The following message was sent to the matts_arxiv list by Matthew Davis <mdavis_at_physics.uq.edu.au>
This week there were 31 new preprints and 9 replacements.
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arXiv:0901.2425
Date: Fri, 16 Jan 2009 09:06:04 GMT (220kb)
Title: Green-function method in the theory of ultraslow electromagnetic waves
in an ideal gas with Bose-Einstein condensates
Authors: Yurii Slyusarenko and Andrii Sotnikov
Categories: cond-mat.stat-mech cond-mat.other
Comments: 15 pages, 6 figures
Journal-ref: Phys. Rev. A 78, 2008, 053622
DOI: 10.1103/PhysRevA.78.053622
\\
We propose a microscopic approach describing the interaction of an ideal gas
of hydrogenlike atoms with a weak electromagnetic field. This approach is based
on the Green-function formalism and an approximate formulation of the method of
second quantization for quantum many-particle systems in the presence of bound
states of particles. The dependencies of the propagation velocity and damping
rate of electromagnetic pulses on the microscopic characteristics of the system
are studied for a gas of hydrogenlike atoms. For a Bose-Einstein condensate of
alkali-metal atoms we find the conditions when the electromagnetic waves of
both the optical and microwave regions are slowed. In the framework of the
proposed approach, the influence of an external homogeneous and static magnetic
field on the slowing phenomenon is studied.
\\ ( http://arxiv.org/abs/0901.2425 , 220kb)
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arXiv:0901.2487
Date: Fri, 16 Jan 2009 14:05:23 GMT (301kb)
Title: New superfluid states - a first glance
Authors: George Kastrinakis
Categories: cond-mat.supr-con cond-mat.str-el
Comments: First report on the new superfluid states
\\
We introduce two new fermionic variational wavefunctions, which sustain
superfluidity. Applications include quark matter, nuclei, neutron stars and the
high temperature superconductors. Spin up and down fermions are, in principle,
inequivalent, and a normal fluid component coexists with the superfluid one. A
wider class of Hamiltonians than sheer Bardeen-Cooper-Schrieffer (BCS) type,
comprising hybridization and interaction between different fermion species, can
be treated exactly, as in the well known manner of BCS theory. A simple model
of interacting electrons in a lattice yields a ratio of the maximum
superconducting gap to the transition temperature in the range 3 to 6, as
compared to the typical isotropic s-wave BCS value of 1.76. However, the BCS
solutions are dominant for this simple model.
\\ ( http://arxiv.org/abs/0901.2487 , 301kb)
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arXiv:0901.2496
Date: Fri, 16 Jan 2009 14:42:34 GMT (143kb)
Title: Four lectures on computational statistical physics
Authors: Werner Krauth
Categories: cond-mat.stat-mech
Comments: 32 pages, Lectures given at the 2008 Les Houches Summer School "Exact
methods in low-dimensional physics and quantum computing"
\\
In my lectures at the Les Houches Summer School 2008, I discussed central
concepts of computational statistical physics, which I felt would be accessible
to the very cross-cultural audience at the school.
I started with a discussion of sampling, which lies at the heart of the Monte
Carlo approach. I specially emphasized the concept of perfect sampling, which
offers a synthesis of the traditional direct and Markov-chain sampling
approaches. The second lecture concerned classical hard-sphere systems, which
illuminate the foundations of statistical mechanics, but also illustrate the
curious difficulties that beset even the most recent simulations. I then moved
on, in the third lecture, to quantum Monte Carlo methods, that underly much of
the modern work in bosonic systems. Quantum Monte Carlo is an intricate
subject. Yet one can discuss it in simplified settings (the single-particle
free propagator, ideal bosons) and write direct-sampling algorithms for the two
cases in two or three dozen lines of code only. These idealized algorithms
illustrate many of the crucial ideas in the field. The fourth lecture attempted
to illustrate aspects of the unity of physics as realized in the Ising model
simulations of recent years.
More details on what I discussed in Les Houches, and wrote up (and somewhat
rearranged) here, can be found in my book, "Statistical Mechanics: Algorithms
and Computations", as well as in recent papers. Computer programs are available
for download and perusal at the book's web site www.smac.lps.ens.fr.
\\ ( http://arxiv.org/abs/0901.2496 , 143kb)
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arXiv:0901.2512
Date: Fri, 16 Jan 2009 16:03:09 GMT (73kb)
Title: Correlations in a two-dimensional Bose gas with long range interactions
Authors: B. Laikhtman and R. Rapaport
Categories: cond-mat.stat-mech
Comments: 11 pages including 2 figures
\\
We study the correlations of two-dimensional dipolar excitons in coupled
quantum wells with a dipole -- dipole repulsive interaction. We show that at
low concentrations, the Bose degeneracy of the excitons is accompanied by
strong multi-particle correlations and the system behaves as a Bose liquid. At
high concentration the particles interaction suppresses quantum coherence and
the system behaves similar to a classical liquid down to a temperature lower
than typical for a Bose gas. We evaluate the interaction energy per particle
and the resulting blue shift of the exciton luminescence that is a direct tool
to measure the correlations. This theory can apply to other systems of bosons
with extended interaction.
\\ ( http://arxiv.org/abs/0901.2512 , 73kb)
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arXiv:0901.2553
Date: Fri, 16 Jan 2009 19:21:37 GMT (11kb)
Title: The peculiarities of Bose-condensation of quasiparticles
Authors: A.I. Bugrij and V.M. Loktev
Categories: cond-mat.stat-mech
Comments: 10 pages
\\
An attempt is made to consider the difference between the proccesses of the
Bose-Einstein condensation of particles and quasiparticles. An equation for
particle number of the Bose-condensate as a function of the total number of
particles in the system is obtained. This equation is also written for the
caseof quasiparticles with taking into account their creation by pumping and
the existence ofequilibriumthermal excitations in the system. From the analysis
of both these equations the chemical potential of pumped quasiparticles and
their number in the condensate as a function of pumping intensity is found. It
is shown that for low energy quasiparticles the proccess of Bose-condensation
begins and proceeds at arbitrary temperatures high enough included.
\\ ( http://arxiv.org/abs/0901.2553 , 11kb)
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arXiv:0901.2549
Date: Fri, 16 Jan 2009 19:10:09 GMT (279kb)
Title: Atom trapping in an interferometrically generated bottle beam trap
Authors: L. Isenhower, W. Williams, A. Dally, and M. Saffman
Categories: physics.optics physics.atom-ph
Comments: 3 figures
\\
We demonstrate an optical bottle beam trap created by interfering two
fundamental Gaussian beams with different waists. The beams are derived from a
single laser source using a Mach-Zehnder interferometer whose arms have unequal
magnifications. Destructive interference of the two beams from the Mach-Zehnder
leads to a three dimensional intensity null at the mutual focus of the beams.
We demonstrate trapping of cold Cesium atoms in a blue detuned bottle beam
trap.
\\ ( http://arxiv.org/abs/0901.2549 , 279kb)
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arXiv:0901.2576
Date: Fri, 16 Jan 2009 21:14:04 GMT (329kb)
Title: Two-dimensional fermionic superfluids, pairing instability and vortex
liquids in the absence of time reversal symmetry
Authors: Predrag Nikolic
Categories: cond-mat.supr-con cond-mat.str-el
Comments: 11 pages, 3 figures
\\
We consider a generic two-dimensional system of fermionic particles with
attractive interactions and no disorder. If time-reversal symmetry is absent,
it is possible to obtain incompressible insulating states in addition to the
superfluid at zero temperature. The superfluid-insulator phase transition is
found to be second order in type-II systems using a perturbative analysis of
Cooper pairing instability in quantum Hall states of unpaired fermions. We
obtain the pairing phase diagram as a function of chemical potential (density)
and temperature. However, a more careful analysis presented here reveals that
the pairing quantum phase transition is always preempted by another transition
into a strongly correlated normal state which retains Cooper pairing and cannot
be smoothly connected to the quantum Hall state of unpaired fermions. Such a
normal phase can be qualitatively viewed as a liquid of vortices, although it
may acquire conventional broken symmetries. Even if it did not survive at
finite temperatures its influence would be felt through strong quantum
fluctuations below a crossover temperature scale. These conclusions directly
apply to fermionic ultra-cold atom systems near unitarity, but are likely
relevant for the properties of other strongly correlated superfluids as well,
including high temperature superconductors.
\\ ( http://arxiv.org/abs/0901.2576 , 329kb)
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arXiv:0901.2755
Date: Mon, 19 Jan 2009 19:59:23 GMT (451kb)
Title: Scale invariant thermodynamics of a toroidally trapped Bose gas
Authors: A. S. Bradley
Categories: cond-mat.stat-mech
Comments: 9 pages, 3 figures, APS format
\\
We consider a system of bosonic atoms in an axially symmetric harmonic trap
augmented with a Gaussian optical potential. Focussing on the case of blue
detuning we determine the ideal gas thermodynamics of the system for
configurations ranging from the harmonic trap to the toroidal regime. For large
tori the ideal gas thermodynamics of the system are found to be independent of
toroidal radius. In considering corrections to the scale invariant transition
temperature, we find that the first order interaction shift is the dominant
effect in the thermodynamic limit, and is also scale invariant. We also
consider adiabatic loading from the harmonic to toroidal trap configuration,
which we show to have only a small effect on the condensate fraction for the
ideal gas, indicating that loading into the scale invariant regime may be
experimentally practical.
\\ ( http://arxiv.org/abs/0901.2755 , 451kb)
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arXiv:0901.2807
Date: Mon, 19 Jan 2009 10:41:27 GMT (444kb)
Title: Occupation Statistics of a BEC for a Driven Landau-Zener Crossing
Authors: Katrina Smith-Mannschott, Maya Chuchem, Moritz Hiller, Tsampikos
Kottos, Doron Cohen
Categories: cond-mat.other
Comments: 4 pages, 5 figures
\\
We consider an atomic Bose-Einstein condensate (BEC) loaded in a biased
double-well trap with tunneling rate $K$ and inter-atomic interaction $U$. The
BEC is prepared such that all $N$ atoms are in the left well. We drive the
system by sweeping the potential difference $\epsilon$ between the two wells.
Depending on the interaction $u=NU/K$, and the sweep rate $\dot{\epsilon}$, we
distinguish three dynamical regimes: {\em adiabatic}, {\em diabatic}, and {\em
sudden} and consider the occupation statistics of the final state. The analysis
goes beyond mean-field theory and is complemented by a semiclassical picture.
\\ ( http://arxiv.org/abs/0901.2807 , 444kb)
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arXiv:0901.2836
Date: Mon, 19 Jan 2009 12:40:17 GMT (9kb)
Title: Entanglement generation by collisions of quantum solitons
Authors: Maciej Lewenstein and Boris A. Malomed
Categories: cond-mat.other
\\
We present general analytic expressions describing generation of the
entanglement in collisions of initially uncorrelated quantum solitons. The
results, obtained by means of the Born approximation, are valid for both
integrable and non-integrable quasi-one-dimensional systems supporting soliton
states.
\\ ( http://arxiv.org/abs/0901.2836 , 9kb)
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arXiv:0901.2842
Date: Mon, 19 Jan 2009 13:00:57 GMT (636kb)
Title: Chandrasekhar-Clogston limit and phase separation in Fermi mixtures at
Unitarity
Authors: I. Bausmerth, A. Recati and S. Stringari
Categories: cond-mat.other
Comments: 7 pages, 6 figures
\\
Using many-body results available from diagrammatic and {\it ab initio} Monte
Carlo calculations we analyze the phase diagram $\mu=(\mua+\mda)/2$ versus
$h=(\mua-\mda)/2$ of a unitary Fermi gas at zero temperature with population
imbalance and unequal masses. We identify different regions where the gas is
superfluid, partially polarized or fully polarized and determine the
corresponding coexistence conditions. The asymmetry in the phase diagram,
caused by the mass imbalance, and its effect on the Chandrasekhar-Clogston
limit for the critical polarization are explicitly discussed. The equation of
state of the superfluid and normal phases is employed, within the local density
approximation, to predict novel phase separated configurations in the presence
of harmonic trapping potentials.
\\ ( http://arxiv.org/abs/0901.2842 , 636kb)
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arXiv:0901.2890
Date: Mon, 19 Jan 2009 16:30:04 GMT (448kb)
Title: Manipulation of quantum particles in rapidly oscillating potentials by
inducing phase hops
Authors: Armin Ridinger (LKB - Lhomond), Christoph Weiss (LKB - Lhomond)
Categories: cond-mat.other quant-ph
Comments: 7 pages, 4 figures
Journal-ref: Physical Review A: Atomic, Molecular and Optical Physics 79, 1
(2009) 013414
DOI: 10.1103/PhysRevA.79.013414
\\
Analytical calculations show that the mean-motion of a quantum particle
trapped by a rapidly oscillating potential can be significantly manipulated by
inducing phase hops, i.e., by instantaneously changing the potential's phase. A
phase hop can be visualized as being the result of a collision with an
imaginary particle which can be controlled. Several phase hops can have
accumulating effects on the particle's mean-motion, even if they transform the
particle's Hamiltonian into its initial one. The theoretical predictions are
verified by numerical simulations for the one-dimensional Paul-trap.
\\ ( http://arxiv.org/abs/0901.2890 , 448kb)
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arXiv:0901.2783
Date: Mon, 19 Jan 2009 08:44:18 GMT (2231kb,D)
Title: Continuous Variable Entanglement and Squeezing of Orbital Angular
Momentum States
Authors: Mikael Lassen, Gerd Leuchs, Ulrik L. Andersen
Categories: quant-ph
Comments: 4 pages, 4 figures
\\
We report the first experimental characterization of the first-order
continuous variable orbital angular momentum states. Using a spatially
non-degenerate optical parametric oscillator (OPO) we produce quadrature
entanglement between the two first-order Laguerre-Gauss modes. The family of
OAM modes is mapped on an orbital Poincare sphere, and the modes position on
the sphere is spanned by the three orbital parameters. Using the non-degenerate
OPO we produce squeezing of these parameters, and as an illustration, we
reconstruct the "cigar-shaped" uncertainty volume on the orbital Poincare
sphere.
\\ ( http://arxiv.org/abs/0901.2783 , 2231kb)
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arXiv:0901.2943
Date: Mon, 19 Jan 2009 22:08:28 GMT (25kb,D)
Title: Ground state energy of the two-dimensional weakly interacting Bose gas:
First correction beyond Bogoliubov theory
Authors: Christophe Mora, Yvan Castin
Categories: cond-mat.stat-mech
Comments: 4 pages, 1 figure
\\
We consider the grand potential $\Omega$ of a two-dimensional weakly
interacting homogeneous Bose gas at zero temperature. Building on a
number-conserving Bogoliubov method for a lattice model in the grand canonical
ensemble, we calculate the next order term as compared to the Bogoliubov
prediction, in a systematic expansion of $\Omega$ in powers of the parameter
measuring the weakness of the interaction. Our prediction is in very good
agreement with recent Monte Carlo calculations.
\\ ( http://arxiv.org/abs/0901.2943 , 25kb)
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arXiv:0901.2945
Date: Mon, 19 Jan 2009 22:22:51 GMT (753kb)
Title: Theory of the Normal/Superfluid interface in population imbalanced Fermi
gases
Authors: Stefan K. Baur (Cornell), Sourish Basu (Cornell), Theja N. De Silva
(Binghamton), Erich J. Mueller (Cornell)
Categories: cond-mat.other
Comments: 15 pages, 9 figures (13 subfigures)
\\
We present a series of theoretical studies of the boundary between a
superfluid and normal region in a partially polarized gas of strongly
interacting fermions. We present mean-field estimates of the surface energy in
this boundary as a function of temperature and scattering length. We discuss
the structure of the domain wall, and use a previously introduced
phenomonological model to study its influence on experimental observables.
\\ ( http://arxiv.org/abs/0901.2945 , 753kb)
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arXiv:0901.3048
Date: Tue, 20 Jan 2009 12:56:09 GMT (25kb)
Title: Weakly Interacting Bose Mixtures at Finite Temperature
Authors: Bert Van Schaeybroeck
Categories: cond-mat.other cond-mat.stat-mech
Comments: 4 pages, 2 figures
\\
Motivated by the recent experiments on Bose-Einstein mixtures with tunable
interactions we study repulsive weakly interacting Bose mixtures at finite
temperature. We obtain phase diagrams using Hartree-Fock theory which are
directly applicable to experimentally trapped systems. Almost all features of
the diagrams can be characterized using simple physical insights. Our work
reveals two surprising effects which are dissimilar to a system at zero
temperature. First of all, no pure phases exist, that is, at each point in the
trap, particles of both species are always present. Second, even for very weak
interspecies repulsion when full mixing is expected, condensate particles of
both species may be present in a trap without them being mixed.
\\ ( http://arxiv.org/abs/0901.3048 , 25kb)
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arXiv:0901.3091
Date: Tue, 20 Jan 2009 16:35:09 GMT (178kb)
Title: Quantum polarization spectroscopy of correlations in attractive
fermionic gases
Authors: T. Roscilde, M. Rodriguez, K. Eckert, O. Romero-Isart, M. Lewenstein,
E. Polzik and A. Sanpera
Categories: cond-mat.str-el cond-mat.mes-hall
Comments: 16 pages, 9 figures
\\
We show how spin-spin correlations, detected in a non-destructive way via
spatially resolved quantum polarization spectroscopy, strongly characterize
various phases realized in trapped ultracold fermionic atoms. Polarization
degrees of freedom of the light couple to spatially resolved components of the
atomic spin. In this way quantum fluctuations of matter are faithfully mapped
onto those of light. In particular we demonstrate that quantum spin
polarization spectroscopy provides a direct method to detect the
Fulde-Ferrell-Larkin-Ovchinnikov phase realized in a one-dimensional imbalanced
Fermi system.
\\ ( http://arxiv.org/abs/0901.3091 , 178kb)
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arXiv:0901.2956
Date: Mon, 19 Jan 2009 23:45:33 GMT (72kb)
Title: Synchronous Quantum Memories with Time-symmetric Pulses
Authors: Q. Y. He, M. D. Reid, and P. D. Drummond
Categories: quant-ph
Comments: 4 pages, 4 figures
\\
We propose a dynamical approach to quantum memories using a synchronous
oscillator-cavity model, in which the coupling is shaped in time to provide the
optimum interface to a symmetric input pulse. This overcomes the known
difficulties of achieving high quantum input-output fidelity with storage times
long compared to the input signal duration. Our generic model is applicable to
any linear storage medium ranging from a superconducting device to an atomic
medium. We show that with temporal modulation of coupling and/or detuning, it
is possible to mode-match to time-symmetric pulses that have identical pulse
shapes on input and output.
\\ ( http://arxiv.org/abs/0901.2956 , 72kb)
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arXiv:0901.3105
Date: Tue, 20 Jan 2009 17:44:22 GMT (495kb)
Title: Prospects for a mHz-linewidth laser
Authors: D. Meiser, Jun Ye, D. R. Carlson, and M. J. Holland
Categories: quant-ph
Comments: 5 pages, 3 figures
\\
Optical atomic clocks based on ultracold alkaline-earth atoms confined in a
lattice potential are competitive with the most stable and accurate time and
frequency standards. The main bottleneck that prevents these clocks from
achieving still better precision is the linewidth of the laser used to
interrogate the clock transition. We propose to utilize the ultra-narrow atomic
transition by making the atoms emit photons on that line collectively into the
mode of a high Q-resonator in a laser-like fashion. A power level of order
$10^{-12}$ W is possible, sufficient for phase-locking a slave optical local
oscillator. We find that the linewidth of the radiation can be on the order of
or even narrower than that of the clock transition due to collective effects.
Achieving this major breakthrough will improve the stability of the best clocks
by two orders of magnitude.
\\ ( http://arxiv.org/abs/0901.3105 , 495kb)
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arXiv:0901.3129
Date: Tue, 20 Jan 2009 19:52:15 GMT (116kb)
Title: Feshbach resonances in ultracold atom-molecule collisions
Authors: A. Simoni, J-M. Launay, P. Soldan
Categories: quant-ph
Comments: 7 pages, 6 figures
\\
We investigate the presence of Feshbach resonances in ultracold
alkali-dialkali reactive collisions. Quantum scattering calculations are
performed on a new Na_3 quartet potential energy surface. An analysis of
scattering features is performed through a systematic variation of the
nonadditive three-body interaction potential. Our results should provide useful
information for interpreting future atom-molecule collision experiments.
\\ ( http://arxiv.org/abs/0901.3129 , 116kb)
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arXiv:0901.2960
Date: Mon, 19 Jan 2009 23:59:00 GMT (1533kb)
Title: Two-Photon Dichroic Atomic Vapor Laser Lock Using Electromagnetically
Induced Transparency and Absorption
Authors: F. E. Becerra, R. T. Willis, S. L. Rolston, L. A. Orozco
Categories: physics.optics physics.atom-ph
Comments: 6 pages, 8 figures
\\
We demonstrate a technique to lock the frequency of a laser to a two-photon
transition of Rb vapor in the presence of a weak magnetic field. We use a
ladder configuration from specific hyperfine sublevels of the 5S 1/2, 5P 3/2,
and 5D 5/2 levels. This transition shows Electromagnetically Induced
Transparency and Absorption processes. The error signal comes from the
difference in the transparency or absorption felt by the two orthogonal
polarizations of the probe beam. A simplified model is in good quantitative
agreement with the observed signals for the experimental parameters. We have
used this technique to lock the frequency of the laser up to 1.5 GHz off atomic
resonance.
\\ ( http://arxiv.org/abs/0901.2960 , 1533kb)
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arXiv:0901.3148
Date: Tue, 20 Jan 2009 21:07:29 GMT (112kb)
Title: Heavy-Light Fermion Mixtures at Unitarity
Authors: Alexandros Gezerlis, S. Gandolfi, K. E. Schmidt, J. Carlson
Categories: cond-mat.other
Comments: 4 pages, 4 figures
\\
We investigate pairing between unequal-mass fermions in the unitary regime
for a mass ratio corresponding to a 6Li-40K mixture. We show that the fully
paired superfluid state is nearly independent of the mass ratio; the
ground-state energy and the average light and heavy particle excitation
spectrum change very little. However, in the majority light system, the
polarized superfluid is close to stability compared to a phase separated state.
For a majority of heavy particles, we find an energy minimum for a normal state
with a ratio of ~ 3:1 heavy to light particles. A slight increase in attraction
to kF*a ~ 2.5 renders the system unstable. A cold unpolarized system in a
harmonic trap at unitarity should phase separate into three regions: a normal
state with a large heavy to light ratio in the center, followed by a shell of
fully paired superfluid in the middle and either a polarized superfluid or a
nearly fully polarized normal state in the exterior.
\\ ( http://arxiv.org/abs/0901.3148 , 112kb)
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arXiv:0901.3152
Date: Tue, 20 Jan 2009 21:26:06 GMT (142kb)
Title: Phase-imprint induced domain formations and spin dynamics in spinor
condensates
Authors: Chengjun Tao and Qiang Gu
Categories: cond-mat.other cond-mat.supr-con
Comments: 5 pages, 5 figures, to appear in Phys. Rev. A
\\
We demonstrate that certain domain structures can be created both in ferro-
and antiferro-magnetic spinor condensates if the initial phase is spatially
modulated. Meanwhile, spin dynamics of the condensate with modulated phases
exhibits exotic features in comparison with those of a condensate with a
uniform phase. We expect that these phenomena could be observed experimentally
using a phase-imprinting method.
\\ ( http://arxiv.org/abs/0901.3152 , 142kb)
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arXiv:0901.3285
Date: Wed, 21 Jan 2009 14:45:36 GMT (393kb)
Title: Population imbalanced Fermi gases in quasi two dimensions
Authors: Theja N. De Silva
Categories: cond-mat.other
Comments: 6 pages and 5 figures
\\
We study population imbalanced Fermi gases in quasi two dimensions using a
mean field theory. At zero temperature, we derive an analytic equation for the
gap parameter together with analytical expressions for the free energy and
density for weakly coupled layers in the entire Bardeen, Cooper and
Schrieffer-Bose Einstein condensation (BCS-BEC) crossover region. By
investigating the effect of weak atom tunneling between layers, we then map out
the phase diagram of the system. We find that the superfluid phase stabilizes
as one decreases the atom tunneling between layers. This allows one to control
the first order superfluid-normal phase transition by tuning a single
experimental parameter. At Finite temperatures, we use a Landau-Ginzberg
functional approach to investigate the possibility of spatially inhomogeneous
Fulde-Ferrel-Larkin-Ovchinnikov (FFLO) phase in the weak coupling BCS limit
near the tricritical point of spatially homogenous superfluid, FFLO, and normal
phases. We find that the normal-FFLO phase transition is first order as oppose
to the zero temperature theories.
\\ ( http://arxiv.org/abs/0901.3285 , 393kb)
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arXiv:0901.3345
Date: Wed, 21 Jan 2009 20:50:35 GMT (470kb)
Title: Quantum dynamics of instability-induced pulsations of a Bose-Einstein
condensate in an optical lattice
Authors: Uttam Shrestha, Juha Javanainen, and Janne Ruostekoski
Categories: cond-mat.other
\\
We study the dynamics of a Bose-Einstein condensate in a one-dimensional
optical lattice in the limit of weak atom-atom interactions, including an
approximate model for quantum fluctuations. A pulsating dynamical instability
in which atoms periodically collect together and subsequently disperse back
into the initial homogeneous state may occur in the time evolution. We take
into account the quantum fluctuations within the truncated Wigner
approximation. We observe that the quasiperiodic behavior still persists for a
single realization that represents a typical experimental outcome, but ensemble
averages show various manifestations of quantum fluctuations. Quantum effects
become more prominent when the effective interaction strength is increased.
\\ ( http://arxiv.org/abs/0901.3345 , 470kb)
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arXiv:0901.3309
Date: Wed, 21 Jan 2009 16:38:48 GMT (399kb)
Title: Determining the Minimum Uncertainty State of Nonclassical Light
Authors: C. Gabriel, J. Janousek, and H.-A. Bachor
Categories: quant-ph
\\
Squeezing experiments which are capable of creating a minimum uncertainty
state during the nonlinear process, for example optical parametric
amplification, are commonly used to produce light far below the quantum noise
limit. This report presents a method with which one can characterize this
minimum uncertainty state and gain valuable knowledge of the experimental
setup.
\\ ( http://arxiv.org/abs/0901.3309 , 399kb)
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arXiv:0901.3335
Date: Wed, 21 Jan 2009 19:23:31 GMT (374kb)
Title: Quantum Optics with Quantum Gases
Authors: Igor B. Mekhov and Helmut Ritsch
Categories: quant-ph
Comments: to be published in Laser Physics (2009)
\\
Quantum optics with quantum gases represents a new field, where the quantum
nature of both light and ultracold matter plays equally important role. Only
very recently this ultimate quantum limit of light-matter interaction became
feasible experimentally. In traditional quantum optics, the cold atoms are
considered classically, whereas, in quantum atom optics, the light is used as
an essentially classical axillary tool. On the one hand, the quantization of
optical trapping potentials can significantly modify many-body dynamics of
atoms, which is well-known only for classical potentials. On the other hand,
atomic fluctuations can modify the properties of the scattered light.
\\ ( http://arxiv.org/abs/0901.3335 , 374kb)
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arXiv:0901.3303
Date: Wed, 21 Jan 2009 16:08:22 GMT (119kb)
Title: Atom chips and one-dimensional Bose gases
Authors: Isabelle Bouchoule (LCFIO), N. J. Van Druten, Chris Westbrook (LCFIO)
Categories: physics.atom-ph
\\
In this review article, we describe the studies of 1D gases realised on
atom-chip experiments.
\\ ( http://arxiv.org/abs/0901.3303 , 119kb)
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arXiv:0901.3438
Date: Thu, 22 Jan 2009 09:44:21 GMT (47kb)
Title: Zero Sound and First Sound in a Disk-Shaped Normal Fermi gas
Authors: Giovanni Mazzarella, Luca Salasnich, Flavio Toigo
Categories: cond-mat.other
Comments: 9 pages, 5 figures, editorially approved for publication on Phys.
Rev. A
\\
We study the zero sound and the first sound in a dilute and ultracold
disk-shaped normal Fermi gas with a strong harmonic confinement along the axial
direction and uniform in the two planar directions. Working at zero temperature
we calculate the chemical potential $\mu$ of the fermionic fluid as a function
of the uniform planar density $\rho$ and find that $\mu$ changes its slope in
correspondence to the filling of harmonic axial modes (shell effects). Within
the linear response theory, and under the random phase approximation, we
calculate the velocity $c^{0}_s$ of the zero sound. We find that also $c^0_s$
changes its slope in correspondence of the filling of the harmonic axial modes
and that this effect depends on the Fermi-Fermi scattering length $a_F$. In the
collisional regime, we calculate the velocity $c_s$ of first sound showing that
$c_s$ displays jumps at critical densities fixed by the scattering length
$a_F$. Finally, we discuss the experimental achievability of these zero sound
and first sound waves with ultracold alkali-metal atoms.
\\ ( http://arxiv.org/abs/0901.3438 , 47kb)
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arXiv:0901.3439
Date: Thu, 22 Jan 2009 09:44:29 GMT (768kb)
Title: An Introduction to the Quantum Theory of Nonlinear Optics
Authors: Mark Hillery
Categories: quant-ph
Comments: 80 pages,
Journal-ref: Acta Physica Slovaca 59, No.1, 1-80 (2009)
\\
This article is provides an introduction to the quantum theory of optics in
nonlinear dielectric media. We begin with a short summary of the classical
theory of nonlinear optics, that is nonlinear optics done with classical
fields. We then discuss the canonical formalism for fields and its
quantization. This is applied to quantizing the electromagnetic field in free
space. The definition of a nonclassical state of the electromagnetic field is
presented, and several examples are examined. This is followed by a brief
introduction to entanglement in the context of field modes. The next task is
the quantization of the electromagnetic field in an inhomogeneous, linear
dielectric medium. Before going on to field quantization in nonlinear media, we
discuss a number of commonly employed phenomenological models for quantum
nonlinear optical processes. We then quantize the field in both nondispersive
and dispersive nonlinear media. Flaws in the most commonly used methods of
accomplishing this task are pointed out and discussed. Once the quantization
has been completed, it is used to study a multimode theory of parametric down
conversion and the propagation of quantum solitons.
\\ ( http://arxiv.org/abs/0901.3439 , 768kb)
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\\
arXiv:0901.3355
Date: Thu, 22 Jan 2009 19:42:34 GMT (366kb)
Title: Bose-Einstein Condensation of Electrons in Doubly Excited States of
Heliumlike Atoms
Authors: V.V.Kavera
Categories: physics.atom-ph physics.plasm-ph
Comments: 4 pages
\\
The author supposes a capability of transition doubly excited configurations
of separate atoms to a superconducting state. The conditions of this transition
are determined and the experiments for its detection are offered. The
capability of join of superconducting atoms in a superconducting condensate is
considered. The capability of spontaneous formation of similar condensates in
atmospheres of the Earth and Sun is considered.
\\ ( http://arxiv.org/abs/0901.3355 , 366kb)
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The replacements:
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arXiv:0807.1450
replaced with revised version Thu, 15 Jan 2009 22:21:01 GMT (343kb)
Title: Fermionic superfluid properties in a one-dimensional optical lattice
Authors: Theja N. De Silva
Categories: cond-mat.other
Comments: 6 pages, 5 figures, Updated with the published version
Journal-ref: Phys. Rev. A 79, 013612 (2009)
DOI: 10.1103/PhysRevA.79.013612
\\ ( http://arxiv.org/abs/0807.1450 , 343kb)
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arXiv:0807.3067
replaced with revised version Fri, 16 Jan 2009 16:21:31 GMT (170kb)
Title: Ultracold atom spin field effect transistors
Authors: J. Y. Vaishnav, Julius Ruseckas, Charles W. Clark, Gediminas
Juzeliunas
Categories: cond-mat.mes-hall cond-mat.other physics.atom-ph quant-ph
Journal-ref: Phys. Rev. Lett. 101, 265302 (2008)
DOI: 10.1103/PhysRevLett.101.265302
\\ ( http://arxiv.org/abs/0807.3067 , 170kb)
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arXiv:0802.1222
replaced with revised version Thu, 15 Jan 2009 22:21:13 GMT (31kb)
Title: S-wave and p-wave scattering in a cold gas of Na and Rb atoms
Authors: Henni Ouerdane and Michael J. Jamieson
Categories: physics.atom-ph
Comments: The article contains additional material and data (see abstract)
\\ ( http://arxiv.org/abs/0802.1222 , 31kb)
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arXiv:0805.2571
replaced with revised version Sat, 17 Jan 2009 15:44:29 GMT (741kb)
Title: Superfluid Bose gas in two dimensions
Authors: S. Floerchinger and C. Wetterich
Categories: cond-mat.supr-con
Comments: 10 pages, 12 figures, reference added
Journal-ref: Phys. Rev. A 79, 013601 (2009)
DOI: 10.1103/PhysRevA.79.013601
\\ ( http://arxiv.org/abs/0805.2571 , 741kb)
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arXiv:0809.1675
replaced with revised version Sat, 17 Jan 2009 15:53:43 GMT (314kb)
Title: Functional renormalization for trion formation in ultracold fermion
gases
Authors: S. Floerchinger, R. Schmidt, S. Moroz, and C. Wetterich
Categories: cond-mat.supr-con
Comments: 9 pages, 4 figures, minor changes, reference added
Journal-ref: Phys. Rev. A 79, 013603 (2009)
DOI: 10.1103/PhysRevA.79.013603
\\ ( http://arxiv.org/abs/0809.1675 , 314kb)
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arXiv:0806.2812
replaced with revised version Tue, 20 Jan 2009 16:35:18 GMT (121kb)
Title: Quantum Phase Diagram of Bosons in Optical Lattices
Authors: F. E. A. dos Santos and A. Pelster
Categories: cond-mat.stat-mech
Journal-ref: Physical Review A 79, 013614 (2009)
\\ ( http://arxiv.org/abs/0806.2812 , 121kb)
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arXiv:0712.2951
replaced with revised version Thu, 22 Jan 2009 06:14:32 GMT (569kb)
Title: Discrete chaotic states of a Bose-Einstein condensate
Authors: Wenhua Hai, Shiguang Rong, Qianquan Zhu
Categories: cond-mat.other
Comments: 7 pages, 5 figures
Journal-ref: Phys. Rev. E 78, 066214 (2008)
\\ ( http://arxiv.org/abs/0712.2951 , 569kb)
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arXiv:0808.1898
replaced with revised version Thu, 22 Jan 2009 20:27:22 GMT (161kb)
Title: Phonon-induced artificial magnetic fields
Authors: Alexander Klein and Dieter Jaksch
Categories: quant-ph cond-mat.other
Comments: 6 pages, 4 figures
Journal-ref: EPL, 85 (2009) 13001
DOI: 10.1209/0295-5075/85/13001
\\ ( http://arxiv.org/abs/0808.1898 , 161kb)
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arXiv:0810.2028
replaced with revised version Thu, 22 Jan 2009 20:42:12 GMT (2338kb)
Title: Structure formation during the collapse of a dipolar atomic
Bose-Einstein condensate
Authors: N.G. Parker, C. Ticknor, A.M. Martin and D.H.J. O'Dell
Categories: cond-mat.other
Comments: In this version (the published version) we have slightly rewritten
the manuscript in places and have corrected some typos. 15 pages and 13
figures
Journal-ref: N. G. Parker, C. Ticknor, A. M. Martin and D. H. J. O'Dell, Phys.
Rev. A 79, 013617 (2009)
\\ ( http://arxiv.org/abs/0810.2028 , 2338kb)
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Till next time,
Matt.
--
=========================================================================
Dr M. J. Davis, Associate Professor in Physics
School of Mathematics and Physics, ph : +61 7 334 69824
The University of Queensland, fax : +61 7 336 51242
Brisbane, QLD 4072, mdavis_at_physics.uq.edu.au
Australia. www.physics.uq.edu.au/people/mdavis/
=========================================================================
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http://www.physics.uq.edu.au/people/mdavis/matts_arXiv/
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Received on Fri May 01 2009 - 15:51:04 EST
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