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

Date: Fri, 26 Sep 2008 08:36:09 +1000

Date: Fri, 26 Sep 2008 08:36:09 +1000

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

Hello again,

There were 26 new preprints and 10 replacements this week:

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arXiv:0809.0993

Date: Fri, 5 Sep 2008 09:53:44 GMT (800kb,D)

Title: Vortex waves in trapped Bose-Einstein condensates

Authors: T. P. Simula, T. Mizushima, and K. Machida

Categories: cond-mat.other

Comments: 7 pages, 7 figures

\\

We have theoretically studied vortex waves of Bose-Einstein condensates in

elongated harmonic traps. Our focus is on the axisymmetric varicose waves and

helical Kelvin waves of singly quantized vortex lines. Growth and decay

dynamics of both types of vortex waves are discussed. We propose a

straightforward method to experimentally create these vortex waves on demand.

\\ ( http://arxiv.org/abs/0809.0993 , 800kb)

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arXiv:0809.1002

Date: Fri, 5 Sep 2008 13:14:01 GMT (297kb)

Title: Stochastic field equation for the canonical ensemble of a Bose gas

Authors: Sigmund Heller, Walter T. Strunz

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

\\

We present a novel norm preserving stochastic evolution equation for a Bose

field. Ensemble averages are quantum expectation values in the canonical

ensemble. This numerically very stable equation suppresses high-energy

fluctuations exponentially, preventing cutoff problems to occur. We present 3D

simulations for an ideal gas in various trapping potentials focussing on ground

state occupation numbers and spatial correlation functions for a wide range of

temperatures above and below the critical temperature. Although rigorously

valid for non-interacting Bosons only, we argue that weakly interacting Bose

gases may also be amenable to this approach, in the usual mean-field

approximation.

\\ ( http://arxiv.org/abs/0809.1002 , 297kb)

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arXiv:0809.1032

Date: Fri, 5 Sep 2008 14:02:30 GMT (1355kb)

Title: Avoided level crossing spectroscopy with dressed matter waves

Authors: Andre Eckardt and Martin Holthaus

Categories: cond-mat.other

Comments: 4 pages, 3 figures

\\

We devise a method for probing resonances of macroscopic matter waves in

shaken optical lattices by monitoring their response to slow parameter changes,

and show that such resonances can be disabled by particular choices of the

driving amplitude. The theoretical analysis of this scheme reveals far-reaching

analogies between dressed atoms and time-periodically forced matter waves.

\\ ( http://arxiv.org/abs/0809.1032 , 1355kb)

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arXiv:0809.1090

Date: Fri, 5 Sep 2008 19:47:29 GMT (9kb)

Title: Temperature measurements of a Bose--Einstein condensate by

ultra--intense light pulses

Authors: Abel Camacho, Luis F. Barragan, and Alfredo Macias

Categories: cond-mat.stat-mech

Comments: Four pages

\\

Experimentally the temperature in a Bose--Einstein condensate is always

deduced resorting to the comparison between the Maxwell--Boltzmann velocity

distribution function and the density profile in momentum space. Though a

successful method it is an approximation, since it also implies the use of

classical statistical mechanics at temperatures close to the condensation

temperature where quantal effects play a relevant role. The present work puts

forward a new method in which we use an ultra--intense light pulse and a

nonlinear optical material as detectors for differences in times--of--flight.

This experimental value shall be compared against the result here calculated,

using the Bose--Einstein distribution function, which is a

temperature--dependent variable, and in this way the temperature of the

condensate is obtained.

\\ ( http://arxiv.org/abs/0809.1090 , 9kb)

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arXiv:0809.0936

Date: Fri, 5 Sep 2008 00:40:04 GMT (75kb)

Title: Inelastic and elastic collision rates for triplet states of ultracold

strontium

Authors: A. Traverso, R. Chakraborty, Y. N. Martinez de Escobar, P. G.

Mickelson, S. B. Nagel, M. Yan, and T. C. Killian

Categories: physics.atom-ph

Comments: 4 pages 5 figures

\\

We report measurement of the inelastic and elastic collision rates for

^{88}Sr atoms in the (5s5p)^3P_0 state in a crossed-beam optical dipole trap.

This is the first measurement of ultracold collision properties of a ^3P_0

level in an alkaline-earth atom or atom with similar electronic structure.

Since the (5s5p)^3P_0 state is the lowest level of the triplet manifold, large

loss rates indicate the importance of principle-quantum-number-changing

collisions at short range. We also provide an estimate of the collisional loss

rates for the (5s5p){^3P_2} state.

\\ ( http://arxiv.org/abs/0809.0936 , 75kb)

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arXiv:0809.1054

Date: Fri, 5 Sep 2008 16:13:32 GMT (347kb,D)

Title: Matter-wave cavity gravimeter

Authors: F. Impens, P. Bouyer and Ch. J. Bord\'e

Categories: physics.atom-ph physics.optics

Comments: 15 pages, 6 Figures. The expression for the atomic mirror focal

length has been corrected. Other minor corrections and actualizations to the

previously published version

Journal-ref: Appl. Phys. B: Laser and Optics 84, 603-615 (2006)

\\

We propose a gravimeter based on a matter-wave resonant cavity loaded with a

Bose-Einstein condensate and closed with a sequence of periodic Raman pulses.

The gravimeter sensitivity increases quickly with the number of cycles

experienced by the condensate inside the cavity. The matter wave is refocused

thanks to a spherical wave-front of the Raman pulses. This provides a

transverse confinement of the condensate which is discussed in terms of a

stability analysis. We develop the analogy of this device with a resonator in

momentum space for matter waves.

\\ ( http://arxiv.org/abs/0809.1054 , 347kb)

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arXiv:0809.1259

Date: Sun, 7 Sep 2008 23:09:06 GMT (793kb)

Title: Robustness of Heisenberg-limited interferometry with balanced Fock

states

Authors: D. Meiser and M. J. Holland

Categories: quant-ph

Comments: 13 pages, 6 figures; high-resolution version can be obtained from

authors

\\

Interferometry with Heisenberg limited phase resolution may play an important

role in the next generation of atomic clocks, gravitational wave detectors, and

in quantum information science. For experimental implementations the robustness

of the phase resolution is crucial since any experimental realization will be

subject to imperfections. In this article we study the robustness of phase

reconstruction with two number states as input subject to fluctuations in the

state preparation. We find that the phase resolution is insensitive to

fluctuations in the total number of particles and robust against noise in the

number difference at the input. The phase resolution depends on the uncertainty

in the number difference in a universal way that has a clear physical

interpretation: Fundamental noise due to the Heisenberg limit and noise due to

state preparation imperfection contribute essentially independently to the

total uncertainty in the phase. For number difference uncertainties less than

one the first noise source is dominant and the phase resolution is essentially

Heisenberg limited. For number difference uncertainties greater than one the

noise due to state preparation imperfection is dominant and the phase

resolution deteriorates linearly with the number difference uncertainty.

\\ ( http://arxiv.org/abs/0809.1259 , 793kb)

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arXiv:0809.1276

Date: Mon, 8 Sep 2008 05:30:05 GMT (89kb)

Title: Matter Wave Radiation

Authors: Yongyi Huang

Categories: physics.gen-ph

Comments: 4 pages, 1 figures, submitted to PRL

\\

The concept of Matter Wave Radiation (MWR) is put forward, and the equation

of MWR is established. The equation is applied to a free particle without any

potential. A new effect of MWR is discussed.

\\ ( http://arxiv.org/abs/0809.1276 , 89kb)

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arXiv:0809.1422

Date: Mon, 8 Sep 2008 20:05:57 GMT (933kb)

Title: Quantum phases of a two-dimensional dipolar Fermi gas

Authors: G. M. Bruun and E. Taylor

Categories: cond-mat.other

Comments: 4 pages, 4 figures

\\

We examine the superfluid and collapse instabilities of a quasi

two-dimensional gas of dipolar fermions aligned by an orientable external

field. It is shown that the interplay between the anisotropy of the dipolar

interaction, the geometry of the system, and the p-wave symmetry of the

superfluid order parameter means that the effective interaction for pairing can

be made very large without the system collapsing. This leads to a broad region

in the phase diagram where the system forms a stable superfluid. Analyzing the

superfluid transition at finite temperatures, we calculate the

Berezinskii--Kosterlitz--Thouless temperature as a function of the dipole

angle.

\\ ( http://arxiv.org/abs/0809.1422 , 933kb)

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arXiv:0809.1448

Date: Mon, 8 Sep 2008 20:50:17 GMT (301kb)

Title: Beyond mean field effects in the high momentum energy spectrum of a Bose

gas: revisiting Beliaev's theory

Authors: Shai Ronen

Categories: cond-mat.other

\\

The well-known Bogoliubov expression for the spectrum of a weakly interacting

dilute Bose gas becomes inadequate when the density or interactions strength

are increased. The corrections to the spectrum due to stronger interactions

were first considered by Beliaev (S. T. Beliaev, Sov. Phys.-JETP, 7:289,

(1958)). We revisit Beliaev's theory and consider its application to a dilute

gas with van der Waals interactions, where the scattering length may be tuned

via a Fano-Feshbach resonance. We numerically evaluate Beliaev's expression for

the excitation spectrum in the intermediate momentum regime, and we also

examine the consequences of the momentum dependence of the two-body scattering

amplitude.These results are relevant to the interpretation of a recent Bragg

spectroscopy experiment of a strongly interacting Bose gas.

\\ ( http://arxiv.org/abs/0809.1448 , 301kb)

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arXiv:0809.1464

Date: Tue, 9 Sep 2008 00:15:31 GMT (1131kb)

Title: Metallic and Insulating Phases of Repulsively Interacting Fermions in a

3D Optical Lattice

Authors: U. Schneider, L. Hackermuller, S. Will, Th. Best, I. Bloch, T. A.

Costi, R. W. Helmes, D. Rasch, and A. Rosch

Categories: cond-mat.str-el

Comments: 21 pages, 5 figures and additional supporting material

\\

The fermionic Hubbard model plays a fundamental role in the description of

strongly correlated materials. Here we report on the realization of this

Hamiltonian using a repulsively interacting spin mixture of ultracold $^{40}$K

atoms in a 3D optical lattice. We have implemented a new method to directly

measure the compressibility of the quantum gas in the trap using in-situ

imaging and independent control of external confinement and lattice depth.

Together with a comparison to ab-initio Dynamical Mean Field Theory

calculations, we show how the system evolves for increasing confinement from a

compressible dilute metal over a strongly-interacting Fermi liquid into a band

insulating state. For strong interactions, we find evidence for an emergent

incompressible Mott insulating phase.

\\ ( http://arxiv.org/abs/0809.1464 , 1131kb)

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arXiv:0809.1468

Date: Tue, 9 Sep 2008 01:04:15 GMT (569kb)

Title: Bose-Einstein condensation in an optical lattice: A perturbation

approach

Authors: C. Trallero-Giner, V. Lopez-Richard, Ming-Chiang Chung, Andreas

Buchleitner

Categories: cond-mat.other

Comments: 9 pages, 6 figures

\\

We derive closed analytical expressions for the order parameter $\Phi (x)$

and for the chemical potential $\mu $ of a Bose-Einstein Condensate loaded into

a harmonically confined, one dimensional optical lattice, for sufficiently

weak, repulsive or attractive interaction, and not too strong laser

intensities. Our results are compared with exact numerical calculations in

order to map out the range of validity of the perturbative analytical approach.

We identify parameter values where the optical lattice compensates the

interaction-induced nonlinearity, such that the condensate ground state

coincides with a simple, single particle harmonic oscillator wavefunction.

\\ ( http://arxiv.org/abs/0809.1468 , 569kb)

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arXiv:0809.1486

Date: Tue, 9 Sep 2008 06:35:40 GMT (817kb,D)

Title: The Bose-Hubbard ground state: extended Bogoliubov and variational

methods compared with time-evolving block decimation

Authors: Ippei Danshita and Pascal Naidon

Categories: cond-mat.other

Comments: 9 pages, 8 figures

\\

We determine the ground-state properties of a gas of interacting bosonic

atoms in a one-dimensional optical lattice. The system is modelled by the

Bose-Hubbard Hamiltonian. We show how to apply the time-evolving block

decimation method to systems with periodic boundary conditions, and employ it

as a reference to find the ground state of the Bose-Hubbard model. Results are

compared with recently proposed approximate methods, such as

Hartree-Fock-Bogoliubov (HFB) theories generalised for strong interactions and

the variational Bijl-Dingle-Jastrow method. We find that all HFB methods do not

bring any improvement to the Bogoliubov theory and therefore provide correct

results only in the weakly-interacting limit, where the system is deeply in the

superfluid regime. On the other hand, the variational Bijl-Dingle-Jastrow

method is applicable for much stronger interactions, but is essentially limited

to the superfluid regime as it reproduces the superfluid-Mott insulator

transition only qualitatively.

\\ ( http://arxiv.org/abs/0809.1486 , 817kb)

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arXiv:0809.1487

Date: Tue, 9 Sep 2008 05:31:56 GMT (2689kb,D)

Title: Dynamics and statistical mechanics of ultra-cold Bose gases using

c-field techniques

Authors: P. B. Blakie, A. S. Bradley, M. J. Davis, R. J. Ballagh, and C. W.

Gardiner

Categories: cond-mat.stat-mech

Comments: 94 pages, 30 figures

\\

We review phase space techniques based on the Wigner representation that

provide an approximate description of dilute ultra-cold Bose gases. In this

approach the quantum field evolution can be represented using equations of

motion of a similar form to the Gross-Pitaevskii equation but with stochastic

modifications that include quantum effects in a controlled degree of

approximation. These techniques provide a practical quantitative description of

both equilibrium and dynamical properties of Bose gas systems. We develop

versions of the formalism appropriate at zero temperature, where quantum

fluctuations can be important, and at finite temperature where thermal

fluctuations dominate. The numerical techniques necessary for implementing the

formalism are discussed in detail, together with methods for extracting

observables of interest. Numerous applications to a wide range of phenomena are

presented.

\\ ( http://arxiv.org/abs/0809.1487 , 2689kb)

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arXiv:0809.1539

Date: Tue, 9 Sep 2008 12:38:43 GMT (222kb)

Title: Pair correlations of a spin-imbalanced Fermi gas on two-leg ladders

Authors: A. E. Feiguin and F. Heidrich-Meisner

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

Comments: 4 pages Revtex4, 4 eps figures

\\

We present a numerical study of the pair correlations of a spin-imbalanced

two-leg ladder with attractive interactions. The density matrix renormalization

group method is used to obtain the phase diagram of the system as a function of

chemical potential and magnetic field, and we identify regions that can

potentially harbor Fulde-Ferrel-Larkin-Ovchinnikov (FFLO)-like physics. The

presence of FFLO-like correlations is then substantiated by results for the

pair structure factor, which, depending on filling and the ratio of hopping

matrix elements along the legs and rungs, can exhibit multiple pairing

wave-vectors. We show that these paring correlations also exist in the presence

of a harmonic trapping potential, as typically present in experiments.

Furthermore, we discuss phase separation scenarios induced by the trap, which

differ from the case of isolated chains.

\\ ( http://arxiv.org/abs/0809.1539 , 222kb)

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arXiv:0809.1675

Date: Tue, 9 Sep 2008 21:26:34 GMT (263kb)

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

\\

The energy spectrum for three species of identical fermionic atoms close to a

Feshbach resonance is computed by use of a non-perturbative flow equation.

Already a simple truncation shows that for large scattering length $|a|$ the

lowest energy state is a "trion" bound state of three atoms. At the location of

the resonance, for $|a|\to\infty$, we find an infinite set of trion bound

states, with exponentially decreasing binding energy. This feature is similar

to the Efimov states for bosonic atoms. It arises from limit cycle scaling,

which also leads to a periodic dependence of the three body scattering coupling

on $\ln |a|$. Extending our findings by continuity to non-zero density and

temperature we find that a "trion phase" separates a BEC and a BCS phase, with

interesting quantum phase transitions for T=0.

\\ ( http://arxiv.org/abs/0809.1675 , 263kb)

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arXiv:0809.1776

Date: Wed, 10 Sep 2008 12:16:56 GMT (127kb)

Title: Dissipation induced coherence of a two-mode Bose-Einstein condensate

Authors: D. Witthaut, F. Trimborn, and S. Wimberger

Categories: cond-mat.other

Comments: 10 pages, 5 figures

\\

We discuss the dynamics of a Bose-Einstein condensate in a double-well trap

subject to phase noise and particle loss. The phase coherence of a

weakly-interacting condensate as well as the response to an external driving

show a pronounced stochastic resonance effect: Both quantities become maximal

for a finite value of the dissipation rate matching the intrinsic time scales

of the system. Even stronger effects are observed when dissipation acts in

concurrence with strong inter-particle interactions, restoring the purity of

the condensate almost completely and increasing the phase coherence

significantly.

\\ ( http://arxiv.org/abs/0809.1776 , 127kb)

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arXiv:0809.1814

Date: Wed, 10 Sep 2008 15:16:25 GMT (244kb)

Title: Collective oscillations of a Fermi gas in the unitarity limit:

Temperature effects and the role of pair correlations

Authors: S. Riedl, E. R. Sanchez Guajardo, C. Kohstall, A. Altmeyer, M. J.

Wright, J. Hecker Denschlag, R. Grimm, G. M. Bruun, H. Smith

Categories: cond-mat.other

\\

We present detailed measurements of the frequency and damping of three

different collective modes in an ultracold trapped Fermi gas of $^6$Li atoms

with resonantly tuned interactions. The measurements are carried out over a

wide range of temperatures. We focus on the unitarity limit, where the

scattering length is much greater than all other relevant length scales. The

results are compared to theoretical calculations that take into account Pauli

blocking and pair correlations in the normal state above the critical

temperature for superfluidity. We show that these two effects nearly compensate

each other and the behavior of the gas is close to the one of a classical gas.

\\ ( http://arxiv.org/abs/0809.1814 , 244kb)

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arXiv:0809.1818

Date: Wed, 10 Sep 2008 15:28:09 GMT (26kb)

Title: Transition to the giant vortex state for a Bose-Einstein condensate in a

rotating anharmonic trap

Authors: Nicolas Rougerie

Categories: cond-mat.other

Comments: 40 pages

MSC-class: 35Q55,47J30,76M23

\\

We study the fast rotation limit for a Bose-Einstein condensate in a

quadratic plus quartic confining potential within the framework of the two

dimensional Gross-Pitaevskii energy functional. As the rotation speed tends to

infinity, the condensate undergoes a phase transition to the so-called giant

vortex state: an annulus with pure irrotational flow encircling a central

low-density hole around which there is a macroscopic phase circulation.

\\ ( http://arxiv.org/abs/0809.1818 , 26kb)

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arXiv:0809.1820

Date: Wed, 10 Sep 2008 15:30:14 GMT (50kb)

Title: Extended Thomas-Fermi Density Functional for the Unitary Fermi Gas

Authors: Luca Salasnich and Flavio Toigo

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

Comments: 7 pages, 3 figures, 1 table

\\

We determine the energy density $\xi (3/5) n \varepsilon_F$ and the gradient

correction $\lambda \hbar^2(\nabla n)^2/(8m n)$ of the extended Thomas-Fermi

(ETF) density functional, where $n$ is number density and $\varepsilon_F$ is

Fermi energy, for a trapped two-components Fermi gas with infinite scattering

length (unitary Fermi gas) on the basis of recent diffusion Monte Carlo (DMC)

calculations [Phys. Rev. Lett. {\bf 99}, 233201 (2007)]. In particular we find

that $\xi=0.455$ and $\lambda=0.13$ give the best fit of the DMC data with an

even number $N$ of particles. We also study the odd-even splitting $\gamma

N^{1/9} \hbar \omega$ of the ground-state energy for the unitary gas in a

harmonic trap of frequency $\omega$ determining the constant $\gamma$. Finally

we investigate the effect of the gradient term in the time-dependent ETF model

by introducing generalized Galilei-invariant hydrodynamics equations.

\\ ( http://arxiv.org/abs/0809.1820 , 50kb)

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arXiv:0809.1892

Date: Wed, 10 Sep 2008 22:17:55 GMT (22kb)

Title: Universal Properties of the Ultra-Cold Fermi Gas

Authors: Shizhong Zhang and Anthony J. Leggett

Categories: cond-mat.str-el

\\

We present some general considerations on the properties of a two-component

ultra-cold Fermi gas along the BEC-BCS crossover. It is shown that the

interaction energy and the ground state energy can be written in terms of a

single dimensionless function $h({\xi,\tau})$, where $\xi=-(k_Fa_s)^{-1}$ and

$\tau=T/T_F$. The function $h(\xi,\tau)$ incorporates all the many-body physics

and naturally occurs in other physical quantities as well. In particular, we

show that the RF-spectroscopy shift $\bar{\d\o}(\xi,\tau)$ and the molecular

fraction $f_c(\xi,\tau)$ in the closed channel can be expressed in terms of

$h(\xi,\tau)$ and thus have identical temperature dependence. The conclusions

should have testable consequences in future experiments.

\\ ( http://arxiv.org/abs/0809.1892 , 22kb)

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arXiv:0809.1947

Date: Thu, 11 Sep 2008 10:17:57 GMT (20kb)

Title: Finite size effects for the gap in the excitation spectrum of the

one-dimensional Hubbard model

Authors: M. Colom\'e-Tatch\'e, S. I. Matveenko, G. V. Shlyapnikov

Categories: cond-mat.str-el

Comments: 17 pages, 3 figures

\\

We study finite size effects for the gap of the quasiparticle excitation

spectrum in the one-dimensional Hubbard model with on-site attraction. Two type

of corrections to the result of the thermodynamic limit are obtained. First of

all, there is a power law correction due to gapless excitations which behaves

as $1/N_a$, where $N_a$ is the number of lattice sites. Second, we obtain an

exponential correction related to the existence of gapped excitations. In the

weakly interacting regime this correction behaves as $\sim \exp (-N_a

\Delta_{\infty}/4 t)$, where $t$ is the hopping amlitude and $\Delta_{\infty}$

is the gap in the thermodynamic limit, and it can dominate over the power law

correction. For sufficiently small number of particles, which can be of the

order of thousands in the weakly interacting regime, both corrections become of

the order of $\Delta_{\infty}$ and the gap is dominated by finite size effects.

\\ ( http://arxiv.org/abs/0809.1947 , 20kb)

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arXiv:0809.2078

Date: Thu, 11 Sep 2008 18:49:38 GMT (594kb)

Title: Commensurability and hysteretic evolution of vortex configurations in

rotating optical lattices

Authors: Daniel S. Goldbaum, Erich J. Mueller

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

Comments: 8 pages, 3 figures. Some, but not all, material is included in

arXiv:0807.3609. A new simulation of a time-of-flight absorption image is

included

\\

We present a theoretical study of vortices within a harmonically trapped

Bose-Einstein condensate in a rotating optical lattice. Due to the competition

between vortex-vortex interactions and pinning to the optical lattice we find a

very complicated energy landscape, which leads to hysteretic evolution. The

qualitative structure of the vortex configurations depends on the

commensurability between the vortex density and the site density -- with

regular lattices when these are commensurate, and concentric rings when they

are not. We model the imaging of these structures by calculating time-of-flight

column densities. As in the absence of the optical lattice, the vortices are

much more easily observed in a time-of-flight image than \emph{in-situ}.

\\ ( http://arxiv.org/abs/0809.2078 , 594kb)

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arXiv:0809.1984

Date: Thu, 11 Sep 2008 12:59:03 GMT (54kb,D)

Title: Excess noise and strong depletion of a Bose-Einstein condensate in an

optical cavity

Authors: G. Szirmai, D. Nagy, P. Domokos

Categories: quant-ph

Comments: 4 pages, 3 figures included in text

\\

Quantum fluctuations of a cavity field coupled into the motion of ultracold

bosons can be strongly amplified by a mechanism analogous to the Petermann

excess noise factor in lasers with unstable cavities. For a Bose-Einstein

condensate in a stable optical resonator, the excess noise effect amounts to a

significant depletion on long timescales.

\\ ( http://arxiv.org/abs/0809.1984 , 54kb)

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arXiv:0809.2007

Date: Thu, 11 Sep 2008 14:30:13 GMT (561kb,D)

Title: Nonlinear Dynamics of Bose-Einstein Condensates with Long-Range

Interactions

Authors: G. Wunner, H. Cartarius, T. Fab\v{c}i\v{c}, P. K\"oberle, J. Main, T.

Schwidder

Categories: quant-ph

Comments: 10 pages, 5 figures, Proceedings of the "7th International Summer

School/Conference LET'S FACE CHAOS THROUGH NONLINEAR DYNAMICS", CAMTP,

University of Maribor, Slovenia, 29 June - 13 July 2008

\\

The motto of this paper is: Let's face Bose-Einstein condensation through

nonlinear dynamics. We do this by choosing variational forms of the condensate

wave functions (of given symmetry classes), which convert the Bose-Einstein

condensates via the time-dependent Gross-Pitaevskii equation into Hamiltonian

systems that can be studied using the methods of nonlinear dynamics. We

consider in particular cold quantum gases where long-range interactions between

the neutral atoms are present, in addition to the conventional short-range

contact interaction, viz. gravity-like interactions, and dipole-dipole

interactions. The results obtained serve as a useful guide in the search for

nonlinear dynamics effects in numerically exact quantum calculations for

Bose-Einstein condensates. A main result is the prediction of the existence of

stable islands as well as chaotic regions for excited states of dipolar

condensates, which could be checked experimentally.

\\ ( http://arxiv.org/abs/0809.2007 , 561kb)

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arXiv:0809.1999

Date: Thu, 11 Sep 2008 13:53:16 GMT (544kb)

Title: Optimal geometry for efficient loading of an optical dipole trap

Authors: Leszek Krzemien, Andrzej Szczepkowicz, Adam Wojciechowski, Krzysztof

Brzozowski, Michael Kruger, Michal Zawada, Marcin Witkowski, Jerzy

Zachorowski, Wojciech Gawlik

Categories: physics.atom-ph

Comments: 6 figures

\\

One important factor which determines efficiency of loading cold atoms into

an optical dipole trap from a magneto-optical trap is the distance between the

trap centers. By studying this efficiency for various optical trap depths

(2--110 mK) we find that for optimum dipole trap loading, longitudinal

displacements up to 15 mm are necessary. An explanation for this observation is

presented and compared with other work and a simple analytical formula is

derived for the optimum distance between the trap centers.

\\ ( http://arxiv.org/abs/0809.1999 , 544kb)

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The replacements:

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arXiv:0801.3127

replaced with revised version Sat, 6 Sep 2008 04:52:45 GMT (38kb)

Title: Phase Diagram of Cold Polarized Fermi Gas in Two Dimensions

Authors: Lianyi He and Pengfei Zhuang

Categories: cond-mat.supr-con cond-mat.other cond-mat.str-el hep-ph nucl-th

physics.atom-ph

Comments: V3: extended version according to referee's comment. 12 pages, 6

figures. Analytical results of density profile in trapped system are

reported; V4: Version accepted by Physical Review A

\\ ( http://arxiv.org/abs/0801.3127 , 38kb)

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arXiv:0712.2571

replaced with revised version Tue, 9 Sep 2008 13:34:31 GMT (860kb,D)

Title: Ultracold atomic gas in non-Abelian "magnetic" fields: the quantum Hall

effect supremacy

Authors: N. Goldman, A. Kubasiak, P. Gaspard and M. Lewenstein

Categories: cond-mat.mes-hall

Comments: 6 pages, 5 figures

\\ ( http://arxiv.org/abs/0712.2571 , 860kb)

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arXiv:0801.3984

replaced with revised version Tue, 9 Sep 2008 08:59:43 GMT (12kb)

Title: Effect of fluctuations on the superfluid-supersolid phase transition on

the lattice

Authors: Ralf Sch\"utzhold, Michael Uhlmann, Uwe R. Fischer

Categories: cond-mat.other

Comments: 5 pages of RevTex4; as published in Physical Review A

Journal-ref: Phys. Rev. A 78, 033604 (2008)

DOI: 10.1103/PhysRevA.78.033604

\\ ( http://arxiv.org/abs/0801.3984 , 12kb)

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arXiv:0807.2979

replaced with revised version Tue, 9 Sep 2008 17:50:36 GMT (59kb)

Title: The two-body problem of ultra-cold atoms in a harmonic trap

Authors: Patrick Shea, Brandon P. van Zyl, Rajat K. Bhaduri

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

\\ ( http://arxiv.org/abs/0807.2979 , 59kb)

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arXiv:0808.0054

replaced with revised version Wed, 10 Sep 2008 18:26:03 GMT (165kb,D)

Title: Trapping of Ultracold Atoms in a Hollow-core Photonic Crystal Fiber

Authors: Caleb A. Christensen, Sebastian Will, Michele Saba, Gyu-Boong Jo,

Yong-Il Shin, Wolfgang Ketterle, David Pritchard

Categories: cond-mat.other

Comments: 4 pages, 3 figures, corrected author list, added refs, changed figs,

changed content, accepted by PRA

\\ ( http://arxiv.org/abs/0808.0054 , 165kb)

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arXiv:0805.2990

replaced with revised version Wed, 10 Sep 2008 14:36:54 GMT (18kb)

Title: Motion of quantum particle in dilute Bose-Einstein condensate at zero

temperature

Authors: Alexey Novikov and Mikhail Ovchinnikov

Categories: quant-ph

\\ ( http://arxiv.org/abs/0805.2990 , 18kb)

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arXiv:0707.3065

replaced with revised version Thu, 11 Sep 2008 10:07:35 GMT (185kb)

Title: Exact vortex nucleation and cooperative vortex tunneling in dilute BECs

Authors: M.I. Parke, N.K. Wilkin, J.M.F. Gunn and A. Bourne

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

Comments: 4 pages,4 figures

Journal-ref: PRL. 101, 110401 (2008)

DOI: 10.1103/PhysRevLett.101.110401

\\ ( http://arxiv.org/abs/0707.3065 , 185kb)

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arXiv:0712.4217

replaced with revised version Thu, 11 Sep 2008 17:16:05 GMT (155kb)

Title: A vortex dipole in a trapped two-dimensional Bose-Einstein condensate

Authors: Weibin Li, Masudul Haque, Stavros Komineas

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

Comments: 7 pages, 8 figures. In v2, some details are moved to Appendix

Journal-ref: Phys. Rev. A 77, 053610 (2008)

\\ ( http://arxiv.org/abs/0712.4217 , 155kb)

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arXiv:0802.3211

replaced with revised version Thu, 11 Sep 2008 14:32:08 GMT (302kb)

Title: Antiferromagnetic Order of Strongly Interacting Fermions in a Trap:

Real-Space Dynamical Mean-Field Analysis

Authors: M. Snoek, I. Titvinidze, C. Toke, K. Byczuk, and W. Hofstetter

Categories: cond-mat.str-el

Comments: 4 pages 5 figures, published version

Journal-ref: New J. Phys. 10 (2008) 093008

DOI: 10.1088/1367-2630/10/9/093008

\\ ( http://arxiv.org/abs/0802.3211 , 302kb)

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arXiv:0803.4419

replaced with revised version Thu, 11 Sep 2008 13:27:00 GMT (100kb)

Title: The role of interactions in spin-polarised atomic Fermi gases at

unitarity

Authors: A. Recati, C. Lobo, S. Stringari

Categories: cond-mat.other

Comments: Revisitedc version accepted for pubblication. 1 figure added, 1

figure correted, typos corrected, references updated

Journal-ref: Phys. Rev. A 78, 023633 (2008)

\\ ( http://arxiv.org/abs/0803.4419 , 100kb)

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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 Mon Oct 13 2008 - 09:06:24 EST

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