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

Date: Mon, 14 Jul 2008 09:16:35 +1000

Date: Mon, 14 Jul 2008 09:16:35 +1000

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

Dear all,

This week there were 25 new preprints and 11 replacements:

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arXiv:0806.4431

Date: Fri, 27 Jun 2008 06:38:41 GMT (8kb)

Title: Dephasing in two decoupled one-dimensional Bose-Einstein condensates and

the subexponential decay of the interwell coherence

Authors: I.E. Mazets, J. Schmiedmayer

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

Comments: revtex4, no figures

\\

We provide a simple physical picture of the loss of coherence between two

coherently split one-dimensional Bose-Einstein condensates. The source of the

dephasing is identified with nonlinear corrections to the elementary excitation

energies in either of the two independent condensates. We retrieve the result

by Burkov, Lukin and Demler [Phys. Rev. Lett. 98, 200404 (2007)] on the

subexponential decay of the cocherence for the large time, however, the scaling

of the characteristic decoherence time differs.

\\ ( http://arxiv.org/abs/0806.4431 , 8kb)

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arXiv:0806.4713

Date: Sat, 28 Jun 2008 18:02:10 GMT (28kb)

Title: Equation of state and effective mass of the unitary Fermi gas in a 1D

periodic potential

Authors: Gentaro Watanabe, Giuliano Orso, Franco Dalfovo, Lev P. Pitaevskii,

Sandro Stringari

Categories: cond-mat.supr-con

Comments: 4 pages, 3 figures

\\

We study the behavior of a superfluid Fermi gas at unitarity in a 1D optical

lattice by solving the Bogoliubov-de Gennes equations at zero temperature. We

show that the tendency of the lattice to favor the formation of molecules

results in a significant increase of both the effective mass and the

compressibility at low densities, with a consequent large reduction of the

sound velocity. At higher density, when the interparticle distance becomes of

the order of the lattice period, the effective mass reaches its maximum value

and the system becomes less compressible. Predictions for the frequency of the

collective oscillations in the presence of harmonic trapping are also given.

\\ ( http://arxiv.org/abs/0806.4713 , 28kb)

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arXiv:0806.4784

Date: Sun, 29 Jun 2008 20:30:02 GMT (540kb)

Title: Interacting atoms in optical lattices

Authors: Johan Mentink and Servaas Kokkelmans

Categories: cond-mat.other

Comments: 7 pages, 4 figures

\\

We propose an easy to use model to solve for interacting atoms in an optical

lattice. This model allows for the whole range of weakly to strongly

interacting atoms, and it includes the coupling between relative and

center-of-mass motion via anharmonic lattice terms. We apply this model to a

high-precision spin dynamics experiment, and we discuss the corrections due to

atomic interactions and the anharmonic coupling. Under suitable experimental

conditions, energy can be transferred between the relative and center-of-mass

motion, and this allows for creation of Feshbach molecules in excited lattice

bands.

\\ ( http://arxiv.org/abs/0806.4784 , 540kb)

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arXiv:0806.4895

Date: Mon, 30 Jun 2008 14:54:05 GMT (8kb)

Title: Collective Excitations of Harmonically Trapped Ideal Gases

Authors: Bert Van Schaeybroeck, Achilleas Lazarides

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

Comments: 4 pages, submitted to special issue of Eur. Phys. J. B "Novel Quantum

Phases and Mesoscopic Physics in Quantum Gases"

\\

We theoretically study the collective excitations of an ideal gas confined in

an isotropic harmonic trap. We give an exact solution to the Boltzmann-Vlasov

equation; as expected for a single-component system, the associated mode

frequencies are integer multiples of the trapping frequency. We show that the

expressions found by the scaling ansatz method are a special case of our

solution. Our findings, however, are most useful in case the trap contains more

than one phase: we demonstrate how to obtain the oscillation frequencies in

case an interface is present between the ideal gas and a different phase.

\\ ( http://arxiv.org/abs/0806.4895 , 8kb)

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arXiv:0806.4961

Date: Mon, 30 Jun 2008 18:14:25 GMT (121kb)

Title: Spectral signatures of the FFLO order parameter in one-dimensional

optical lattices

Authors: M.R. Bakhtiari, M.J. Leskinen, P. Torma

Categories: cond-mat.other

Comments: 5 pages, 5 figures

\\

We address an imbalanced two-component atomic Fermi gas restricted by a

one-dimensional (1D) optical lattice and an external harmonic potential, within

the mean-field Bogoliubov-de Gennes (BdG) formalism. We show that

characteristic features of the Fulde-Ferrel-Larkin-Ovchinnikov (FFLO) state are

visible in the RF-spectra and in the momentum resolved photoemission spectra of

the gas. Especially, Andreev states or mid-gap states can be clearly resolved,

which gives a direct experimentally observable signature of the oscillating

order parameter.

\\ ( http://arxiv.org/abs/0806.4961 , 121kb)

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arXiv:0806.4337 (*cross-listing*)

Date: Thu, 26 Jun 2008 15:17:37 GMT (1776kb)

Title: Low-density, one dimensional quantum gases in the presence of a

localised attractive potential

Authors: J. Goold, D. O Donoghue and Th. Busch

Categories: quant-ph cond-mat.mes-hall

Comments: 15 pages, 9 figures

\\

We investigate low-density, quantum-degenerate gases in the presence of a

localised attractive potential in the centre of a one-dimensional harmonic

trap.The attractive potential is modelled using a parameterised delta-function,

allowing us to determine all single particle eigenfunctions analytically. From

these we calculate the ground state many-body properties for a system of

spin-polarised fermions and, using the Bose-Fermi mapping theorem, extend the

results to strongly interacting bosonic systems. We discuss the single particle

densities, the pair correlation functions, the reduced single particle density

matrices and the momentum distributions as a function of particle number and

strength of the attractive point potential. As an important experimental

observable, we place special emphasis on spatial coherence properties of such

samples.

\\ ( http://arxiv.org/abs/0806.4337 , 1776kb)

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arXiv:0806.4893

Date: Mon, 30 Jun 2008 13:51:29 GMT (713kb)

Title: Role of the Mean-field in Bloch Oscillations of a Bose-Einstein

Condensate in an Optical Lattice and Harmonic Trap

Authors: R. Zhang, R. E. Sapiro, R. R. Mhaskar, G. Raithel

Categories: physics.atom-ph cond-mat.other

Comments: BEC simulation, 7 figures

\\

Using the Crank-Nicholson method, we study the evolution of a Bose-Einstein

condensate in an optical lattice and harmonic trap. The condensate is excited

by displacing it from the center of the harmonic trap. The mean field plays an

important role in the Bloch-like oscillations that occur after sufficiently

large initial displacement. We find that a moderate mean field significantly

suppresses the dispersion of the condensate in momentum space. When the mean

field becomes large, soliton and vortex structures appear in the condensate

wavefunction.

\\ ( http://arxiv.org/abs/0806.4893 , 713kb)

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arXiv:0806.4847

Date: Mon, 30 Jun 2008 10:36:30 GMT (449kb)

Title: Quantum reflection of helium atom beams from a microstructured grating

Authors: Bum Suk Zhao, Stephan A. Schulz, Samuel A. Meek, Gerard Meijer, and

Wieland Sch\"ollkopf

Categories: physics.atom-ph

Comments: 4 pages, 4 figures

\\

We observe high-resolution diffraction patterns of a thermal-energy

helium-atom beam reflected from a microstructured surface grating at grazing

incidence. The grating consists of 10-$\mu$m-wide Cr strips patterned on a

quartz substrate and has a periodicity of 20 $\mu$m. Fully-resolved diffraction

peaks up to the $7^{\rm th}$ order are observed at grazing angles up to 20

mrad. With changes in de Broglie wavelength or grazing angle the relative

diffraction intensities show significant variations which shed light on the

nature of the atom-surface interaction potential. The observations are

explained in terms of quantum reflection at the long-range attractive

Casimir-van der Waals potential.

\\ ( http://arxiv.org/abs/0806.4847 , 449kb)

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arXiv:0807.0002

Date: Mon, 30 Jun 2008 20:00:14 GMT (19kb)

Title: Superfluidity near phase separation in Bose-Fermi mixtures

Authors: Tilman Enss, Wilhelm Zwerger

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

Comments: 5 pages and 3 figures

\\

We study the transition to fermion pair superfluidity in a mixture of

interacting bosonic and fermionic atoms. The fermion interaction induced by the

bosons and the dynamical screening of the condensate phonons due to fermions

are included using the nonperturbative Hamiltonian flow equations. We determine

the bosonic spectrum near the transition towards phase separation and find that

the superfluid transition temperature may be increased substantially due to

phonon damping.

\\ ( http://arxiv.org/abs/0807.0002 , 19kb)

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arXiv:0807.0018

Date: Mon, 30 Jun 2008 21:08:54 GMT (15kb)

Title: Spin Collective Modes of Two-Species Fermi Liquids: Helium-3 and Atomic

Gases near the Feshbach Resonance

Authors: H. P. Dahal, S. Gaudio, J. D. Feldmann, K. S. Bedell

Categories: cond-mat.other

Comments: 4 pages, 4 figures

\\

We present theoretical findings on the spin collective modes of a two-species

Fermi liquid, prepared alternatively in a polarized equilibrium or a polarized

non-equilibrium state. We explore the effects on these modes of a diverging

s-wave scattering length, as occurs near a Feshbach resonance in a Fermionic

atomic gas. We compare these atomic gas modes with those of the conventional

Helium-3 system, and we find that they differ from the conventional systems,

and that the gap and spin stiffness are tunable via the Feshbach resonance.

\\ ( http://arxiv.org/abs/0807.0018 , 15kb)

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arXiv:0807.0031

Date: Mon, 30 Jun 2008 22:13:10 GMT (522kb)

Title: Tunneling electro-conductance of atomic Bose condensates

Authors: V. M. Akulin, Yu. E. Lozzovik, I. E. Mazets, A. G. Rudavets, A.

Sarfati

Categories: cond-mat.mes-hall

Comments: 26 pages, 12 figures

\\

We consider interaction of an electron with a Bose condensate of atoms having

electron affinity. Though states of the electron attached to atoms form a

continuous band, tunneling through this band is strongly suppressed by quantum

fluctuations of the condensate density. We adapt standard field theory methods

originally developed for description of a particle propagating trough a

disordered potential and present an exactly soluble analytical model of the

process. In contrast with the standard description, we take into account

inelastic processes associated with quantum transitions in the condensate.

Possibilities of the experimental observation of the phenomenon are discussed.

\\ ( http://arxiv.org/abs/0807.0031 , 522kb)

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arXiv:0807.0078

Date: Tue, 1 Jul 2008 08:11:10 GMT (57kb)

Title: Number of closed-channel molecules in the BEC-BCS crossover

Authors: Felix Werner (LKB - Lhomond), Leticia Tarruell (LKB - Lhomond), Yvan

Castin (LKB - Lhomond)

Categories: cond-mat.other

\\

Using a two-channel model, we show that the number of closed channel

molecules in a two-component Fermi gas close to a Feshbach resonance is

directly related to the derivative of the energy of the gas with respect to the

inverse scattering length. We extract this quantity from the fixed node

Monte-Carlo equation of state and we compare to the number of closed channel

molecules measured in the Rice experiment with lithium [Partridge et al., Phys.

Rev. Lett. 95, 020404 (2005)].

\\ ( http://arxiv.org/abs/0807.0078 , 57kb)

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arXiv:0807.0067

Date: Tue, 1 Jul 2008 06:21:51 GMT (63kb)

Title: Analytic treatment of CRIB Quantum Memories for Light using Two-level

Atoms

Authors: J. J. Longdell and G. H\'etet and M. J. Sellars and P. K. Lam

Categories: quant-ph

Comments: 10 pages

\\

It has recently been discovered that the optical analogue of a gradient echo

in an optically thick material could form the basis of a optical memory that is

both completely efficient and noise free. Here we present analytical

calculation showing this is the case. There is close analogy between the

operation of the memory and an optical system with two beam splitters. We can

use this analogy to calculate efficiencies as a function of optical depth for a

number of quantum memory schemes based on controlled inhomogeneous broadening.

In particular we show that multiple switching leads to a net 100% retrieval

efficiency for the optical gradient echo even in the optically thin case.

\\ ( http://arxiv.org/abs/0807.0067 , 63kb)

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arXiv:0807.0109

Date: Tue, 1 Jul 2008 10:42:01 GMT (57kb,D)

Title: Single particle nonlocality with completely independent reference states

Authors: J. J. Cooper and J. A. Dunningham

Categories: quant-ph

Comments: 10 pages, 5 figures

\\

We describe a scheme to demonstrate the nonlocal properties of a single

particle by showing a violation of Bell's inequality. The scheme is

experimentally achievable as the only inputs are number states and mixed

states, which serve as references to `keep track of the experiment'. These

reference states are created completely independently of one another and

correlated only after all the measurement results have been recorded. This

means that any observed nonlocality must solely be due to the single particle

state. All the techniques used are equally applicable to massive particles as

to photons and as such this scheme could be used to show the nonlocality of

atoms.

\\ ( http://arxiv.org/abs/0807.0109 , 57kb)

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arXiv:0807.0114

Date: Tue, 1 Jul 2008 10:54:12 GMT (186kb)

Title: Noisy quadrature of squeezed light and laser cooling

Authors: G.M. Saxena and A. Agarwal

Categories: quant-ph

Journal-ref: Optics communications,267,124-127,2006

\\

The laser cooling of atoms is a result of the combined effect of doppler

shift, light shift and polarization gradient. These are basically undesirable

phenomena. However, they combine gainfully in realizing laser cooling and

trapping of the atoms. In this paper we discuss the laser cooling of atoms in

the presence of the squeezed light with the decay of atomic dipole moment into

noisy quadrature. We show that the higher decay rate of the atomic dipole

moment into the noisy quadrature, which is also an undesirable effect, may

contribute in realizing larger cooling force vis-a-vis normal laser light.

\\ ( http://arxiv.org/abs/0807.0114 , 186kb)

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arXiv:0807.0233

Date: Tue, 1 Jul 2008 20:07:04 GMT (2210kb)

Title: Hidden vortex lattices in a thermally paired superfluid

Authors: E. K. Dahl, E. Babaev, and A. Sudbo

Categories: cond-mat.stat-mech

Comments: 4 pages, 5 figures. Submitted to Physical Review. Online

supplementary material available, see Ref. 6

\\

We study the evolution of rotational response of a hydrodynamic model of a

two-component superfluid with a non-dissipative drag interaction, as the system

undergoes a transition into a paired phase at finite temperature. The

transition manifests itself in a change of (i) vortex lattice symmetry, and

(ii) nature of vortex state. Instead of a vortex lattice, the system forms a

highly disordered tangle which constantly undergoes merger and reconnecting

processes involving different types of vortices, with a "hidden" breakdown of

translational symmetry.

\\ ( http://arxiv.org/abs/0807.0233 , 2210kb)

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arXiv:0807.0251

Date: Tue, 1 Jul 2008 22:42:09 GMT (1000kb,D)

Title: Symmetry-conserving vortex clusters in small rotating clouds of

ultracold bosons

Authors: Igor Romanovsky, Constantine Yannouleas, Uzi Landman

Categories: cond-mat.mes-hall cond-mat.other

Comments: Revtex 4 with 4 color figures. To appear in Physical Review A (Rapid

Communication). For related papers, see http://www.prism.gatech.edu/~ph274cy/

\\

The properties of a special class of correlated many-body wave functions,

named rotating vortex clusters (RVCs), that preserve the total angular momentum

of a small cloud of trapped rotating bosons are investigated. They have lower

energy and provide a superior description for the formation of vortices

compared to the mean-field Gross-Pitaevskii (GP) states that break the

rotational symmetry. The GP vortex states are shown to be wave packets composed

of such RVC states. Our results suggest that, for a small number of bosons, the

physics is different from that of ideal Bose-Einstein condensates which

characterize larger assemblies

\\ ( http://arxiv.org/abs/0807.0251 , 1000kb)

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arXiv:0807.0412

Date: Wed, 2 Jul 2008 17:57:18 GMT (241kb)

Title: Spin 3/2 fermions with attractive interactions in a one-dimensional

optical lattice: phase diagrams, entanglement entropy, and effect of the trap

Authors: G. Roux, S. Capponi, P. Lecheminant, P. Azaria

Categories: cond-mat.str-el

Comments: 15 pages, 21 figures

\\

We study spin 3/2 fermionic cold atoms with attractive interactions loaded

into a one-dimensional optical lattice. Using numerical techniques, we

determine the phase diagram for a generic density. For the chosen parameters,

one-particle excitations are gapped and the phase diagram is separated into two

regions: one where the two-particle excitation gap is zero, and one where it is

finite. In the first region, the two-body pairing fluctuations (BCS) compete

with the density ones. In the other one, a molecular superfluid (MS) phase, in

which bound-states of four particles form, competes with the density

fluctuations. The properties of the transition line between these two regions

is studied through the behavior of the entanglement entropy. The physical

features of the various phases, comprising leading correlations, Friedel

oscillations, and excitation spectra, are presented. To make the connection

with experiments, the effect of a harmonic trap confinement is taken into

account. In particular, we emphasize the conditions under which the appealing

MS phase can be realized, and how the phases could be probed by using the

density profiles and the associated structure factor. Lastly, the consequences

on the flux quantization of the different nature of the pairing in the BCS and

MS phases are studied in a situation where the condensate is in a ring

geometry.

\\ ( http://arxiv.org/abs/0807.0412 , 241kb)

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arXiv:0807.0413

Date: Wed, 2 Jul 2008 18:13:29 GMT (2304kb)

Title: Vortices in Superfluid Films on Curved Surfaces

Authors: Ari M. Turner, Vincenzo Vitelli and David R. Nelson

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

Comments: 50 pages, 38 figures

\\

We present a systematic study of how vortices in superfluid films interact

with the spatially varying Gaussian curvature of the underlying substrate. The

Gaussian curvature acts as a source for a geometric potential that attracts

(repels) vortices towards regions of negative (positive) Gaussian curvature

independently of the sign of their topological charge. Various experimental

tests involving rotating superfluid films and vortex pinning are first

discussed for films coating gently curved substrates that can be treated in

perturbation theory from flatness. An estimate of the experimental regimes of

interest is obtained by comparing the strength of the geometrical forces to the

vortex pinning induced by the varying thickness of the film which is in turn

caused by capillary effects and gravity. We then present a non-perturbative

technique based on conformal mappings that leads an exact solution for the

geometric potential as well as the geometric correction to the interaction

between vortices. The conformal mapping approach is illustrated by means of

explicit calculations of the geometric effects encountered in the study of some

strongly curved surfaces and by deriving universal bounds on their strength.

\\ ( http://arxiv.org/abs/0807.0413 , 2304kb)

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arXiv:0807.0417

Date: Wed, 2 Jul 2008 18:26:51 GMT (526kb)

Title: Feshbach resonances in ultracold 85Rb-87Rb and 6Li-87Rb mixtures

Authors: Z. Li, S. Singh, T.V. Tscherbul, K.W. Madison

Categories: cond-mat.other

Comments: 8 pages, 5 figures

\\

We present an analysis of experimentally accessible magnetic Feshbach

resonances in ultra-cold hetero-nuclear 85Rb-87Rb and 6Li-87Rb mixtures. Using

recent experimental measurements of the triplet scattering lengths for 6Li-87Rb

and 7Li-87Rb mixtures and Feshbach resonances for one combination of atomic

states, we create model potential curves and fine tune them to reproduce the

measured resonances and to predict the location of several experimentally

relevant resonances in Li-Rb collisions. To model 85Rb-87Rb collisions, we use

accurate Rb_2 potentials obtained previously from the analysis of experiments

on 87Rb-87Rb collisions. We find resonances that occur at very low magnetic

fields, below 10 G, which may be useful for entanglement generation in optical

lattices or atom chip magnetic traps.

\\ ( http://arxiv.org/abs/0807.0417 , 526kb)

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arXiv:0807.0254

Date: Tue, 1 Jul 2008 22:54:02 GMT (874kb,D)

Title: Echo Spectroscopy of Atomic Dynamics in a Gaussian Trap via Phase

Imprints

Authors: Daniel Oblak, Juergen Appel, Patrick Windpassinger, Ulrich Busk Hoff,

Niels Kjaergaard, and Eugene S. Polzik

Categories: quant-ph

\\

We report on the collapse and revival of Ramsey fringe visibility when a

spatially dependent phase is imprinted in the coherences of a trapped ensemble

of two-level atoms. The phase is imprinted via the light shift from a Gaussian

laser beam which couples the dynamics of internal and external degrees of

freedom for the atoms in an echo spectroscopy sequence. The observed revivals

are directly linked to the oscillatory motion of atoms in the trap. An

understanding of the effect is important for quantum state engineering of

trapped atoms.

\\ ( http://arxiv.org/abs/0807.0254 , 874kb)

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arXiv:0807.0506

Date: Thu, 3 Jul 2008 08:22:46 GMT (377kb)

Title: Controlling the Population Imbalance of a Bose-Einstein Condensate by a

Symmetry-Breaking Driving Field

Authors: Luis Morales-Molina, Jiangbin Gong

Categories: cond-mat.other

\\

Nonlinear Floquet states associated with a symmetry-breaking driving field

are exploited to control the dynamics of a Bose-Einstein condensate in a

double-well potential. The population imbalance between the two wells is shown

to be controllable by slowly tuning system parameters along a closed path. The

results extend symmetry-breaking-based quantum control to many-body systems and

extend navigation of linear Floquet states to navigation of nonlinear Floquet

states.

\\ ( http://arxiv.org/abs/0807.0506 , 377kb)

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arXiv:0807.0572

Date: Thu, 3 Jul 2008 14:16:30 GMT (309kb)

Title: Probing the thermal atoms of a Bose gas through Raman transition

Authors: Patrick Navez

Categories: cond-mat.other

Comments: 10 pages, 6 figures submitted to epjb

\\

We explore the many body physics of a Bose condensed atom gas at finite

temperature through the Raman transition between two hyperfine levels. Unlike

the Bragg scattering where the phonon-like nature of the collective excitations

has been observed, a different branch of thermal atom excitation is found

theoretically in the Raman scattering. This excitation is predicted in the

generalized random phase approximation (GRPA) and has a gapped and parabolic

dispersion relation. The gap energy results from the exchange interaction and

is released during the Raman transition. The scattering rate determined versus

the transition frequency $\omega$ and the transferred momentum $\vc{q}$ show

the corresponding resonance around this gap. Nevertheless, the Raman scattering

process is attenuated by the superfluid part of the gas. The macroscopic wave

function of the condensate deforms its shape in order to screen locally the

external potential displayed by the Raman light beams. This screening is total

for a condensed atom transition in order to prevent the condensate from

incoherent scattering. The experimental observation of this result would

explain some of the reasons for which a superfluid condensate moves coherently

without any friction with its surrounding.

\\ ( http://arxiv.org/abs/0807.0572 , 309kb)

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arXiv:0807.0493 (*cross-listing*)

Date: Thu, 3 Jul 2008 07:11:36 GMT (1100kb)

Title: Resonant sequential scattering in two-frequency-pumping superradiance

from a Bose-Einstein condensate

Authors: Fan Yang, Xiaoji Zhou, Juntao Li, Yuankai Chen, Lin Xia, and Xuzong

Chen

Categories: quant-ph cond-mat.other

Comments: Submitted to PRA

\\

We study sequential scattering in superradiance from a Bose-Einstein

condensate pumped by a two-frequency laser beam. We find that the distribution

of atomic side modes presents highly different patterns for various frequency

difference between the two pump components. A novel distribution is observed,

with a frequency difference of eight times the recoil frequency. These

observations reveal that the frequency overlap between the end-fire modes

related to different side modes plays an essential role in the dynamics of

sequential superradiant scattering. The numerical results from a semiclassical

model qualitatively agree with our observations.

\\ ( http://arxiv.org/abs/0807.0493 , 1100kb)

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arXiv:0807.0446

Date: Wed, 2 Jul 2008 20:17:49 GMT (2235kb)

Title: Strongly-interacting bosons in a disordered optical lattice

Authors: M. White, M. Pasienski, D. McKay, S. Zhou, D. Ceperley, B. DeMarco

Categories: physics.atom-ph

Comments: 15 pages, 4 figures

\\

Disorder, prevalent in nature, is intimately involved in such spectacular

effects as the fractional quantum Hall effect and vortex pinning in type-II

superconductors. Understanding the role of disorder is therefore of fundamental

interest to materials research and condensed matter physics. Universal

behavior, such as Anderson localization, in disordered non-interacting systems

is well understood. But, the effects of disorder combined with strong

interactions remains an outstanding challenge to theory. Here, we

experimentally probe a paradigm for disordered, strongly-correlated bosonic

systems-the disordered Bose-Hubbard (DBH) model-using a Bose-Einstein

condensate (BEC) of ultra-cold atoms trapped in a completely characterized

disordered optical lattice. We determine that disorder suppresses condensate

fraction for superfluid (SF) or coexisting SF and Mott insulator (MI) phases by

independently varying the disorder strength and the ratio of tunneling to

interaction energy. In the future, these results can constrain theories of the

DBH model and be extended to study disorder for strongly-correlated fermionic

particles.

\\ ( http://arxiv.org/abs/0807.0446 , 2235kb)

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The replacements:

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arXiv:0801.0383

replaced with revised version Fri, 27 Jun 2008 14:01:28 GMT (412kb)

Title: Vortex-lattice formation and melting in a nonrotating Bose-Einstein

condensate

Authors: Gary Ruben, David M. Paganin, and Michael J. Morgan (School of

Physics, Monash University)

Categories: cond-mat.other nlin.PS

Comments: 10 pages, 8 figures, REVTeX4, Added a section following the

introduction and clarified the description of the numerical model. Added

references

\\ ( http://arxiv.org/abs/0801.0383 , 412kb)

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arXiv:0801.2343

replaced with revised version Fri, 27 Jun 2008 17:47:05 GMT (337kb)

Title: Ultracold bosons in lattices with binary disorder

Authors: K.V.Krutitsky, M.Thorwart, R.Egger, R.Graham

Categories: cond-mat.dis-nn cond-mat.other

Journal-ref: Phys.Rev.A 77, 053609 (2008)

DOI: 10.1103/PhysRevA.77.053609

\\ ( http://arxiv.org/abs/0801.2343 , 337kb)

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arXiv:0806.4258

replaced with revised version Fri, 27 Jun 2008 00:07:33 GMT (1234kb)

Title: Photon echoes generated by reversing magnetic field gradients in a

rubidium vapour

Authors: G. H\'etet, M. Hosseini, B. Sparkes, D. Oblak, P. K. Lam and B. C.

Buchler

Categories: quant-ph

\\ ( http://arxiv.org/abs/0806.4258 , 1234kb)

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arXiv:0806.4378

replaced with revised version Mon, 30 Jun 2008 16:39:26 GMT (11kb)

Title: Vortex pseudomomentum and dissipation in a superfluid vortex lattice

Authors: H. M. Cataldo

Categories: cond-mat.stat-mech cond-mat.other physics.flu-dyn

Comments: 11 pages, no figures. Typo corrected in equation (28)

Journal-ref: J. Phys. A: Math. Theor. 41 (2008) 295501 (9pp)

DOI: 10.1088/1751-8113/41/29/295501

\\ ( http://arxiv.org/abs/0806.4378 , 11kb)

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arXiv:0712.0205

replaced with revised version Tue, 1 Jul 2008 12:46:11 GMT (52kb)

Title: Virial equation of state for unitary fermion thermodynamics with

non-Gaussian correlations

Authors: Ji-sheng Chen, Jia-rong Li, Yan-ping Wang, Xiang-jun Xia

Categories: cond-mat.stat-mech hep-ph nucl-th quant-ph

Comments: Typos corrected; references updated; one figure added

\\ ( http://arxiv.org/abs/0712.0205 , 52kb)

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arXiv:0802.3945

replaced with revised version Tue, 1 Jul 2008 18:45:11 GMT (232kb)

Title: Population imbalanced fermions in harmonically trapped optical lattices

Authors: M. Iskin and C. J. Williams

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

Comments: 4 pages with 4 figures, accepted to appear in PRA

\\ ( http://arxiv.org/abs/0802.3945 , 232kb)

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arXiv:cond-mat/0703612

replaced with revised version Thu, 3 Jul 2008 13:11:39 GMT (25kb)

Title: Manifestation of a gap due to the exchange energy in a spinor condensate

Authors: Patrick Navez

Categories: cond-mat.stat-mech

Comments: 5 pages, 2 figures

Journal-ref: Phyisca A 387, 4070 (2008)

\\ ( http://arxiv.org/abs/cond-mat/0703612 , 25kb)

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arXiv:0803.0846

replaced with revised version Thu, 3 Jul 2008 09:30:37 GMT (523kb)

Title: Ground State Properties of a Tonks-Girardeau Gas in a Split Trap

Authors: J. Goold and Th. Busch

Categories: cond-mat.other quant-ph

Comments: 7 pages, 10 figures.New Fig. 8 added and text reference to figure in

Sec IV C. New reference [15] added

Journal-ref: Phys. Rev. A 77, 063601 (2008)

\\ ( http://arxiv.org/abs/0803.0846 , 523kb)

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arXiv:0806.0598

replaced with revised version Thu, 3 Jul 2008 17:57:32 GMT (117kb)

Title: Fermion-mediated interactions in a dilute Bose-Einstein condensate

Authors: D. H. Santamore, Eddy Timmermans

Categories: cond-mat.stat-mech physics.atom-ph

Comments: 16 pages, 6 figures, typo corrected

\\ ( http://arxiv.org/abs/0806.0598 , 117kb)

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arXiv:0806.2427

replaced with revised version Thu, 3 Jul 2008 14:27:21 GMT (487kb)

Title: Magnetic interactions of cold atoms with anisotropic conductors

Authors: T. David (1), Y. Japha (1), V. Dikovsky (1), R. Salem (1), C. Henkel

(2), R. Folman (1) ((1) Ben-Gurion University of the Negev, Be'er Sheva,

Israel. (2) Institut f\"ur Physik und Astronomie, Universit\"at Potsdam,

Germany.)

Categories: cond-mat.other cond-mat.mtrl-sci quant-ph

Comments: Selected as a Highlight paper in the European Physical Journal D

Journal-ref: Euro. Phys. J. D. 48, 321-332 (2008)

DOI: 10.1140/epjd/e2008-00119-x

\\ ( http://arxiv.org/abs/0806.2427 , 487kb)

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arXiv:0807.0233

replaced with revised version Thu, 3 Jul 2008 12:42:29 GMT (2377kb)

Title: Hidden vortex lattices in a thermally paired superfluid

Authors: E. K. Dahl, E. Babaev, and A. Sudbo

Categories: cond-mat.stat-mech

Comments: 4 pages, 5 figs. Submitted to Physical Review. Online suppl. material

available; Ref. 6. V2: Fig. 1 re-sent, URL in Ref. 6 corrected

\\ ( http://arxiv.org/abs/0807.0233 , 2377kb)

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Till next time,

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 Jul 15 2008 - 17:16:38 EST

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