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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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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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