[Matts-arxiv] Matt's arXiv selection: week ending 31 July 2009

From: Matthew Davis <mdavis_at_physics.uq.edu.au>
Date: Fri, 11 Sep 2009 19:26:35 +1000

Dear subscribers,

This was a big week: 44 new preprints and 24 replacements.

arXiv:0907.1267 (*cross-listing*)
Date: Tue, 7 Jul 2009 17:18:12 GMT (10kb)

Title: On the speed of fluctuations around thermodynamic equilibrium
Authors: Noah Linden, Sandu Popescu, Anthony J Short, Andreas Winter
Categories: quant-ph cond-mat.stat-mech
   We study the speed of fluctuation of a quantum system around its
thermodynamic equilibrium state, and show that the speed will be extremely
small for almost all times in typical thermodynamic cases. The setting
considered here is that of a quantum system couples to a bath, both jointly
described as a closed system. This setting, is the same as the one considered
in [N. Linden et al., Phys. Rev. E 79:061103 (2009)] and the ``thermodynamic
equilibrium state'' refers to a situation that includes the usual thermodynamic
equilibrium case, as well as far more general situations.
\\ ( http://arxiv.org/abs/0907.1267 , 10kb)
arXiv:0907.1587 (*cross-listing*)
Date: Thu, 9 Jul 2009 15:32:47 GMT (529kb)

Title: Continuum multi-physics modeling with scripting languages: the Nsim
   simulation compiler prototype for classical field theory
Authors: Thomas Fischbacher and Hans Fangohr
Categories: physics.comp-ph cond-mat.mes-hall cs.DC
Comments: 50 pages, 5 figures
   We demonstrate that for a broad class of physical systems that can be
described using classical field theory, automated runtime translation of the
physical equations to parallelized finite-element numerical simulation code is
feasible. This allows the implementation of multiphysics extension modules to
popular scripting languages (such as Python) that handle the complete
specification of the physical system at script level. We discuss two example
applications that utilize this framework: the micromagnetic simulation package
"Nmag" as well as a short Python script to study morphogenesis in a
reaction-diffusion model.
\\ ( http://arxiv.org/abs/0907.1587 , 529kb)
Date: Thu, 23 Jul 2009 21:53:15 GMT (362kb)

Title: EDM searches based on alkali or alkaline earth bearing molecules
Authors: Edmund R. Meyer and John L. Bohn
Categories: physics.atom-ph
Comments: 6 pages, two column format, 5 figures, submitted to Phys. Rev. A
   We introduce four new molecules -- YbRb, YbCs, YbSr$^+$, and YbBa$^+$ -- that
may prove fruitful in experimental searches for the electric dipole moment
(EDM) of the electron. These molecules can, in principle, be prepared at
extremely low temperatures by photoassociating ultracold atoms, and therefore
may present an advantage over molecular beam experiments. Here we discuss
properties of these molecules and assess the effective electric fields they
contribute to an electron EDM measurement.
\\ ( http://arxiv.org/abs/0907.4179 , 362kb)
arXiv:0907.3996 (*cross-listing*)
Date: Thu, 23 Jul 2009 07:41:00 GMT (13kb)

Title: Diffusion Approximation of Stochastic Master Equations with Jumps
Authors: Clement Pellegrini and Francesco Petruccione
Categories: math-ph math.MP quant-ph
Comments: 15 pages
   In the presence of quantum measurements with direct photon detection the
evolution of open quantum systems is usually described by stochastic master
equations with jumps. Heuristically, from these equations one can obtain
diffusion models as approximation. A necessary condition for a general
diffusion approximation for jump master equations is presented. This
approximation is rigorously proved by using techniques for Markov process which
are based upon the convergence of Markov generators and martingale problems.
This result is illustrated by rigorously obtaining the diffusion approximation
for homodyne and heterodyne detection.
\\ ( http://arxiv.org/abs/0907.3996 , 13kb)
arXiv:0907.4485 (*cross-listing*)
Date: Sun, 26 Jul 2009 13:56:05 GMT (17kb)

Title: Double Well Potential: Perturbation Theory, Tunneling, WKB (beyond
Authors: Alexander V Turbiner
Categories: math-ph cond-mat.stat-mech hep-th math.MP quant-ph
Comments: 13 pages, invited talk at "Crossing the boundaries: Gauge dynamics at
   strong coupling (Shifmania)", Minneapolis, May 14-17, 2009
   A simple approximate solution for the quantum-mechanical quartic oscillator
$V= m^2 x^2+g x^4$ in the double-well regime $m^2<0$ at arbitrary $g \geq 0$ is
presented. It is based on a combining of perturbation theory near true minima
of the potential, semi-classical approximation at large distances and a
description of tunneling under the barrier. It provides 9-10 significant digits
in energies and gives for wavefunctions the relative deviation in real
$x$-space less than $\lesssim 10^{-3}$.
\\ ( http://arxiv.org/abs/0907.4485 , 17kb)
Date: Fri, 24 Jul 2009 10:09:10 GMT (1482kb)

Title: Experimental Results Related to Discrete Nonlinear Schr\"odinger
Authors: Mason A. Porter
Categories: cond-mat.quant-gas cond-mat.other
Comments: 17 pages, review article
   In this chapter, we discuss experiments that realize the discrete nonlinear
Schr\"odinger (DNLS) equations. The relevance of such descriptions arises from
the competition of three common features: nonlinearity, dispersion, and a
medium to large level of (periodic, quasiperiodic, or random) discreteness in
space. DNLS equations have been especially prevalent in atomic and molecular
physics in the study of Bose-Einstein condensates in optical lattices or
superlattices; and in nonlinear optics in the description of pulse propagation
in waveguide arrays and photorefractive crystals. New experiments in both
nonlinear optics and Bose-Einstein condensation provide new challenges for DNLS
models, and DNLS and related equations have also recently been used to make
important predictions in novel physical settings such as the study of composite
metamaterials and arrays of superconducting devices.
\\ ( http://arxiv.org/abs/0907.4250 , 1482kb)
Date: Fri, 24 Jul 2009 18:10:17 GMT (120kb)

Title: Long Range Free Bosonic Models in Block Decimation Notation:
   Applications and Entanglement
Authors: Jose Reslen and Sougato Bose
Categories: quant-ph
Comments: 4 pages, 3 figures, comments are welcome
   We study the effect of long range particle exchange in bosonic arrangements.
We show that by combining the solution of the Heisenberg equations of motion
with matrix product state representation it is possible to investigate the
dynamics as well as the ground state while including particle exchange beyond
next-neighbours sites. These ideas are then applied to study the emergence of
entanglement as a result of scattering in boson chains. We propose a scheme to
generate highly entangled multi-particle states that exploits collision as a
powerful entangling mechanism.
\\ ( http://arxiv.org/abs/0907.4315 , 120kb)
Date: Fri, 24 Jul 2009 14:42:06 GMT (152kb)

Title: Bogoliubov Theory of acoustic Hawking radiation in Bose-Einstein
Authors: A. Recati, N. Pavloff, I. Carusotto
Categories: cond-mat.quant-gas
Comments: 11 pages, 7 figures
   We apply the microscopic Bogoliubov theory of dilute Bose-Einstein
condensates to analyze quantum and thermal fluctuations in a flowing atomic
condensate in the presence of a sonic horizon. For the simplest case of a
step-like horizon, closed-form analytical expressions are found for the
spectral distribution of the analog Hawking radiation and for the density
correlation function. The peculiar long-distance density correlations that
appear as a consequence of the Hawking emission features turns out to be
reinforced by a finite initial temperature of the condensate. The analytical
results are in good quantitative agreement with first principle numerical
\\ ( http://arxiv.org/abs/0907.4305 , 152kb)
Date: Fri, 24 Jul 2009 15:05:40 GMT (813kb)

Title: Control of unstable macroscopic oscillations in the dynamics of three
   coupled Bose condensates
Authors: P. Buonsante, R. Franzosi, V. Penna
Categories: cond-mat.quant-gas
Comments: 25 pages, 12 figures
Journal-ref: J. Phys. A: Math. Theor. 42 (2009) 285307
DOI: 10.1088/1751-8113/42/28/285307
   We study the dynamical stability of the macroscopic quantum oscillations
characterizing a system of three coupled Bose-Einstein condensates arranged
into an open-chain geometry. The boson interaction, the hopping amplitude and
the central-well relative depth are regarded as adjustable parameters. After
deriving the stability diagrams of the system, we identify three mechanisms to
realize the transition from an unstable to stable behavior and analyze specific
configurations that, by suitably tuning the model parameters, give rise to
macroscopic effects which are expected to be accessible to experimental
observation. Also, we pinpoint a system regime that realizes a
Josephson-junction-like effect. In this regime the system configuration do not
depend on the model interaction parameters, and the population oscillation
amplitude is related to the condensate-phase difference. This fact makes
possible estimating the latter quantity, since the measure of the oscillating
amplitudes is experimentally accessible.
\\ ( http://arxiv.org/abs/0907.4314 , 813kb)
Date: Fri, 24 Jul 2009 23:01:34 GMT (392kb)

Title: Kink-antikink vortex transfer in periodic-plus-random pinning potential:
   Theoretical analysis and numerical experiments
Authors: W.V. Pogosov, H.J. Zhao, V.R. Misko, and F.M. Peeters
Categories: cond-mat.supr-con
Comments: 4 pages, 4 figures
   The influence of random pinning on the vortex dynamics in a periodic square
potential under an external drive is investigated. Using theoretical approach
and numerical experiments, we found several dynamical phases of vortex motion
that are different from the ones for a regular pinning potential. Vortex
transfer is controlled by kinks and antikinks, which either preexist in the
system or appear spontaneously in pairs and then propagate in groups. When
kinks and antikinks collide, they annihilate.
\\ ( http://arxiv.org/abs/0907.4393 , 392kb)
Date: Fri, 24 Jul 2009 07:00:41 GMT (162kb)

Title: Exact ground states and correlation functions of chain and ladder models
   of interacting hardcore bosons or spinless fermions
Authors: Siew-Ann Cheong and Christopher L. Henley
Categories: cond-mat.str-el cond-mat.supr-con
Comments: 20 pages, 18 figures, RevTeX4 class
   By removing one empty site between two occupied sites, we map the ground
states of chains of hardcore bosons and spinless fermions with infinite
nearest-neighbor repulsion to ground states of chains of hardcore bosons and
spinless fermions without nearest-neighbor repulsion respectively, and
ultimately in terms of the one-dimensional Fermi sea. We then introduce the
intervening-particle expansion, where we write correlation functions in such
ground states as a systematic sum over conditional expectations, each of which
can be ultimately mapped to a one-dimensional Fermi-sea expectation. Various
ground-state correlation functions are calculated for the bosonic and fermionic
chains with infinite nearest-neighbor repulsion, as well as for a ladder model
of spinless fermions with infinite nearest-neighbor repulsion and correlated
hopping in three limiting cases. We find that the decay of these correlation
functions are governed by surprising power-law exponents.
\\ ( http://arxiv.org/abs/0907.4228 , 162kb)
Date: Fri, 24 Jul 2009 16:06:20 GMT (140kb)

Title: Emergence of Levy statistics in many-particle quantum systems
Authors: A. V. Ponomarev, S. Denisov, P. Hanggi
Categories: cond-mat.quant-gas cond-mat.stat-mech
Comments: 4 pages, 4 figures
   We consider a system of N strongly interacting (hard-core) bosons at finite
temperatures on a one-dimensional optical lattice with parabolic confinement.
Using two complimentary approaches, canonical and grand-canonical formalisms,
we discovered that the system momentum distribution obeys Levy statistics. The
tunable Levy spline reproduces momentum distributions in the entire
experimentally accessible region, including the first-order diffraction peak.
Our finding allows for calibration of different quantum states by using a
unique scaling exponent and provides an excellent approximation to recent
experimental observations (B. Paredes et al., Nature 429, 277 (2004)).
\\ ( http://arxiv.org/abs/0907.4328 , 140kb)
Date: Fri, 24 Jul 2009 18:54:54 GMT (23kb)

Title: Duality, Quantum Skyrmions and the Stability of an SO(3) Two-Dimensional
   Quantum Spin-Glass
Authors: C.M.S. da Conceicao and E.C.Marino
Categories: cond-mat.dis-nn
Comments: 10 pages, 1 figure
   Quantum topological excitations (skyrmions) are analyzed from the point of
view of their duality to spin excitations in the different phases of a
disordered two-dimensional, short-range interacting, SO(3) quantum magnetic
system of Heisenberg type. The phase diagram displays all the phases, which are
allowed by the duality relation. We study the large distance behavior of the
two-point correlation function of quantum skyrmions in each of these phases
and, out of this, extract information about the energy spectrum and
non-triviality of these excitations. The skyrmion correlators present a
power-law decay in the spin-glass(SG)-phase, indicating that these quantum
topological excitations are gapless but nontrivial in this phase. The SG phase
is dual to the AF phase, in the sense that topological and spin excitations are
respectively gapless in each of them. The Berezinskii-Kosterlitz-Thouless
mechanism guarantees the survival of the SG phase at $T \neq 0$, whereas the AF
phase is washed out to T=0 by the quantum fluctuations. Our results suggest a
new, more symmetric way of characterizing a SG-phase: one for which both the
order and disorder parameters vanish, namely $<\sigma > = 0 $, $<\mu > =0 $,
where $\sigma$ is the spin and $\mu$ is the topological excitation operators.
\\ ( http://arxiv.org/abs/0907.4360 , 23kb)
Date: Fri, 24 Jul 2009 11:15:34 GMT (111kb)

Title: Manipulating mesoscopic multipartite entanglement with atom-light
Authors: Julia Stasi\'nska, Carles Rod\'o, Simone Paganelli, Gerhard Birkl and
   Anna Sanpera
Categories: quant-ph
Comments: 8 pages, 6 figures
   Entanglement between two macroscopic atomic ensembles induced by measurement
on an ancillary light system has proven to be a powerful method for engineering
quantum memories and quantum state transfer. Here we investigate the
feasibility of such methods for generation, manipulation and detection of
genuine multipartite entanglement between mesoscopic atomic ensembles. Our
results extend in a non trivial way the EPR entanglement between two
macroscopic gas samples reported experimentally in [B. Julsgaard, A. Kozhekin,
and E. Polzik, Nature {\bf 413}, 400 (2001)]. We find that under realistic
conditions, a second orthogonal light pulse interacting with the atomic
samples, can modify and even reverse the entangling action of the first one
leaving the samples in a separable state.
\\ ( http://arxiv.org/abs/0907.4261 , 111kb)
Date: Fri, 24 Jul 2009 11:47:22 GMT (4kb)

Title: Energy average formula of photon gas rederived by using the generalized
   Hermann-Feynman theorem
Authors: Hong-yi Fan
Categories: quant-ph
Comments: 2 pages
   By virtue of the generalized Hermann-Feynmam theorem and the method of
characteristics we rederive energy average formula of photon gas, this is
another useful application of the theorem.
\\ ( http://arxiv.org/abs/0907.4267 , 4kb)
Date: Fri, 24 Jul 2009 12:46:26 GMT (2068kb,D)

Title: Observation of St\"uckelberg oscillations in dipole-dipole interactions
Authors: C. S. E. van Ditzhuijzen, Atreju Tauschinsky, H. B. van Linden van den
Categories: quant-ph
   We have observed Stueckelberg oscillations in the dipole-dipole interaction
between Rydberg atoms with an externally applied radio-frequency field. This
proves coherent interaction during at least 0.6 $\mu$s. The oscillating RF
field brings the interaction between cold Rydberg atoms in two separated
volumes in resonance and we observe multi-photon transitions when varying the
amplitude of the RF-field and the static field offset. The angular momentum
states we use show a quadratic Stark shift, which leads to an essentially
different behavior than linearly shifting states. Both cases are studied
theoretically using the Floquet approach and are compared. The amplitude of the
sidebands, related to the interaction strength, is given by the Bessel function
in the linearly shifting case and by the generalized Bessel function in the
quadratically shifting case. Both functions are further studied in the
classical limit. The oscillatory behavior of both functions correspond to
Stueckelberg oscillations, an interference effect described by the
semi-classical Landau-Zener-Stueckelberg model.
\\ ( http://arxiv.org/abs/0907.4275 , 2068kb)
Date: Sat, 25 Jul 2009 08:40:26 GMT (88kb)

Title: Exact solutions of a one-dimensional mixture of spinor bosons and spinor
Authors: Shi-Jian Gu, Junpeng Cao, Shu Chen, and Hai-Qing Lin
Categories: cond-mat.str-el cond-mat.quant-gas
Comments: 25 pages, 10 figres
   The exact solutions of a one-dimensional mixture of spinor bosons and spinor
fermions with $\delta$-function interactions are studied. Some new sets of
Bethe ansatz equations are obtained by using the graded nest quantum inverse
scattering method. Many interesting features appear in the system. For example,
the wave function has the $SU(2|2)$ supersymmetry. It is also found that the
ground state of the system is partial polarized, where the fermions form a spin
singlet state and the bosons are totally polarized. From the solution of Bethe
ansatz equations, it is shown that all the momentum, spin and isospin
rapidities at the ground state are real if the interactions between the
particles are repulsive; while the fermions form two-particle bounded states
and the bosons form one large bound state, which means the bosons condensed at
the zero momentum point, if the interactions are attractive. The charge, spin
and isospin excitations are discussed in detail. The thermodynamic Bethe ansatz
equations are also derived and their solutions at some special cases are
obtained analytically.
\\ ( http://arxiv.org/abs/0907.4410 , 88kb)
Date: Sat, 25 Jul 2009 19:53:26 GMT (50kb)

Title: Spin-Exchange in Hydrogen-Antihydrogen Collisions
Authors: A.Yu. Voronin and P.Froelich
Categories: physics.atom-ph physics.atm-clus
Comments: 16 pages, 4 figures
   We consider the spin-exchange in ultracold collisions of hydrogen ($H$) and
antihydrogen ($\bar{H}$) atoms. The cross sections for transitions between
various hyperfine states are calculated. We show that the process of spin
exchange in $\bar{H}-H$ collisions is basically driven by the strong force
between proton and antiproton, that spin-exchange cross-sections are
proportional to the difference of singlet and triplet strong force S-wave
scattering lengths, while the strong force effects are enhanced about $10^9$
times due to long range atomic forces. We show that any difference in hyperfine
structure of $H$ and $\bar{H}$ (CPT violation) manifests itself in radical
change of spin-exchange cross-sections energy behavior.
\\ ( http://arxiv.org/abs/0907.4444 , 50kb)
Date: Sun, 26 Jul 2009 19:49:30 GMT (273kb)

Title: Observation of an Efimov resonance in an ultracold mixture of atoms and
   weakly bound dimers
Authors: S. Knoop, F. Ferlaino, M. Berninger, M. Mark, H.-C. N\"agerl, R. Grimm
Categories: cond-mat.quant-gas
Comments: Conference Proceeding ICPEAC 2009 Kalamazoo, to appear in Journal of
   Physics: Conference Series
   We discuss our recent observation of an atom-dimer Efimov resonance in an
ultracold mixture of Cs atoms and Cs_2 Feshbach molecules [Nature Phys. 5, 227
(2009)]. We review our experimental procedure and present additional data
involving a non-universal g-wave dimer state, to contrast our previous results
on the universal s-wave dimer. We resolve a seeming discrepancy when
quantitatively comparing our experimental findings with theoretical results
from effective field theory.
\\ ( http://arxiv.org/abs/0907.4510 , 273kb)
Date: Mon, 27 Jul 2009 10:39:59 GMT (947kb)

Title: Single-particle properties and pseudogap effects in the BCS-BEC
   crossover regime of an ultracold Fermi gas above Tc
Authors: Shunji Tsuchiya, Ryota Watanabe, and Yoji Ohashi
Categories: cond-mat.quant-gas
Comments: 23 pages, 11 figures
   We investigate strong-coupling effects on normal state properties of an
ultracold Fermi gas. Within the framework of $T$-matrix approximation in terms
of pairing fluctuations, we calculate the single-particle density of states
(DOS), as well as the spectral weight, over the entire BCS-BEC crossover region
above the superfluid phase transition temperature $T_{\rm c}$. Starting from
the weak-coupling BCS regime, we show that the so-called pseudogap develops in
DOS above $T_{\rm c}$, which becomes remarkable in the crossover region. The
pseudogap structure continuously changes into a fully gapped one in the
strong-coupling BEC regime, where the gap energy is directly related to the
binding energy of tightly bound molecules. We determine the pseudogap
temperature $T^*$ where the dip structure in DOS vanishes. The value of $T^*$
is shown to be very different from another characteristic temperature $T^{**}$
where a BCS-type double peak structure disappears in the spectral weight. While
one finds $T^*>T^{**}$ in the BCS regime, $T^{**}$ becomes higher than $T^*$ in
the crossover region and BEC regime. Including this, we determine the pseudogap
region in the phase diagram of ultracold Fermi gases. Our results would be
useful in the search for the pseudogap region in ultracold $^6$Li and $^{40}$K
Fermi gases.
\\ ( http://arxiv.org/abs/0907.4595 , 947kb)
Date: Mon, 27 Jul 2009 12:07:08 GMT (47kb)

Title: Single-particle density matrix for a time-dependent strongly interacting
   one-dimensional Bose gas
Authors: R. Pezer, T. Gasenzer, H. Buljan
Categories: cond-mat.quant-gas
   We derive a $1/c$-expansion for the single-particle density matrix of a
strongly interacting time-dependent one-dimensional Bose gas, described by the
Lieb-Liniger model ($c$ denotes the strength of the interaction). The formalism
is derived by expanding Gaudin's Fermi-Bose mapping operator up to $1/c$-terms.
We derive an efficient numerical algorithm for calculating the density matrix
for time-dependent states in the strong coupling limit, which evolve from a
family of initial conditions in the absence of an external potential. We have
applied the formalism to study contraction dynamics of a localized wave packet
upon which a parabolic phase is imprinted initially.
\\ ( http://arxiv.org/abs/0907.4608 , 47kb)
Date: Mon, 27 Jul 2009 12:20:40 GMT (33kb)

Title: Bose-Fermi mixtures of self-assembled filaments of fermionic polar
Authors: M. Klawunn, J. Duhme, and L. Santos
Categories: cond-mat.quant-gas
Comments: 4 pages, 4 figures
   Fermionic polar molecules in deep 1D optical lattices may form self-assembled
filaments when the electric dipoles are oriented along the lattice axis. These
composites are bosons or fermions depending on the number of molecules per
chain, leading to a peculiar and complex Bose-Fermi mixture, which we discuss
in detail for the simplest case of a three-well potential. We show that the
interplay between filament binding energy, transverse filament modes, and
trimer Fermi energy leads to a rich variety of possible scenarios ranging from
a degenerate Fermi gas of trimers to a binary mixture of two different types of
bosonic dimers. We study the intriguing zero temperature and finite temperature
physics of these composites for the particular case of an ideal filament gas
loaded in 1D sites, and discuss possible methods to probe these chain mixtures.
\\ ( http://arxiv.org/abs/0907.4612 , 33kb)
Date: Mon, 27 Jul 2009 19:26:57 GMT (16kb)

Title: Phase Diagrams of Spinor Bose Gases
Authors: Kun Yang
Categories: cond-mat.quant-gas
Comments: 4 pages
   Using effective field theories dictated by the symmetry of the system, as
well as microscopic considerations, we map out the magnetic
coupling-temperature phase diagrams of spin-1 Bose gases in both two- and
three-dimensions. We also determine the nature of all phase boundaries, and
critical properties in the case of 2nd order phase transitions at both zero and
finite temperatures.
\\ ( http://arxiv.org/abs/0907.4739 , 16kb)
Date: Mon, 27 Jul 2009 09:31:08 GMT (107kb)

Title: Ground state properties of a one-dimensional strongly-interacting
   Bose-Fermi mixture in a double-well potential
Authors: K. Lelas, D. Juki\'c, H. Buljan
Categories: cond-mat.quant-gas
Comments: 10 figures
   We calculate the reduced single-particle density matrix (RSPDM), momentum
distributions, natural orbitals and their occupancies, for a strongly
interacting one-dimensional Bose-Fermi mixture in a double-well potential with
a large central barrier. For mesoscopic systems, we find that the ground state
properties qualitatively differ for mixtures with even number of particles
(both odd-odd and even-even mixtures) in comparison to mixtures with odd
particle numbers (odd-even and even-odd mixtures). For even mixtures the
momentum distribution is smooth, whereas the momentum distribution of odd
mixtures possesses distinct modulations; the differences are observed also in
the off-diagonal correlations of the RSPDM, and in the occupancies of natural
orbitals. The calculation is based on a derived formula which enables efficient
calculation of the RSPDM for mesoscopic mixtures in various potentials.
\\ ( http://arxiv.org/abs/0907.4580 , 107kb)
Date: Mon, 27 Jul 2009 14:41:04 GMT (95kb)

Title: Exact ground state Monte Carlo method for Bosons without importance
Authors: M. Rossi, M. Nava, L. Reatto and D.E. Galli
Categories: cond-mat.other
Comments: 10 pages, 9 figures
   All "exact" Quantum Monte Carlo methods for the ground state of Boson systems
developed so far make use of importance sampling based either on a guiding
function or on an initial variational wave function. Here we investigate the
need of importance sampling in the case of Path Integral Ground State (PIGS)
Monte Carlo. PIGS is based on a discrete imaginary time evolution of an initial
wave function with a non zero overlap with the ground state, that gives rise to
a discrete path which is sampled via a Metropolis like algorithm. In principle
the exact ground state is reached in the limit of an infinite imaginary time
evolution, but actual computations are based on finite time evolutions and the
question is whether such computations give unbiased exact results. We have
studied bulk liquid and solid 4He with PIGS by considering as initial wave
function a constant, i.e. the ground state of an ideal Bose gas. This implies
that the evolution toward the ground state is driven only by the imaginary time
propagator, i.e. there is no importance sampling. For both the phases we obtain
results converging to those obtained by considering the best available
variational wave function (the Shadow wave function) as initial wave function.
Moreover we obtain the same results even by considering wave functions with the
wrong correlations, for instance a wave function of a strongly localized
Einstein crystal for the liquid phase. This convergence is true not only for
diagonal properties such as the energy, the radial distribution function and
the static structure factor, but also for off--diagonal ones, such as the
one--body density matrix. From this analysis we conclude that zero temperature
PIGS calculations can be as unbiased as those of finite temperature Path
Integral Monte Carlo.
\\ ( http://arxiv.org/abs/0907.4430 , 95kb)
Date: Mon, 27 Jul 2009 21:44:34 GMT (316kb)

Title: Matter-wave bistability in coupled atom-molecule quantum gases
Authors: Lei Jiang, Han Pu, Andrew Robertson, Hong Y. Ling
Categories: cond-mat.quant-gas
Comments: 6 pages, 5 figures
   We study the matter-wave bistability in coupled atom-molecule quantum gases,
in which heteronuclear molecules are created via an interspecies Feshbach
resonance involving either two-species Bose or two-species Fermi atoms at zero
temperature. We show that the resonant two-channel Bose model is equivalent to
the nondegenerate parametric down-conversion in quantum optics, while the
corresponding Fermi model can be mapped to a quantum optics model that
describes a single-mode laser field interacting with an ensemble of
inhomogeneously broadened two-level atoms. Using these analogy and the fact
that both models are subject to the Kerr nonlinearity due to the two-body
s-wave collisions, we show that under proper conditions, the population in the
molecular state in both models can be made to change with the Feshbach detuning
in a bistable fashion.
\\ ( http://arxiv.org/abs/0907.4779 , 316kb).
Date: Mon, 27 Jul 2009 17:37:36 GMT (69kb)

Title: Magnetic field imaging with atomic Rb vapor
Authors: Eugeniy E. Mikhailov (1), I. Novikova (1), M. D. Havey (2), F. A.
   Narducci (3) ((1) Department of Physics, The College of William & Mary, (2)
   Department of Physics, Old Dominion University, (3) EO Sensors Division,
   Naval Air Systems Command)
Categories: quant-ph
Comments: 4 pages, 3 figures
   We demonstrate the possibility of dynamic imaging of magnetic fields using
electromagnetically induced transparency in an atomic gas. As an experimental
demonstration we employ an atomic Rb gas confined in a glass cell to image the
transverse magnetic field created by a long straight wire. In this arrangement,
which clearly reveals the essential effect, the field of view is about 2 x 2
mm^2 and the field detection uncertainty is 0.14 mG per 10 um x 10 um image
\\ ( http://arxiv.org/abs/0907.4683 , 69kb)
Date: Mon, 27 Jul 2009 19:05:24 GMT (21kb)

Title: Faddeev equations in one-dimensional problems with resonant interactions
Authors: Vladimir A. Yurovsky
Categories: physics.atom-ph
   A problem of three one-dimensional bosons with resonant multichannel
interactions is considered. The problem is reduced to a single-channel
Faddeev-Lovelace equation by elimination of the closed and output channels. The
equation is regularized using algebraic properties of their singularities.
\\ ( http://arxiv.org/abs/0907.4734 , 21kb)
Date: Mon, 27 Jul 2009 02:26:33 GMT (16kb)

Title: Translation-symmetry protected topological orders on lattice
Authors: Su-Peng Kou and Xiao-Gang Wen
Categories: cond-mat.str-el
   In this paper we systematically study a simple class of translation-symmetry
protected topological orders in quantum spin systems using slave-particle
approach. The spin systems on square lattice are translation invariant, but may
break any other symmetries. We consider topologically ordered ground states
that do not spontaneously break any symmetry. Those states can be described by
Z2A or Z2B projective symmetry group. We find that the Z2A translation
symmetric topological orders can still be divided into 16 sub-classes
corresponding to 16 new translation-symmetry protected topological orders. We
introduced four $Z_2$ topological indices $\zeta_{\v{k}}=0,1$ at $\v
{k}=(0,0)$, $(0,\pi)$, $(\pi, 0)$, $(\pi ,\pi)$ to characterize those 16 new
topological orders. We calculated the topological degeneracies and crystal
momenta for those 16 topological phases on even-by-even, even-by-odd,
odd-by-even, and odd-by-odd lattices, which allows us to physically measure
such topological orders. We predict the appearance of gapless fermionic
excitations at the quantum phase transitions between those symmetry protected
topological orders. Our result can be generalized to any dimensions. We find
256 translation-symmetry protected Z2A topological orders for a system on 3D
\\ ( http://arxiv.org/abs/0907.4537 , 16kb)
Date: Mon, 27 Jul 2009 12:56:28 GMT (717kb,D)

Title: Gap polariton solitons
Authors: A. V. Gorbach, B. A. Malomed, D. V. Skryabin
Categories: physics.optics nlin.PS
Comments: 11 pages, 7 figures, published in PLA
Journal-ref: Physics Letters A 373, 3024-3027 (2009)
   We report the existence, and study mobility and interactions of gap polariton
solitons in a microcavity with a periodic potential, where the light field is
strongly coupled to excitons. Gap solitons are formed due to the interplay
between the repulsive exciton-exciton interaction and cavity dispersion. The
analysis is carried out in an analytical form, using the coupled-mode (CM)
approximation, and also by means of numerical methods.
\\ ( http://arxiv.org/abs/0907.4440 , 717kb)
Date: Mon, 27 Jul 2009 05:48:13 GMT (25kb)

Title: Creation of pure multi-mode entangled states in a ring cavity
Authors: Gao-xiang Li and Zbigniew Ficek
Categories: quant-ph
Comments: 8 pages, 1 figure, "Quo vadis Quantum Optics"- special issue of
   Optics Communications memory of Krzysztof Wodkiewicz
   Practical schemes for creation of multi-mode squeezed (entangled) states of
atomic ensembles located inside a high-Q ring cavity are discussed. It is
assumed that the cavity is composed of two degenerate mutually
counter-propagating modes that can simultaneously couple to the atomic
ensembles with the same coupling strengths. The ensembles are composed of
ultra-cold atoms which are modeled as four-level systems driven by two laser
fields, both co-propagating with one of the cavity directions. We illustrate a
procedure that constructs multi-mode squeezed states from the vacuum by a
unitary transformation associated with the collective dynamics of the atomic
ensembles subjected to driving lasers of a suitably adjusted amplitudes and
phases. The laser prepare the collective modes in a desired squeezed state that
then decay to a steady-state with the rate determined by the cavity damping
\\ ( http://arxiv.org/abs/0907.4546 , 25kb)
Date: Mon, 27 Jul 2009 10:24:40 GMT (238kb,D)

Title: $N$-Slit Interference: Fractals in Near-Field Region, Bohmian
Authors: Valeriy I. Sbitnev
Categories: quant-ph
Comments: 8 pages, 7 figures
   Scattering cold particles on an $N$-slit grating is shown to reproduce an
interference pattern, that manifests itself in the near-field region as the
fractal Talbot carpet. In the far-field region the pattern is transformed to an
ordinary diffraction, where principal beams are partitioned from each other by
($N-2$) weak ones. A probability density plot of the wave function, to be
represented by a gaussian wavepacket, is calculated both in the near-field
region and in the far-field one. Bohmian (geodesic) trajectories, to be
calculated by a guidance equation, are superimposed on the probability density
plot well enough. It means, that a particle, moving from a source to a
detector, passes across the grating along a single bohmian trajectory
through-passing one and only one slit.
   Keywords: Gaussian wavepacket, near-field interference, far-field
diffraction, Talbot carpet, fractal, bohmian trajectory, guidance equation
\\ ( http://arxiv.org/abs/0907.4638 , 238kb)
Date: Mon, 27 Jul 2009 14:59:30 GMT (31kb,D)

Title: Approximating strongly correlated spin and fermion wavefunctions with
   correlator product states
Authors: Hitesh J. Changlani, Jesse M. Kinder, Cyrus J. Umrigar, and Garnet
   Kin-Lic Chan
Categories: cond-mat.str-el
Comments: 5 pages, 1 figure, 2 tables, submitted to Phys. Rev. Lett
   We explore correlator product states for the approximation of correlated
wavefunctions in arbitrary dimensions. We show that they encompass many
interesting states including Laughlin's quantum Hall wavefunction, Huse and
Elser's frustrated spin states, and Kitaev's toric code. We further establish
their relation to common families of variational wavefunctions, such as matrix
and tensor product states and resonating valence bond states. Calculations on
the Heisenberg and spinless Hubbard models show that correlator product states
capture both two-dimensional correlations (independent of system width) as well
as non-trivial fermionic correlations (without sign problems). In
one-dimensional simulations, correlator product states appear competitive with
matrix product states with a comparable number of variational parameters,
suggesting they may eventually provide a route to practically generalise the
density matrix renormalisation group to higher dimensions.
\\ ( http://arxiv.org/abs/0907.4646 , 31kb)
Date: Tue, 28 Jul 2009 15:25:01 GMT (54kb)

Title: Bose-Einstein condensation of polaritons in graphene in a high magnetic
Authors: Oleg L. Berman, Roman Ya. Kezerashvili, and Yurii E. Lozovik
Categories: cond-mat.mes-hall cond-mat.str-el
Comments: 7 pages, 1 figure
   The Bose-Einstein condensation (BEC) of magnetoexcitonic polaritons in a
graphene layer embedded in a optical microcavity in a high magnetic field $B$
is predicted. The essential property of this system (in contrast, e.g., to a
quantum well embedded in a cavity) is stronger influence of magnetic field and
weaker influence of disorder. A two-dimensional (2D) magnetoexcitonic
polaritons gas is considered in a planar harmonic electric field potential
applied to excitons or a parabolic shape of the optical cavity causing the
trapping of microcavity photons. It is shown that the effective polariton mass
$M_{\rm eff}$ increases with magnetic field as $B^{1/2}$. The BEC critical
temperature $T_{c}^{(0)}$ decreases as $B^{-1/4}$ and increases with the spring
constant of the parabolic trap. The Rabi splitting related to the creation of a
magnetoexciton in a high magnetic field in graphene is obtained.
\\ ( http://arxiv.org/abs/0907.4934 , 54kb)
Date: Tue, 28 Jul 2009 19:41:36 GMT (66kb)

Title: The Casimir Effect from a Condensed Matter Perspective
Authors: L. Palova, P. Chandra and P. Coleman
Categories: cond-mat.other cond-mat.mes-hall
Comments: Accepted for Publication in American Journal of Physics
   The Casimir effect, a key observable realization of vacuum fluctuations, is
usually taught in graduate courses on quantum field theory. The growing
importance of Casimir forces in microelectromechanical systems motivates this
subject as a topic for graduate many-body physics courses. To this end, we
revisit the Casimir effect using methods common in condensed matter physics. We
recover previously derived results and explore the implications of the
analogies implicit in this treatment.
\\ ( http://arxiv.org/abs/0907.4976 , 66kb)
Date: Wed, 29 Jul 2009 08:07:29 GMT (448kb)

Title: Derivation of non-Markoffian transport equations for trapped cold atoms
   in nonequilibrium thermal field theory
Authors: Y.Nakamura, T.Sunaga, M.Mine, M.Okumura, Y.Yamanaka
Categories: cond-mat.quant-gas cond-mat.other
Comments: 12 pages, 2 figures
   The non-Markoffian transport equations for the systems of cold Bose atoms
confined by a external potential both without and with a Bose-Einstein
condensate are derived in the framework of nonequilibrium thermal filed theory
(Thermo Field Dynamics). Our key elements are an explicit particle
representation and a self-consistent renormalization condition which are
essential in thermal field theory. The non-Markoffian transport equation for
the non-condensed system, derived at the two-loop level, is reduced in the
Markoffian limit to the ordinary quantum Boltzmann equation derived in the
other methods. For the condensed system, we derive a new transport equation
with an additional collision term which becomes important in the Landau
\\ ( http://arxiv.org/abs/0907.5061 , 448kb)
arXiv:0907.5129 (*cross-listing*)
Date: Wed, 29 Jul 2009 13:53:27 GMT (21kb)

Title: Quantum measures for density correlations in optical lattices
Authors: F. Benatti, R. Floreanini and G.G. Guerreschi
Categories: quant-ph cond-mat.quant-gas
Comments: LaTeX, 14 pages
   The density-density correlation profiles obtained superimposing absorption
images from atomic clouds freely expanding after the release of the confining
optical lattice can be theoretically described in terms of a generalized
quantum measure based on coherent-like states. We show that the corresponding
density patterns differ in a testable way from those computed using standard
many-body mean values, usually adopted in fitting experimental data.
\\ ( http://arxiv.org/abs/0907.5129 , 21kb)
Date: Wed, 29 Jul 2009 20:18:17 GMT (2340kb)

Title: Photonic quantum transport in a nonlinear optical fiber
Authors: Mohammad Hafezi, Darrick E. Chang, Vladimir Gritsev, Eugene Demler,
   Mikhail D. Lukin
Categories: quant-ph
Comments: 5 pages, 4 figures
   We theoretically study the transmission of few-photon quantum fields through
a strongly nonlinear optical medium. We develop a general approach to
investigate non-equilibrium quantum transport of bosonic fields through a
finite-size nonlinear medium and apply it to a recently demonstrated
experimental system where cold atoms are loaded in a hollow-core optical fiber.
We show that when the interaction between photons is effectively repulsive, the
system acts as a single-photon switch. In the case of attractive interaction,
the system can exhibit either anti-bunching or bunching, associated with the
resonant excitation of bound states of photons by the input field. These
effects can be observed by probing statistics of photons transmitted through
the nonlinear fiber.
\\ ( http://arxiv.org/abs/0907.5206 , 2340kb)
Date: Thu, 30 Jul 2009 19:48:06 GMT (489kb)

Title: Simulations of the Dipole-Dipole Interaction between Two Spatially
   Separated Groups of Rydberg Atoms
Authors: T. J. Carroll (1), C. Daniel (1), L. Hoover (1), T. Sidie (1), and M.
   W. Noel (2) ((1) Ursinus College, (2) Bryn Mawr College)
Categories: physics.atom-ph
Comments: 9 pages, 11 figures
   The dipole-dipole interaction among ultra-cold Rydberg atoms is simulated. We
examine a general interaction scheme in which two atoms excited to the x and x'
states are converted to y and y' states via a Forster resonance. The atoms are
arranged in two spatially separated groups, each consisting of only one species
of atom. We record the fraction of atoms excited to the y' state as the
distance between the two groups is varied. With zero detuning a many-body
effect that relies on always resonant interactions causes the interaction to
have a finite range. When the detuning is greater than zero, another many-body
effect causes a peak in the interaction when the two groups of atoms are some
distance away from each other. To obtain these results it is necessary to
include multiple atoms and solve the full many-body wave function. These
simulation results are supported by recent experimental evidence. These
many-body effects, combined with appropriate spatial arrangement of the atoms,
could be useful in controlling the energy exchange among the atoms.
\\ ( http://arxiv.org/abs/0907.5405 , 489kb)
Date: Thu, 30 Jul 2009 13:34:11 GMT (39kb)

Title: Spectrum of bound fermion states on vortices in $^3$He-B
Authors: M.A. Silaev
Categories: cond-mat.other
Comments: 6 pages, 1 figure
   We study subgap spectra of fermions localized within vortex cores in
$^3$He-B. We develop an analytical treatment of the low-energy states and
consider the characteristic properties of fermion spectra for different types
of vortices. Due to the removed spin degeneracy the spectra of all singly
quantized vortices consist of two different anomalous branches crossing the
Fermi level. For singular $o$ and $u$ vortices the anomalous branches are
similar to the standard Caroli-de Gennes -Matricon ones and intersect the Fermi
level at zero angular momentum yet with different slopes corresponding to
different spin states. On the contrary the spectral branches of nonsingular
vortices intersect the Fermi level at finite angular momenta which leads to the
appearance of a large number of zero modes, i.e. energy states at the Fermi
level. Considering the $v$, $w$ and $uvw$ vortices with superfluid cores we
show that the number of zero modes is proportional to the size of the vortex
\\ ( http://arxiv.org/abs/0907.5341 , 39kb)
Date: Thu, 30 Jul 2009 13:56:48 GMT (118kb)

Title: Thomas-Fermi Approximation for a Condensate with Higher-order
Authors: M. Th{\o}gersen, N. T. Zinner, A. S. Jensen
Categories: cond-mat.quant-gas cond-mat.stat-mech
Comments: 7+ pages, RevTex4 format, 5 figures
   We consider the ground-state of a harmonically trapped Bose-Einstein
condensate within the Gross-Pitaevskii theory including the effective range
corrections for a two-body zero-range potential. The resulting non-linear
Schr{\"o}dinger equation is solved analytically in the Thomas-Fermi
approximation neglecting the kinetic energy term. We present results for the
chemical potential and the condensate profiles, discuss boundary conditions,
and compare to the usual Thomas-Fermi approach. Our findings indicate that
kinetic energy terms are intrinsically important when including higher-order
corrections, both for theoretical consistence and in concrete physical systems.
\\ ( http://arxiv.org/abs/0907.5349 , 118kb)
Date: Thu, 30 Jul 2009 18:28:29 GMT (17kb)

Title: Fermion zero modes at the boundary of superfluid 3He-B
Authors: G.E. Volovik
Categories: cond-mat.other cond-mat.str-el
Comments: 3 pages, no Figures, JETP Letters style
   Superfluid 3He-B belongs to the important special class of time-reversal
invariant topological superfluids. It has Majorana fermions as edge states on
the surface of bulk 3He-B. On the rough wall these fermion zero modes have
finite density of states at E=0.
\\ ( http://arxiv.org/abs/0907.5389 , 17kb)
Date: Thu, 30 Jul 2009 19:47:15 GMT (82kb,D)

Title: Natural mode entanglement as a resource for quantum communication
Authors: Libby Heaney and Vlatko Vedral
Categories: quant-ph
Comments: 4 pages, 1 figure, comments welcome
   Natural particle-number entanglement resides between spatial modes in
coherent ultra-cold atomic gases. However, operations on the modes are
restricted by a superselection rule that forbids coherent superpositions of
different particle numbers. This seemingly prevents mode entanglement being
used as a resource for quantum communication. In this paper, we demonstrate
that mode entanglement of a single massive particle can be used for dense
coding and quantum teleportation despite the superselection rule. In
particular, we provide schemes where the dense coding linear photonic channel
capacity is reached without a shared reservoir and where the full quantum
channel capacity is achieved if both parties share a coherent particle
\\ ( http://arxiv.org/abs/0907.5404 , 82kb)
Date: Wed, 29 Jul 2009 15:37:58 GMT (1719kb)

Title: Interference of Cooper Pairs Emitted from Independent Superconductors
Authors: Mauro Iazzi, Kazuya Yuasa
Categories: cond-mat.supr-con
Comments: 4 pages, 3 figures
   We discuss the interference in the two-particle distribution of the electrons
emitted from two independent superconducting tips. The two-particle correlation
exhibits interesting oscillating patterns due to Andreev processes, from which
one can measure the relative phase of the two superconductors. The phases are
fixed as a result of the spontaneous symmetry breaking, and the interference
patterns appear with a definite fringe spacing but with different offsets for
different realizations of the superconducting states. It is clarified that this
is nothing but the first-order interference of Cooper pairs emitted from
different but coherent sources and is the equivalent of the interference of two
independent Bose-Einstein condensates.
\\ ( http://arxiv.org/abs/0907.5161 , 1719kb)

The replacements:

replaced with revised version Thu, 23 Jul 2009 01:43:01 GMT (125kb,D)

Title: Measurement of inelastic losses in a sample of ultracold Rb-85
Authors: P. A. Altin, N. P. Robins, R. Poldy, J. E. Debs, D. D\"oring, C. Figl
   and J. D. Close
Categories: physics.atom-ph
Comments: 4 pages, 3 figures, content changed
\\ ( http://arxiv.org/abs/0902.2229 , 125kb)
replaced with revised version Fri, 24 Jul 2009 19:04:21 GMT (1329kb)

Title: Supersolidity of Cold Atomic Bose-Fermi mixtures in optical lattices
Authors: Peter P. Orth, Doron L. Bergman, and Karyn Le Hur
Categories: cond-mat.quant-gas
Comments: Moved technical details to appendices. Enlarged list of references
\\ ( http://arxiv.org/abs/0905.1125 , 1329kb)
replaced with revised version Thu, 23 Jul 2009 18:52:05 GMT (124kb,D)

Title: Hyperfine-interaction- and magnetic-field-induced
   Bose-Einstein-statistics suppressed two-photon transitions
Authors: M. G. Kozlov, D. English, D. Budker
Categories: physics.atom-ph
\\ ( http://arxiv.org/abs/0907.3727 , 124kb)
replaced with revised version Fri, 24 Jul 2009 17:47:33 GMT (113kb)

Title: Polaron formation as a genuine nonequilibrium phenomenon
Authors: S. Ajisaka, S. Tasaki, and I. Terasaki
Categories: cond-mat.stat-mech
Comments: 4 pages, 6 figures
\\ ( http://arxiv.org/abs/0907.0218 , 113kb)
replaced with revised version Fri, 24 Jul 2009 11:13:24 GMT (517kb)

Title: Observation of a Non-local Optical Vortex
Authors: R. M. Gomes, A. Salles, F. Toscano, P. H. Souto Ribeiro and S. P.
Categories: quant-ph
Comments: 4 pages, 4 figures
Journal-ref: Phys. Rev. Lett. 103, 033602 (2009)
\\ ( http://arxiv.org/abs/0902.1659 , 517kb)
replaced with revised version Sun, 26 Jul 2009 09:29:58 GMT (30kb)

Title: Spin chain description of rotating bosons at $\nu=1$
Authors: Emma Wikberg, Emil J. Bergholtz and Anders Karlhede
Categories: cond-mat.mes-hall cond-mat.str-el
Comments: Published. 19 pages, 4 figures
Journal-ref: J. Stat. Mech. (2009) P07038
DOI: 10.1088/1742-5468/2009/07/P07038
\\ ( http://arxiv.org/abs/0903.4093 , 30kb)
replaced with revised version Sun, 26 Jul 2009 19:00:41 GMT (111kb)

Title: Inhomogeneous spectral moment sum rules for the retarded Green function
   and self-energy of strongly correlated electrons or ultracold fermionic atoms
   in optical lattices
Authors: J. K. Freericks (Georgetown University) and V. Turkowski (University
   of Central Florida)
Categories: cond-mat.str-el cond-mat.quant-gas
Comments: (28 pages, 6 figures, ReVTeX) Paper updated to correct equations 11,
   24, and 28
\\ ( http://arxiv.org/abs/0907.1284 , 111kb)
replaced with revised version Sun, 26 Jul 2009 01:58:27 GMT (1449kb,D)

Title: Magnetic field sensing beyond the standard quantum limit using 10-spin
   NOON states
Authors: Jonathan A. Jones, Steven D. Karlen, Joe Fitzsimons, Arzhang Ardavan,
   Simon C. Benjamin, G. A. D. Briggs and John J. L. Morton
Categories: quant-ph
Comments: 5 pages, 3 figures
Journal-ref: Science 324, 1166-1168 (2009)
DOI: 10.1126/science.1170730
\\ ( http://arxiv.org/abs/0811.4350 , 1449kb)
replaced with revised version Mon, 27 Jul 2009 18:51:13 GMT (2399kb)

Title: Dynamics of formation and decay of coherence in a polariton condensate
Authors: E. del Valle, D. Sanvitto, A. Amo, F.P. Laussy, A. Andre, C. Tejedor
   and L. Vina
Categories: cond-mat.mes-hall
\\ ( http://arxiv.org/abs/0903.1954 , 2399kb)
replaced with revised version Mon, 27 Jul 2009 16:51:11 GMT (443kb)

Title: Quantum Control of Interacting Bosons in Periodic Optical Lattice
Authors: Analabha Roy, Linda E. Reichl
Categories: physics.atom-ph
Comments: Sent to Physical Review A Corrected spelling mistake in name
\\ ( http://arxiv.org/abs/0907.3813 , 443kb)
arXiv:0904.1975 (*cross-listing*)
replaced with revised version Mon, 27 Jul 2009 17:32:17 GMT (619kb,D)

Title: Lectures on Holographic Superfluidity and Superconductivity
Authors: Christopher P. Herzog
Categories: hep-th cond-mat.str-el
Comments: 39 pages, 9 figures, lectures given at the Trieste Spring School on
   Superstring Theory and Related Topics; v2 small corrections, to appear in J.
   Phys. A
\\ ( http://arxiv.org/abs/0904.1975 , 619kb)
arXiv:0904.2614 (*cross-listing*)
replaced with revised version Mon, 27 Jul 2009 10:28:10 GMT (190kb)

Title: Control of spin correlations by periodic driving
Authors: K. Kudo, T. Boness and T.S. Monteiro
Categories: quant-ph cond-mat.other
Comments: 5 pages, 3 figures
\\ ( http://arxiv.org/abs/0904.2614 , 190kb)
replaced with revised version Mon, 27 Jul 2009 12:06:08 GMT (140kb)

Title: Emergence of Levy statistics in many-particle quantum systems
Authors: A. V. Ponomarev, S. Denisov, P. Hanggi
Categories: cond-mat.quant-gas cond-mat.stat-mech
Comments: 4 pages, 4 figures
\\ ( http://arxiv.org/abs/0907.4328 , 140kb)
replaced with revised version Mon, 27 Jul 2009 14:38:40 GMT (265kb)

Title: Quantum linear Boltzmann equation
Authors: Bassano Vacchini, Klaus Hornberger
Categories: quant-ph math-ph math.MP
Comments: 63 pages, 6 figures; v3:corresponds to published version
Journal-ref: Physics Reports 478 (2009) 71-120
DOI: 10.1016/j.physrep.2009.06.001
\\ ( http://arxiv.org/abs/0904.3911 , 265kb)
arXiv:0907.3689 (*cross-listing*)
replaced with revised version Tue, 28 Jul 2009 13:44:09 GMT (174kb,D)

Title: Contraction of fermionic operator circuits and the simulation of
   strongly correlated fermions
Authors: Thomas Barthel and Carlos Pineda and Jens Eisert
Categories: cond-mat.str-el quant-ph
Comments: 12 pages, 9 pdf figures; minor changes, one figure added, references
\\ ( http://arxiv.org/abs/0907.3689 , 174kb)
replaced with revised version Tue, 28 Jul 2009 14:55:22 GMT (1298kb)

Title: Magnetism, coherent many-particle dynamics, and relaxation with
   ultracold bosons in optical superlattices
Authors: Thomas Barthel, Christian Kasztelan, Ian P. McCulloch, Ulrich
Categories: cond-mat.stat-mech
Comments: 20 pages, 24 figures; minor changes, published version
Journal-ref: Phys. Rev. A 79, 053627 (2009)
DOI: 10.1103/PhysRevA.79.053627
\\ ( http://arxiv.org/abs/0809.5141 , 1298kb)
replaced with revised version Tue, 28 Jul 2009 15:27:06 GMT (226kb)

Title: Spectral functions in one-dimensional quantum systems at T>0
Authors: Thomas Barthel, Ulrich Schollw\"ock and Steven R. White
Categories: cond-mat.str-el
Comments: 6 pages, 8 figures; added comparison to quantum Monte Carlo, extended
   discussion of the method, 4 figures added; published version
Journal-ref: Phys. Rev. B 79, 245101 (2009)
DOI: 10.1103/PhysRevB.79.245101
\\ ( http://arxiv.org/abs/0901.2342 , 226kb)
replaced with revised version Tue, 28 Jul 2009 07:34:21 GMT (42kb)

Title: Josephson oscillations between exciton condensates in electrostatic
Authors: Massimo Rontani, L. J. Sham
Categories: cond-mat.mes-hall
Comments: RevTeX 4.0. 6 pages, 3 figures. We added new material (Fig. 3) and
   references. To appear in Physical Review B
\\ ( http://arxiv.org/abs/0902.3967 , 42kb)
replaced with revised version Tue, 28 Jul 2009 18:33:02 GMT (108kb)

Title: Mesoscopic quantum switching of a Bose-Einstein condensate in an optical
   lattice governed by the parity of the number of atoms
Authors: V. S. Shchesnovich
Categories: cond-mat.quant-gas
Comments: Added the discussion of stability of the parity effect under small
   perturbations and the inhomogeneity of the lattice; 4 pages, 3 figures in
\\ ( http://arxiv.org/abs/0905.1708 , 108kb)
replaced with revised version Tue, 28 Jul 2009 08:22:52 GMT (1482kb)

Title: Experimental Results Related to Discrete Nonlinear Schr\"odinger
Authors: Mason A. Porter
Categories: cond-mat.quant-gas cond-mat.other nlin.PS physics.atom-ph
Comments: 17 pages, review article; (document is same as before, but I forgot
   to include the reference to the published version in Journal-ref); in P. G.
   Kevrekidis, Discrete Nonlinear Schr\"odinger Equation: Mathematical Analysis,
   Numerical Computations, and Physics Perspectives, 175-189, Springer Tracts in
   Modern Physics (Springer-Verlag)
\\ ( http://arxiv.org/abs/0907.4250 , 1482kb)
replaced with revised version Tue, 28 Jul 2009 21:24:07 GMT (145kb)

Title: Effects of a dilute gas of fermions on the superfluid-insulator phase
   diagram of the Bose-Hubbard model
Authors: Sumanta Tewari, Roman M. Lutchyn, S. Das Sarma
Categories: cond-mat.str-el quant-ph
Comments: 16 pages, 5 eps figures; final version to appear in PRB
\\ ( http://arxiv.org/abs/0902.0172 , 145kb)
replaced with revised version Tue, 28 Jul 2009 08:45:27 GMT (35kb)

Title: Multiple condensed phases in attractively interacting Bose systems
Authors: M. M\"annel, K. Morawetz, P. Lipavsk\'y
Categories: cond-mat.stat-mech nucl-th
\\ ( http://arxiv.org/abs/0902.4119 , 35kb)
arXiv:0901.1106 (*cross-listing*)
replaced with revised version Wed, 29 Jul 2009 21:05:54 GMT (9kb)

Title: Bose-Einstein Condensation of Dark Matter Axions
Authors: P. Sikivie and Q. Yang
Categories: hep-ph astro-ph.CO cond-mat.stat-mech
Comments: 4 pages. The paper has been substantially rewritten. The conclusions
   are unchanged
Report-no: UFIFT-HEP-09-1
\\ ( http://arxiv.org/abs/0901.1106 , 9kb)
replaced with revised version Thu, 30 Jul 2009 00:47:20 GMT (113kb)

Title: The Non-universal behaviour of Cold Fermi Condensates with Narrow
   Feshbach Resonances
Authors: Chi-Yong Lin, Da-Shin Lee, and Ray J. Rivers
Categories: cond-mat.supr-con
Comments: 7 pages, there is no differences in results between this (v2) and the
   older version (v1), but v2 makes the nature of the non-canonical behavior of
   the EOS clearer
\\ ( http://arxiv.org/abs/0810.1796 , 113kb)

Till next time,

Dr M. J. Davis,                      Associate Professor in Physics
School of Mathematics and Physics,   ph  : +61 7 334 69824
The University of Queensland,        fax : +61 7 336 51242
Brisbane, QLD 4072,                  mdavis_at_physics.uq.edu.au
Australia.                           www.physics.uq.edu.au/people/mdavis/
Matt's arXiv selection: weekly summary of cold-atom papers from arXiv.org
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