantum spin

polarization spectroscopy provides a direct method to detect the

Fulde-Ferrell-Larkin-Ovchinnikov phase realized in a one-dimensional imbalanced

Fermi system.

\\ ( http://arxiv.org/abs/0901.3091 , 178kb)

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arXiv:0901.2956

Date: Mon, 19 Jan 2009 23:45:33 GMT (72kb)

Title: Synchronous Quantum Memories with Time-symmetric Pulses

Authors: Q. Y. He, M. D. Reid, and P. D. Drummond

Categories: quant-ph

Comments: 4 pages, 4 figures

\\

We propose a dynamical approach to quantum memories using a synchronous

oscillator-cavity model, in which the coupling is shaped in time to provide the

optimum interface to a symmetric input pulse. This overcomes the known

difficulties of achieving high quantum input-output fidelity with storage times

long compared to the input signal duration. Our generic model is applicable to

any linear storage medium ranging from a superconducting device to an atomic

medium. We show that with temporal modulation of coupling and/or detuning, it

is possible to mode-match to time-symmetric pulses that have identical pulse

shapes on input and output.

\\ ( http://arxiv.org/abs/0901.2956 , 72kb)

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arXiv:0901.3105

Date: Tue, 20 Jan 2009 17:44:22 GMT (495kb)

Title: Prospects for a mHz-linewidth laser

Authors: D. Meiser, Jun Ye, D. R. Carlson, and M. J. Holland

Categories: quant-ph

Comments: 5 pages, 3 figures

\\

Optical atomic clocks based on ultracold alkaline-earth atoms confined in a

lattice potential are competitive with the most stable and accurate time and

frequency standards. The main bottleneck that prevents these clocks from

achieving still better precision is the linewidth of the laser used to

interrogate the clock transition. We propose to utilize the ultra-narrow atomic

transition by making the atoms emit photons on that line collectively into the

mode of a high Q-resonator in a laser-like fashion. A power level of order

$10^{-12}$ W is possible, sufficient for phase-locking a slave optical local

oscillator. We find that the linewidth of the radiation can be on the order of

or even narrower than that of the clock transition due to collective effects.

Achieving this major breakthrough will improve the stability of the best clocks

by two orders of magnitude.

\\ ( http://arxiv.org/abs/0901.3105 , 495kb)

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arXiv:0901.3129

Date: Tue, 20 Jan 2009 19:52:15 GMT (116kb)

Title: Feshbach resonances in ultracold atom-molecule collisions

Authors: A. Simoni, J-M. Launay, P. Soldan

Categories: quant-ph

Comments: 7 pages, 6 figures

\\

We investigate the presence of Feshbach resonances in ultracold

alkali-dialkali reactive collisions. Quantum scattering calculations are

performed on a new Na_3 quartet potential energy surface. An analysis of

scattering features is performed through a systematic variation of the

nonadditive three-body interaction potential. Our results should provide useful

information for interpreting future atom-molecule collision experiments.

\\ ( http://arxiv.org/abs/0901.3129 , 116kb)

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arXiv:0901.2960

Date: Mon, 19 Jan 2009 23:59:00 GMT (1533kb)

Title: Two-Photon Dichroic Atomic Vapor Laser Lock Using Electromagnetically

Induced Transparency and Absorption

Authors: F. E. Becerra, R. T. Willis, S. L. Rolston, L. A. Orozco

Categories: physics.optics physics.atom-ph

Comments: 6 pages, 8 figures

\\

We demonstrate a technique to lock the frequency of a laser to a two-photon

transition of Rb vapor in the presence of a weak magnetic field. We use a

ladder configuration from specific hyperfine sublevels of the 5S 1/2, 5P 3/2,

and 5D 5/2 levels. This transition shows Electromagnetically Induced

Transparency and Absorption processes. The error signal comes from the

difference in the transparency or absorption felt by the two orthogonal

polarizations of the probe beam. A simplified model is in good quantitative

agreement with the observed signals for the experimental parameters. We have

used this technique to lock the frequency of the laser up to 1.5 GHz off atomic

resonance.

\\ ( http://arxiv.org/abs/0901.2960 , 1533kb)

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arXiv:0901.3148

Date: Tue, 20 Jan 2009 21:07:29 GMT (112kb)

Title: Heavy-Light Fermion Mixtures at Unitarity

Authors: Alexandros Gezerlis, S. Gandolfi, K. E. Schmidt, J. Carlson

Categories: cond-mat.other

Comments: 4 pages, 4 figures

\\

We investigate pairing between unequal-mass fermions in the unitary regime

for a mass ratio corresponding to a 6Li-40K mixture. We show that the fully

paired superfluid state is nearly independent of the mass ratio; the

ground-state energy and the average light and heavy particle excitation

spectrum change very little. However, in the majority light system, the

polarized superfluid is close to stability compared to a phase separated state.

For a majority of heavy particles, we find an energy minimum for a normal state

with a ratio of ~ 3:1 heavy to light particles. A slight increase in attraction

to kF*a ~ 2.5 renders the system unstable. A cold unpolarized system in a

harmonic trap at unitarity should phase separate into three regions: a normal

state with a large heavy to light ratio in the center, followed by a shell of

fully paired superfluid in the middle and either a polarized superfluid or a

nearly fully polarized normal state in the exterior.

\\ ( http://arxiv.org/abs/0901.3148 , 112kb)

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arXiv:0901.3152

Date: Tue, 20 Jan 2009 21:26:06 GMT (142kb)

Title: Phase-imprint induced domain formations and spin dynamics in spinor

condensates

Authors: Chengjun Tao and Qiang Gu

Categories: cond-mat.other cond-mat.supr-con

Comments: 5 pages, 5 figures, to appear in Phys. Rev. A

\\

We demonstrate that certain domain structures can be created both in ferro-

and antiferro-magnetic spinor condensates if the initial phase is spatially

modulated. Meanwhile, spin dynamics of the condensate with modulated phases

exhibits exotic features in comparison with those of a condensate with a

uniform phase. We expect that these phenomena could be observed experimentally

using a phase-imprinting method.

\\ ( http://arxiv.org/abs/0901.3152 , 142kb)

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arXiv:0901.3285

Date: Wed, 21 Jan 2009 14:45:36 GMT (393kb)

Title: Population imbalanced Fermi gases in quasi two dimensions

Authors: Theja N. De Silva

Categories: cond-mat.other

Comments: 6 pages and 5 figures

\\

We study population imbalanced Fermi gases in quasi two dimensions using a

mean field theory. At zero temperature, we derive an analytic equation for the

gap parameter together with analytical expressions for the free energy and

density for weakly coupled layers in the entire Bardeen, Cooper and

Schrieffer-Bose Einstein condensation (BCS-BEC) crossover region. By

investigating the effect of weak atom tunneling between layers, we then map out

the phase diagram of the system. We find that the superfluid phase stabilizes

as one decreases the atom tunneling between layers. This allows one to control

the first order superfluid-normal phase transition by tuning a single

experimental parameter. At Finite temperatures, we use a Landau-Ginzberg

functional approach to investigate the possibility of spatially inhomogeneous

Fulde-Ferrel-Larkin-Ovchinnikov (FFLO) phase in the weak coupling BCS limit

near the tricritical point of spatially homogenous superfluid, FFLO, and normal

phases. We find that the normal-FFLO phase transition is first order as oppose

to the zero temperature theories.

\\ ( http://arxiv.org/abs/0901.3285 , 393kb)

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arXiv:0901.3345

Date: Wed, 21 Jan 2009 20:50:35 GMT (470kb)

Title: Quantum dynamics of instability-induced pulsations of a Bose-Einstein

condensate in an optical lattice

Authors: Uttam Shrestha, Juha Javanainen, and Janne Ruostekoski

Categories: cond-mat.other

\\

We study the dynamics of a Bose-Einstein condensate in a one-dimensional

optical lattice in the limit of weak atom-atom interactions, including an

approximate model for quantum fluctuations. A pulsating dynamical instability

in which atoms periodically collect together and subsequently disperse back

into the initial homogeneous state may occur in the time evolution. We take

into account the quantum fluctuations within the truncated Wigner

approximation. We observe that the quasiperiodic behavior still persists for a

single realization that represents a typical experimental outcome, but ensemble

averages show various manifestations of quantum fluctuations. Quantum effects

become more prominent when the effective interaction strength is increased.

\\ ( http://arxiv.org/abs/0901.3345 , 470kb)

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arXiv:0901.3309

Date: Wed, 21 Jan 2009 16:38:48 GMT (399kb)

Title: Determining the Minimum Uncertainty State of Nonclassical Light

Authors: C. Gabriel, J. Janousek, and H.-A. Bachor

Categories: quant-ph

\\

Squeezing experiments which are capable of creating a minimum uncertainty

state during the nonlinear process, for example optical parametric

amplification, are commonly used to produce light far below the quantum noise

limit. This report presents a method with which one can characterize this

minimum uncertainty state and gain valuable knowledge of the experimental

setup.

\\ ( http://arxiv.org/abs/0901.3309 , 399kb)

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arXiv:0901.3335

Date: Wed, 21 Jan 2009 19:23:31 GMT (374kb)

Title: Quantum Optics with Quantum Gases

Authors: Igor B. Mekhov and Helmut Ritsch

Categories: quant-ph

Comments: to be published in Laser Physics (2009)

\\

Quantum optics with quantum gases represents a new field, where the quantum

nature of both light and ultracold matter plays equally important role. Only

very recently this ultimate quantum limit of light-matter interaction became

feasible experimentally. In traditional quantum optics, the cold atoms are

considered classically, whereas, in quantum atom optics, the light is used as

an essentially classical axillary tool. On the one hand, the quantization of

optical trapping potentials can significantly modify many-body dynamics of

atoms, which is well-known only for classical potentials. On the other hand,

atomic fluctuations can modify the properties of the scattered light.

\\ ( http://arxiv.org/abs/0901.3335 , 374kb)

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arXiv:0901.3303

Date: Wed, 21 Jan 2009 16:08:22 GMT (119kb)

Title: Atom chips and one-dimensional Bose gases

Authors: Isabelle Bouchoule (LCFIO), N. J. Van Druten, Chris Westbrook (LCFIO)

Categories: physics.atom-ph

\\

In this review article, we describe the studies of 1D gases realised on

atom-chip experiments.

\\ ( http://arxiv.org/abs/0901.3303 , 119kb)

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arXiv:0901.3438

Date: Thu, 22 Jan 2009 09:44:21 GMT (47kb)

Title: Zero Sound and First Sound in a Disk-Shaped Normal Fermi gas

Authors: Giovanni Mazzarella, Luca Salasnich, Flavio Toigo

Categories: cond-mat.other

Comments: 9 pages, 5 figures, editorially approved for publication on Phys.

Rev. A

\\

We study the zero sound and the first sound in a dilute and ultracold

disk-shaped normal Fermi gas with a strong harmonic confinement along the axial

direction and uniform in the two planar directions. Working at zero temperature

we calculate the chemical potential $\mu$ of the fermionic fluid as a function

of the uniform planar density $\rho$ and find that $\mu$ changes its slope in

correspondence to the filling of harmonic axial modes (shell effects). Within

the linear response theory, and under the random phase approximation, we

calculate the velocity $c^{0}_s$ of the zero sound. We find that also $c^0_s$

changes its slope in correspondence of the filling of the harmonic axial modes

and that this effect depends on the Fermi-Fermi scattering length $a_F$. In the

collisional regime, we calculate the velocity $c_s$ of first sound showing that

$c_s$ displays jumps at critical densities fixed by the scattering length

$a_F$. Finally, we discuss the experimental achievability of these zero sound

and first sound waves with ultracold alkali-metal atoms.

\\ ( http://arxiv.org/abs/0901.3438 , 47kb)

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\\

arXiv:0901.3439

Date: Thu, 22 Jan 2009 09:44:29 GMT (768kb)

Title: An Introduction to the Quantum Theory of Nonlinear Optics

Authors: Mark Hillery

Categories: quant-ph

Comments: 80 pages,

Journal-ref: Acta Physica Slovaca 59, No.1, 1-80 (2009)

\\

This article is provides an introduction to the quantum theory of optics in

nonlinear dielectric media. We begin with a short summary of the classical

theory of nonlinear optics, that is nonlinear optics done with classical

fields. We then discuss the canonical formalism for fields and its

quantization. This is applied to quantizing the electromagnetic field in free

space. The definition of a nonclassical state of the electromagnetic field is

presented, and several examples are examined. This is followed by a brief

introduction to entanglement in the context of field modes. The next task is

the quantization of the electromagnetic field in an inhomogeneous, linear

dielectric medium. Before going on to field quantization in nonlinear media, we

discuss a number of commonly employed phenomenological models for quantum

nonlinear optical processes. We then quantize the field in both nondispersive

and dispersive nonlinear media. Flaws in the most commonly used methods of

accomplishing this task are pointed out and discussed. Once the quantization

has been completed, it is used to study a multimode theory of parametric down

conversion and the propagation of quantum solitons.

\\ ( http://arxiv.org/abs/0901.3439 , 768kb)

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\\

arXiv:0901.3355

Date: Thu, 22 Jan 2009 19:42:34 GMT (366kb)

Title: Bose-Einstein Condensation of Electrons in Doubly Excited States of

Heliumlike Atoms

Authors: V.V.Kavera

Categories: physics.atom-ph physics.plasm-ph

Comments: 4 pages

\\

The author supposes a capability of transition doubly excited configurations

of separate atoms to a superconducting state. The conditions of this transition

are determined and the experiments for its detection are offered. The

capability of join of superconducting atoms in a superconducting condensate is

considered. The capability of spontaneous formation of similar condensates in

atmospheres of the Earth and Sun is considered.

\\ ( http://arxiv.org/abs/0901.3355 , 366kb)

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The replacements:

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\\

arXiv:0807.1450

replaced with revised version Thu, 15 Jan 2009 22:21:01 GMT (343kb)

Title: Fermionic superfluid properties in a one-dimensional optical lattice

Authors: Theja N. De Silva

Categories: cond-mat.other

Comments: 6 pages, 5 figures, Updated with the published version

Journal-ref: Phys. Rev. A 79, 013612 (2009)

DOI: 10.1103/PhysRevA.79.013612

\\ ( http://arxiv.org/abs/0807.1450 , 343kb)

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\\

arXiv:0807.3067

replaced with revised version Fri, 16 Jan 2009 16:21:31 GMT (170kb)

Title: Ultracold atom spin field effect transistors

Authors: J. Y. Vaishnav, Julius Ruseckas, Charles W. Clark, Gediminas

Juzeliunas

Categories: cond-mat.mes-hall cond-mat.other physics.atom-ph quant-ph

Journal-ref: Phys. Rev. Lett. 101, 265302 (2008)

DOI: 10.1103/PhysRevLett.101.265302

\\ ( http://arxiv.org/abs/0807.3067 , 170kb)

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\\

arXiv:0802.1222

replaced with revised version Thu, 15 Jan 2009 22:21:13 GMT (31kb)

Title: S-wave and p-wave scattering in a cold gas of Na and Rb atoms

Authors: Henni Ouerdane and Michael J. Jamieson

Categories: physics.atom-ph

Comments: The article contains additional material and data (see abstract)

\\ ( http://arxiv.org/abs/0802.1222 , 31kb)

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\\

arXiv:0805.2571

replaced with revised version Sat, 17 Jan 2009 15:44:29 GMT (741kb)

Title: Superfluid Bose gas in two dimensions

Authors: S. Floerchinger and C. Wetterich

Categories: cond-mat.supr-con

Comments: 10 pages, 12 figures, reference added

Journal-ref: Phys. Rev. A 79, 013601 (2009)

DOI: 10.1103/PhysRevA.79.013601

\\ ( http://arxiv.org/abs/0805.2571 , 741kb)

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\\

arXiv:0809.1675

replaced with revised version Sat, 17 Jan 2009 15:53:43 GMT (314kb)

Title: Functional renormalization for trion formation in ultracold fermion

gases

Authors: S. Floerchinger, R. Schmidt, S. Moroz, and C. Wetterich

Categories: cond-mat.supr-con

Comments: 9 pages, 4 figures, minor changes, reference added

Journal-ref: Phys. Rev. A 79, 013603 (2009)

DOI: 10.1103/PhysRevA.79.013603

\\ ( http://arxiv.org/abs/0809.1675 , 314kb)

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\\

arXiv:0806.2812

replaced with revised version Tue, 20 Jan 2009 16:35:18 GMT (121kb)

Title: Quantum Phase Diagram of Bosons in Optical Lattices

Authors: F. E. A. dos Santos and A. Pelster

Categories: cond-mat.stat-mech

Journal-ref: Physical Review A 79, 013614 (2009)

\\ ( http://arxiv.org/abs/0806.2812 , 121kb)

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arXiv:0712.2951

replaced with revised version Thu, 22 Jan 2009 06:14:32 GMT (569kb)

Title: Discrete chaotic states of a Bose-Einstein condensate

Authors: Wenhua Hai, Shiguang Rong, Qianquan Zhu

Categories: cond-mat.other

Comments: 7 pages, 5 figures

Journal-ref: Phys. Rev. E 78, 066214 (2008)

\\ ( http://arxiv.org/abs/0712.2951 , 569kb)

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\\

arXiv:0808.1898

replaced with revised version Thu, 22 Jan 2009 20:27:22 GMT (161kb)

Title: Phonon-induced artificial magnetic fields

Authors: Alexander Klein and Dieter Jaksch

Categories: quant-ph cond-mat.other

Comments: 6 pages, 4 figures

Journal-ref: EPL, 85 (2009) 13001

DOI: 10.1209/0295-5075/85/13001

\\ ( http://arxiv.org/abs/0808.1898 , 161kb)

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\\

arXiv:0810.2028

replaced with revised version Thu, 22 Jan 2009 20:42:12 GMT (2338kb)

Title: Structure formation during the collapse of a dipolar atomic

Bose-Einstein condensate

Authors: N.G. Parker, C. Ticknor, A.M. Martin and D.H.J. O'Dell

Categories: cond-mat.other

Comments: In this version (the published version) we have slightly rewritten

the manuscript in places and have corrected some typos. 15 pages and 13

figures

Journal-ref: N. G. Parker, C. Ticknor, A. M. Martin and D. H. J. O'Dell, Phys.

Rev. A 79, 013617 (2009)

\\ ( http://arxiv.org/abs/0810.2028 , 2338kb)

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Till next time,

Matt.

-- ========================================================================= Dr M. J. Davis, Associate Professor in Physics School of Mathematics and Physics, ph : +61 7 334 69824 The University of Queensland, fax : +61 7 336 51242 Brisbane, QLD 4072, mdavis_at_physics.uq.edu.au Australia. 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 Fri May 01 2009 - 15:51:04 EST

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