Matt's arXiv selection: week ending 20 June 2008

From: Matthew Davis <>
Date: Sun, 29 Jun 2008 21:10:46 +1000

The following message was sent to the matts_arxiv list by "Matthew Davis" <>


This week there were 28 new preprints and 22 replacements:

Date: Fri, 13 Jun 2008 13:14:58 GMT (571kb)

Title: Disordered vortex arrays in a two-dimensional condensate
Authors: E. J. M. Madarassy and C. F. Barenghi
Categories: cond-mat.dis-nn cond-mat.stat-mech
Comments: 14 pages, 18 figures, submitted to Geophysical and Astrophysical
   Fluid Dynamics
   We suggest a method to create turbulence in a Bose-Einstein condensate. The
method consists in, firstly, creating an ordered vortex array, and, secondly,
imprinting a phase difference in different regions of the condensate. By
solving numerically the two-dimensional Gross-Pitaevskii equation we show that
the motion of the resulting positive and negative vortices is disordered.
\\ ( , 571kb)
Date: Fri, 13 Jun 2008 16:15:09 GMT (205kb)

Title: Exact Relations for a Strongly-interacting Fermi Gas near a Feshbach
Authors: Eric Braaten, Daekyoung Kang, Lucas Platter
Categories: cond-mat.other
Comments: 25 pages, 8 figures
   A set of universal relations between various properties of any few-body or
many-body system consisting of fermions with two spin states and a large but
finite scattering length have been derived by Shina Tan. We derive
generalizations of the Tan relations for a two-channel model for fermions near
a Feshbach resonance that includes a molecular state whose detuning energy
controls the scattering length. We use quantum field theory methods, including
renormalization and the operator product expansion, to derive these relations.
They reduce to the Tan relations as the scattering length is made increasingly
\\ ( , 205kb)
Date: Fri, 13 Jun 2008 16:49:49 GMT (760kb,D)

Title: Quantum Gas of Deeply Bound Ground State Molecules
Authors: Johann G. Danzl, Elmar Haller, Mattias Gustavsson, Manfred J. Mark,
   Russell Hart, Nadia Bouloufa, Olivier Dulieu, Helmut Ritsch, Hanns-Christoph
Categories: cond-mat.other
Comments: 4 figures
   We create an ultracold dense quantum gas of ground state molecules bound by
more than 1000 wavenumbers by stimulated two-photon transfer of molecules
associated on a Feshbach resonance from a Bose-Einstein condensate of cesium
atoms. The transfer efficiency exceeds 80%. In the process, the initial loose,
long-range electrostatic bond of the Feshbach molecule is coherently
transformed into a tight chemical bond. We demonstrate coherence of the
transfer in a Ramsey-type experiment and show that the molecular sample is not
heated during the transfer. Our results show that the preparation of a quantum
gas of molecules in arbitrary rovibrational states is possible and that the
creation of a Bose-Einstein condensate of molecules in their rovibronic ground
state is within reach.
\\ ( , 760kb)
Date: Fri, 13 Jun 2008 10:11:25 GMT (183kb)

Title: Schroedinger Cat: Entanglement test in a Micro-Macroscopic system
Authors: Francesco De Martini, Fabio Sciarrino, and Chiara Vitelli
Categories: quant-ph
Comments: 4 pages, 4 figures
   A Macro-state consisting of N= 3.5 x 10^4 photons in a quantum superposition
and entangled with a far apart single-photon state (Micro-state) is generated.
Precisely, an entangled photon pair is created by a nonlinear optical process,
then one photon of the pair is injected into an optical parametric amplifier
(OPA) operating for any input polarization state, i.e. into a phase-covariant
cloning machine. Such transformation establishes a connection between the
single photon and the multi particle fields. We then demonstrate the
non-separability of the bipartite system by adopting a local filtering
technique within a positive operator valued measurement.
\\ ( , 183kb)
Date: Fri, 13 Jun 2008 17:00:29 GMT (500kb)

Title: Loss of molecules in magneto-electrostatic traps due to nonadiabatic
Authors: Manuel Lara, Benjamin L. Lev and John L. Bohn
Categories: physics.atom-ph
Comments: 13 pages, 6 figures
   We analyze the dynamics of a paramagnetic, dipolar molecule in a generic
"magneto-electrostatic'' trap where both magnetic and electric fields may be
present. The potential energy that governs the dynamics of the molecules is
found using a reduced molecular model that incorporates the main features of
the system. We discuss the shape of the trapping potentials for different field
geometries, as well as the possibility of nonadiabatic transitions to untrapped
states, i.e., the analog of Majorana transitions in a quadrupole magnetic
atomic trap. Maximizing the lifetime of molecules in a trap is of great concern
in current experiments, and we assess the effect of nonadiabatic transitions on
obtainable trap lifetimes.
\\ ( , 500kb)
arXiv:0806.2125 (*cross-listing*)
Date: Thu, 12 Jun 2008 17:19:03 GMT (1383kb)

Title: An Atomic Gravitational Wave Interferometric Sensor (AGIS)
Authors: Savas Dimopoulos, Peter W. Graham, Jason M. Hogan, Mark A. Kasevich,
   Surjeet Rajendran
Categories: gr-qc astro-ph hep-ph hep-th physics.atom-ph
Comments: 41 pages, 19 figures
   We propose two distinct atom interferometer gravitational wave detectors, one
terrestrial and another satellite-based, utilizing the core technology of the
Stanford 10 m atom interferometer presently under construction. Each
configuration compares two widely separated atom interferometers run using
common lasers. The signal scales with the distance between the interferometers,
which can be large since only the light travels over this distance, not the
atoms. The terrestrial experiment with baseline ~1 km can operate with strain
sensitivity ~10^(-19) / Hz^(1/2) in the 1 Hz - 10 Hz band, inaccessible to
LIGO, and can detect gravitational waves from solar mass binaries out to
megaparsec distances. The satellite experiment with baseline ~1000 km can probe
the same frequency spectrum as LISA with comparable strain sensitivity
~10^(-20) / Hz^(1/2). The use of ballistic atoms (instead of mirrors) as
inertial test masses improves systematics coming from vibrations, acceleration
noise, and significantly reduces spacecraft control requirements. We analyze
the backgrounds in this configuration and discuss methods for controlling them
to the required levels.
\\ ( , 1383kb)
Date: Fri, 13 Jun 2008 21:28:51 GMT (64kb,D)

Title: Excitations of the One Dimensional Bose-Einstein Condensates in a Random
Authors: V. Gurarie, G. Refael, J. T. Chalker
Categories: cond-mat.dis-nn cond-mat.stat-mech
   We examine bosons hopping on a one-dimensional lattice in the presence of a
random potential at zero temperature. Bogoliubov excitations of the
Bose-Einstein condensate formed under such conditions are localized, with the
localization length diverging at low frequency as $\ell(\omega)\sim
1/\omega^\alpha$. We show that the well known result $\alpha=2$ applies only
for sufficiently weak random potential. As the random potential is increased
beyond a certain strength, $\alpha$ starts decreasing. At a critical strength
of the potential, when the system of bosons is at the transition from a
superfluid to an insulator, $\alpha=1$. This result is relevant for
understanding the behavior of the atomic Bose-Einstein condensates in the
presence of random potential, and of the disordered Josephson junction arrays.
\\ ( , 64kb)
Date: Fri, 13 Jun 2008 21:37:54 GMT (37kb)

Title: Fluctuation-Driven Vortex Fractionalization in Topological Superfluids
   of Cold Atoms
Authors: Jun Liang Song, Fei Zhou (UBC)
Categories: cond-mat.other
Comments: 4 pages, 2 figures
   We have studied fluctuation-driven vortex fractionalization and topological
order in 2D nematic superfluids of cold sodium atoms. Our Monte Carlo
simulations suggest that a softened pi-spin disclination be confined to a
half-quantum vortex when spin correlations are short ranged. Both this result
and direct calculations of winding-number operators indicate that a non-local
topological spin order emerges simultaneously as cold atoms become a superfluid
below a critical temperature. We have also obtained fluctuation-dependent
critical frequencies for half-quantum vortex nucleation in rotating optical
traps and discussed probing these excitations in experiments.
\\ ( , 37kb)
Date: Sat, 14 Jun 2008 17:26:52 GMT (16kb)

Title: Hidden order in bosonic gases confined in one dimensional optical
Authors: L. Amico, G. Mazzarella, S. Pasini, and F.S. Cataliotti
Categories: cond-mat.other cond-mat.stat-mech
Comments: 5 pages; 1 eps figure
   We analyze the effective Hamiltonian arising from a suitable power series
expansion of the overlap integrals of Wannier functions for confined bosonic
atoms in a $d$-dimensional optical lattice. For $d=1$, and for certain
constraint between the coupling constants, we construct an explicit relation
between the integrable spin-$S$ anisotropic Heisenberg and the bosonic models.
Therefore the latter result to be integrable by construction. The field theory
is governed by an anisotropic non linear sigma model with singlet and triplet
massive excitations; such a result holds also in the generic non-integrable
cases. The criticality of the bosonic system is investigated. The schematic
phase diagram is drawn. Our study is shedding light on the hidden symmetry of
the Haldane type for one dimensional bosons.
\\ ( , 16kb)
Date: Sun, 15 Jun 2008 08:24:29 GMT (487kb)

Title: Magnetic interactions of cold atoms with anisotropic conductors
Authors: T. David (1), Y. Japha (1), V. Dikovsky (1), R. Salem (1), C. Henkel
   (2), R. Folman (1) ((1) Ben-Gurion University of the Negev, Be'er Sheva,
   Israel. (2) Institut f\"ur Physik und Astronomie, Universit\"at Potsdam,
Categories: cond-mat.other cond-mat.mtrl-sci
Comments: Selected as a Highlight paper in the European Physical Journal D. The
   original publication, with better quality figure, is available at
DOI: 11.1140/epjd/e2008-00119-x
   We analyze atom-surface magnetic interactions on atom chips where the
magnetic trapping potentials are produced by current carrying wires made of
electrically anisotropic materials. We discuss a theory for time dependent
fluctuations of the magnetic potential, arising from thermal noise originating
from the surface. It is shown that using materials with a large electrical
anisotropy results in a considerable reduction of heating and decoherence rates
of ultra-cold atoms trapped near the surface, of up to several orders of
magnitude. The trap loss rate due to spin flips is expected to be significantly
reduced upon cooling the surface to low temperatures. In addition, the
electrical anisotropy significantly suppresses the amplitude of static spatial
potential corrugations due to current scattering within imperfect wires. Also
the shape of the corrugation pattern depends on the electrical anisotropy: the
preferred angle of the scattered current wave fronts can be varied over a wide
range. Materials, fabrication, and experimental issues are discussed, and
specific candidate materials are suggested.
\\ ( , 487kb)
Date: Mon, 16 Jun 2008 06:07:43 GMT (48kb)

Title: Magnetic ordering and quantum statistical effects in strongly repulsive
   Fermi-Fermi and Bose-Fermi mixtures
Authors: X.-W. Guan, M. T. Batchelor and J.-Y. Lee
Categories: cond-mat.stat-mech
Comments: 23 pages 5 figures
   We investigate magnetic properties and statistical effects in 1D strongly
repulsive two-component fermions and in a 1D mixture of strongly repulsive
polarized fermions and bosons. Universality in the characteristics of phase
transitions, magnetization and susceptibility in the presence of an external
magnetic field $H$ are analyzed from the exact thermodynamic Bethe ansatz
solution. We show explicitly that polarized fermions with a repulsive
interaction have antiferromagnetic behavior at zero temperature. A universality
class of linear field-dependent magnetization persists for weak and finite
strong interaction. The system is fully polarized when the external field
exceeds the critical value $H^F_c\approx \frac{8}{\gamma}E_F$, where $E_F$ is
the Fermi energy and $\gamma$ is the dimensionless interaction strength. In
contrast, the mixture of polarized fermions and bosons in an external field
exhibits square-root field-dependent magnetization in the vicinities of H=0 and
the critical value $H=H^M_c\approx \frac{16}{\gamma}E_F$. We find that a pure
boson phase occurs in the absence of the external field, fully-polarized
fermions and bosons coexist for $0<H<H^M_c$, and a fully-polarized fermion
phase occurs for $H\ge H_c^M$. This phase diagram for the Bose-Fermi mixture is
reminiscent of weakly attractive fermions with population imbalance, where the
interacting fermions with opposite spins form singlet pairs.
\\ ( , 48kb)
Date: Mon, 16 Jun 2008 13:35:36 GMT (203kb)

Title: Trionic and quartetting phases in one-dimensional multicomponent
   ultracold fermions
Authors: P. Lecheminant, P. Azaria, E. Boulat, S. Capponi, G. Roux, S. R. White
Categories: cond-mat.str-el
Comments: Contribution to the SOTANCP 2008 workshop
   We investigate the possible formation of a molecular condensate, which might
be, for instance, the analogue of the alpha condensate of nuclear physics, in
the context of multicomponent cold atoms fermionic systems. A simple
paradigmatic model of N-component fermions with contact interactions loaded
into a one-dimensional optical lattice is studied by means of low-energy and
numerical approaches. For attractive interaction, a quasi-long-range molecular
superfluid phase, formed from bound-states made of N fermions, emerges at low
density. We show that trionic and quartetting phases, respectively for N=3,4,
extend in a large domain of the phase diagram and are robust against small
symmetry-breaking perturbations.
\\ ( , 203kb)
Date: Mon, 16 Jun 2008 17:01:54 GMT (146kb,D)

Title: Low-energy molecular collisions in a permanent magnetic trap
Authors: Brian C. Sawyer, Benjamin K. Stuhl, Dajun Wang, Mark Yeo, Jun Ye
Categories: physics.atom-ph physics.atm-clus physics.chem-ph
Comments: 4 pages, 4 figures
   Cold, neutral hydroxyl radicals are Stark decelerated and confined within a
magnetic trap consisting of two permanent ring magnets. The OH molecules are
trapped in the ro-vibrational ground state at a density of $\sim10^{6}$
cm$^{-3}$ and temperature of 70 mK. Collisions between the trapped OH sample
and supersonic beams of atomic He and molecular D$_{2}$ are observed and
absolute collision cross sections measured. The He--OH and D$_{2}$--OH
center-of-mass collision energies are tuned from 60 cm$^{-1}$ to 230 cm$^{-1}$
and 145 cm$^{-1}$ to 510 cm$^{-1}$, respectively, yielding evidence of reduced
He--OH inelastic cross sections at energies below 84 cm$^{-1}$, the OH ground
rotational level spacing.
\\ ( , 146kb)
Date: Mon, 16 Jun 2008 17:23:28 GMT (36kb)

Title: Graduate Quantum Mechanics Reform
Authors: L. D. Carr and S. B. McKagan
Categories: physics.ed-ph
Comments: submitted to American Journal of Physics
   We address four main areas in which graduate quantum mechanics education in
the U.S. can be improved: course content; textbook; teaching methods; and
assessment tools. We report on a three year longitudinal study at the Colorado
School of Mines using innovations in all four of these areas. In particular, we
have modified the content of the course to reflect progress in the field in the
last 50 years, use modern textbooks that include such content, incorporate a
variety of teaching techniques based on physics education research, and used a
variety of assessment tools to study the effectiveness of these reforms. We
present a new assessment tool, the Graduate Quantum Mechanics Conceptual
Survey, and further testing of a previously developed assessment tool, the
Quantum Mechanics Conceptual Survey (QMCS). We find that graduate students
respond well to research-based techniques that have previously been tested
mainly in introductory courses, and that they learn a great deal of the new
content introduced in each version of the course. We also find that students'
ability to answer conceptual questions about graduate quantum mechanics is
highly correlated with their ability to solve calculational problems on the
same topics. On the other hand, we find that students' understanding of basic
undergraduate quantum mechanics concepts at the modern physics level is not
improved by instruction at the graduate level.
\\ ( , 36kb)
arXiv:0806.2583 (*cross-listing*)
Date: Mon, 16 Jun 2008 13:56:08 GMT (48kb)

Title: Avoided crossings between bound states of ultracold Cesium dimers
Authors: Jeremy M. Hutson, Eite Tiesinga, Paul S. Julienne
Categories: physics.chem-ph physics.atom-ph
Comments: 11 pages, 9 figures
   We present an efficient new computational method for calculating the binding
energies of the bound states of ultracold alkali-metal dimers in the presence
of magnetic fields. The method is based on propagation of coupled differential
equations and does not use a basis set for the interatomic distance coordinate.
It is much more efficient than the previous method based on a radial basis set
and allows many more spin channels to be included. This is particularly
important in the vicinity of avoided crossings between bound states. We
characterize a number of different avoided crossings in Cs_2 and compare our
converged calculations with experimental results. Small but significant
discrepancies are observed in both crossing strengths and level positions,
especially for levels with l symmetry (rotational angular momentum L=8). The
discrepancies should allow the development of improved potential models in the
\\ ( , 48kb)
Date: Mon, 16 Jun 2008 20:20:47 GMT (580kb)

Title: Universal Fermi gases in mixed dimensions
Authors: Yusuke Nishida and Shina Tan
Categories: cond-mat.other
Comments: 4 pages, 7 figures
Report-no: INT-PUB 08-11
   We investigate a two-species Fermi gas in which one species is confined in a
two-dimensional plane (2D) or one-dimensional line (1D) while the other is free
in the three-dimensional space (3D). We discuss the realization of such a
system with the interspecies interaction tuned to resonance. When the mass
ratio is in the range 0.0351<m_2D/m_3D<6.35 for the 2D-3D mixture or
0.00646<m_1D/m_3D<2.06 for the 1D-3D mixture, the resulting system is stable
against the Efimov effect and has universal properties. We calculate key
quantities in the many-body phase diagram. Other possible scale-invariant
systems with short-range few-body interactions are also elucidated.
\\ ( , 580kb)
Date: Tue, 17 Jun 2008 09:40:24 GMT (875kb)

Title: Quantum Turbulence
Authors: Makoto Tsubota
Categories: cond-mat.other
Comments: 13 pages, 5 figures, Review article to appear in J. Phys. Soc. Jpn
   The present article reviews the recent developments in the physics of quantum
turbulence. Quantum turbulence (QT) was discovered in superfluid $^4$He in the
1950s, and the research has tended toward a new direction since the mid 90s.
The similarities and differences between quantum and classical turbulence have
become an important area of research. QT is comprised of quantized vortices
that are definite topological defects, being expected to yield a model of
turbulence that is much simpler than the classical model. The general
introduction of the issue and a brief review on classical turbulence are
followed by a description of the dynamics of quantized vortices. Then, we
discuss the energy spectrum of QT at very low temperatures. At low wavenumbers,
the energy is transferred through the Richardson cascade of quantized vortices,
and the spectrum obeys the Kolmogorov law, which is the most important
statistical law in turbulence; this classical region shows the similarity to
conventional turbulence. At higher wavenumbers, the energy is transferred by
the Kelvin-wave cascade on each vortex. This quantum regime depends strongly on
the nature of each quantized vortex. The possible dissipation mechanism is
discussed. Finally, important new experimental studies, which include
investigations into temperature-dependent transition to QT, dissipation at very
low temperatures, QT created by vibrating structures, and visualization of QT,
are reviewed. The present article concludes with a brief look at QT in atomic
Bose-Einstein condensates.
\\ ( , 875kb)
Date: Tue, 17 Jun 2008 15:00:22 GMT (283kb)

Title: Quantum Phase Diagram of Bosons in Optical Lattices
Authors: Francisco Ednilson A. dos Santos and Axel Pelster
Categories: cond-mat.stat-mech
Comments: Author Information under
   We work out two different analytical methods for calculating the boundary of
the Mott insulator-superfluid (MI-SF) quantum phase transition for scalar
bosons in cubic optical lattices of arbitrary dimension at zero temperature
which improve upon the seminal mean-field result. The first one is a
variational method, which is inspired by variational perturbation theory,
whereas the second one is based on the field-theoretic concept of effective
potential. Within both analytical approaches we achieve a considerable
improvement of the location of the MI-SF quantum phase transition for the first
Mott lobe in excellent agreement with recent numerical results from Quantum
Monte-Carlo simulations in two and three dimensions. Thus, our analytical
results for the whole quantum phase diagram can be regarded as being
essentially exact for all practical purposes.
\\ ( , 283kb)
Date: Tue, 17 Jun 2008 20:00:10 GMT (8kb)

Title: Microscopic diagonal entropy and its connection to basic thermodynamic
Authors: Roman Barankov and Anatoli Polkovnikov
Categories: cond-mat.stat-mech
Comments: 4+ pages, no figures
   We define the diagonal entropy (or simply d-entropy) for an arbitrary closed
system as $S_d=-\sum_n \rho_{nn}\ln \rho_{nn}$, where the sum is taken over the
instantaneous energy basis states. In equilibrium this entropy coincides with
the conventional von Neumann entropy $S_n=-{\rm Tr} \rho\ln\rho$. However,
d-entropy is not conserved in time. One can show that if the initial density
matrix is diagonal then for arbitrary process $S_d(t)\geq S_d(0)$. Moreover if
the system is initially in thermal equilibrium characterized by temperature $T$
then for arbitrary processes, which infinitesimally change the state of the
system, the d-entropy satisfies the first law of thermodynamics: $\Delta E=
T\Delta S_d - \sum_j (\partial E_j/\partial \lambda_j)_{S_d}\Delta \lambda_j$,
where $\lambda_j$ are external parameters. If $\lambda$ stands for the volume
$V$ then one recovers the most conventional form of the first law $\Delta E =
T\Delta S_d - P\Delta V$.
\\ ( , 8kb)
Date: Tue, 17 Jun 2008 20:08:33 GMT (51kb)

Title: Boson Hubbard model with weakly coupled Fermions
Authors: R. M. Lutchyn, S. Tewari, and S. Das Sarma
Categories: cond-mat.str-el cond-mat.supr-con
Comments: 4 pages, 2 figures
   Using an imaginary-time path integral approach, we develop the perturbation
theory suited to the boson Hubbard model, and apply it to calculate the effects
of a dilute gas of spin-polarized fermions weakly interacting with the bosons.
The full theory captures both the static and the dynamic effects of the
fermions on the generic superfluid-insulator phase diagram. We find that, in a
homogenous system described by a single-band boson Hubbard Hamiltonian, the
intrinsic perturbative effect of the fermions is to generically suppress the
insulating lobes and to enhance the superfluid phase.
\\ ( , 51kb)
Date: Wed, 18 Jun 2008 10:07:15 GMT (654kb)

Title: Ultracold dipolar gas in an optical lattice: the fate of metastable
Authors: C. Trefzger, C. Menotti, and M. Lewenstein
Categories: cond-mat.other
Comments: 15 pages, 19 figures
   We study the physics of ultracold dipolar bosons in optical lattices. We show
that dipole-dipole interactions lead to the appearance of many insulating
metastable states. We study the stability and lifetime of these states using a
generalization of the instanton theory. We investigate also possibilities to
prepare, control and manipulate these states using time dependent superlattice
modifications and modulations. We show that the transfer from one metastable
configuration to another necessarily occurs via superfluid states, but can be
controlled fully on the quantum level. We show how the metastable states can be
created in the presence of the harmonic trap. Our findings open the way toward
applications of the metastable states as quantum memories.
\\ ( , 654kb)
Date: Wed, 18 Jun 2008 10:59:22 GMT (30kb)

Title: Systematic Semiclassical Expansion for Harmonically Trapped Ideal Bose
Authors: Ben Kl\"under and Axel Pelster
Categories: cond-mat.stat-mech
Comments: Author Information under
   Using a field-theoretic approach, we systematically generalize the usual
semiclassical approximation for a harmonically trapped ideal Bose gas in such a
way that its range of applicability is essentially extended. With this we can
analytically calculate thermodynamic properties even for small particle
numbers. In particular, it now becomes possible to determine the critical
temperature as well as the temperature dependence of both heat capacity and
condensate fraction in low-dimensional traps, where the standard semiclassical
approximation is not even applicable.
\\ ( , 30kb)
Date: Wed, 18 Jun 2008 07:55:45 GMT (461kb)

Title: Surface-induced heating of cold polar molecules
Authors: Stefan Yoshi Buhmann, M. R. Tarbutt, Stefan Scheel, E. A. Hinds
Categories: quant-ph
Comments: 17 pages, 7 figures
   We study the rotational and vibrational heating of diatomic molecules placed
near a surface at finite temperature on the basis of macroscopic quantum
electrodynamics. The internal molecular evolution is governed by transition
rates that depend on both temperature and position. Analytical and numerical
methods are used to investigate the heating of several relevant molecules near
various surfaces. We determine the critical distances at which the surface
itself becomes the dominant source of heating and we investigate the transition
between the long-range and short-range behaviour of the heating rates. A simple
formula is presented that can be used to estimate the surface-induced heating
rates of other molecules of interest. We also consider how the heating depends
on the thickness and composition of the surface.
\\ ( , 461kb)
Date: Wed, 18 Jun 2008 18:46:10 GMT (955kb,D)

Title: Dimer-dimer collisions at finite energies in two-component Fermi gases
Authors: J. P. D'Incao, Seth T. Rittenhouse, N. P. Mehta, Chris H. Greene
Categories: physics.atom-ph
Comments: 4.1 pages, 3 figures
   We introduce a major theoretical generalization of existing techniques for
handling the three-body problem that accurately describes the interactions
among four fermionic atoms. Application to a two-component Fermi gas accurately
determines dimer-dimer scattering parameters at finite energies and gives
deeper insight into the corresponding many-body phenomena. To account for
finite temperature effects, we calculate the energy-dependent complex
dimer-dimer scattering length, which includes contributions from elastic and
inelastic collisions. Our results indicate that strong finite-energy effects
are crucial for understanding the physics in the crossover regime for typical
experimental conditions. While our results for dimer-dimer relaxation are
consistent with experiment, they disagree with a previously published
theoretical result.
\\ ( , 955kb)
Date: Thu, 19 Jun 2008 07:39:02 GMT (25kb)

Title: Evolution of fragmented states
Authors: G. S. Paraoanu
Categories: cond-mat.other
Comments: 4 pages
   We consider the problem of evolution of the many-body state of a weakly
interacting system of bosons in an initially fragmented (Fock) state. We show
that the state at any time can be expressed as a continuous superposition of an
infinite number of Gross-Pitaevskii states.
\\ ( , 25kb)
Date: Wed, 18 Jun 2008 23:42:47 GMT (341kb)

Title: The initial momentum dependence of the quantum resonance in the
   delta-kicked rotor
Authors: J-A. Currivan, A. Ullah and M.D. Hoogerland
Categories: quant-ph
Comments: 4 pages, 4 figures
   The influence of an initial momentum on the appearance of ``quantum
resonances'' in the delta-kicked rotor system is explored experimentally. We
show than for certain initial momenta, a resonance can be negated entirely,
whereas at others a resonance can be made to appear. At a larger number of
kicks, all resonances are shown to narrow. We compare our results to numerical
simulations as well as analytical theory.
\\ ( , 341kb)
Date: Thu, 19 Jun 2008 02:58:35 GMT (443kb)

Title: Homodyne measurements and detection of continuous variable entanglement
   with mesoscopic numbers of bosons
Authors: A. J. Ferris, M. K. Olsen, E. G. Cavalcanti, and M. J. Davis
Categories: quant-ph
Comments: 4 Pages, 2 Figures
   We propose three criteria for continuous variable entanglement between two
many-particle systems. We demonstrate that failing to account for the quantum
nature of the phase reference required for measurements can lead to mistakenly
identifying the presence of entanglement in numerical simulations with 100
particles. We further show that large number fluctuations do not prevent the
observation of entanglement. Our results are important for potential quantum
information experiments with realistic Bose-Einstein condensates or in optics
with small numbers of photons.
\\ ( , 443kb)
Date: Thu, 19 Jun 2008 18:50:08 GMT (986kb)

Title: Light-pulse atom interferometry
Authors: Jason M. Hogan, David M. S. Johnson and Mark A. Kasevich
Categories: physics.atom-ph
Comments: 38 pages, 13 figures. To appear in the Proceedings of the
   International Summer School of Physics "Enrico Fermi" on Atom Optics and
   Space Physics (Varenna, July 2007)
   The light-pulse atom interferometry method is reviewed. Applications of the
method to inertial navigation and tests of the Equivalence Principle are
\\ ( , 986kb)

The replacements:

replaced with revised version Fri, 13 Jun 2008 13:17:12 GMT (83kb)

Title: Superfluidity versus Anderson localization in a dilute Bose gas
Authors: T. Paul, P. Schlagheck, P. Leboeuf, and N. Pavloff
Categories: cond-mat.other
Comments: 4 pages, 3 figures, final published version
Journal-ref: Phys. Rev. Lett. 98, 210602 (2007)
\\ ( , 83kb)
replaced with revised version Fri, 13 Jun 2008 17:55:27 GMT (672kb)

Title: Determination of the Fermion Pair Size in a Resonantly Interacting
Authors: Christian H. Schunck, Yong-il Shin, Andre Schirotzek, and Wolfgang
Categories: cond-mat.supr-con cond-mat.str-el
Comments: 8 pages, 7 figures; Figures updated; New Figures added; Updated
   discussion of fit functions
\\ ( , 672kb)
replaced with revised version Fri, 13 Jun 2008 18:15:52 GMT (432kb)

Title: Correlation Effects in Ultracold Two-Dimensional Bose Gases
Authors: Lih-King Lim, C. Morais Smith, and H. T. C. Stoof
Categories: cond-mat.stat-mech
Comments: Minor changes in the text, references added
\\ ( , 432kb)
replaced with revised version Mon, 16 Jun 2008 15:57:03 GMT (788kb)

Title: Phase-slip induced dissipation in an atomic Bose-Hubbard system
Authors: D. McKay, M. White, M. Pasienski, and B. DeMarco
Categories: cond-mat.other
Comments: published in Nature 453, 76 (2008)
\\ ( , 788kb)
replaced with revised version Mon, 16 Jun 2008 09:45:41 GMT (12kb)

Title: Virial theorems for trapped cold atoms
Authors: F\'elix Werner (LKB - Lhomond)
Categories: cond-mat.other
Comments: Revised and extended version
\\ ( , 12kb)
replaced with revised version Mon, 16 Jun 2008 15:43:02 GMT (155kb)

Title: Topological Zero modes in fermionic condensate phases on the honeycomb
Authors: Doron L. Bergman and Karyn Le Hur
Categories: cond-mat.supr-con
\\ ( , 155kb)
replaced with revised version Mon, 16 Jun 2008 18:55:31 GMT (8kb)

Title: Microscopic expression for the heat in the adiabatic basis
Authors: Anatoli Polkovnikov
Categories: cond-mat.stat-mech
Comments: 4+, no figures. Revised version. New title. Added references to the
   prior work
\\ ( , 8kb)
replaced with revised version Mon, 16 Jun 2008 10:14:02 GMT (213kb)

Title: Number-conserving phase-space dynamics of the Bose-Hubbard dimer beyond
   the mean-field approximation
Authors: F. Trimborn, D. Witthaut, and H. J. Korsch
Categories: quant-ph
Comments: Enlarged and revised version (12 pages, 11 figures)
\\ ( , 213kb)
replaced with revised version Mon, 16 Jun 2008 14:11:42 GMT (72kb)

Title: Atom interferometry using wavepackets with constant spatial separations
Authors: Edward J. Su, Saijun Wu, Mara Prentiss
Categories: physics.atom-ph
\\ ( , 72kb)
replaced with revised version Tue, 17 Jun 2008 11:08:34 GMT (143kb)

Title: Free expansion of a Lieb-Liniger gas: Asymptotic form of the wave
Authors: D. Juki\'c, R. Pezer, T. Gasenzer, H. Buljan
Categories: cond-mat.other
Comments: Revised version, new figure
Report-no: HD-THEP-08-10, NSF-KITP-08-60
\\ ( , 143kb)
replaced with revised version Tue, 17 Jun 2008 14:23:37 GMT (127kb)

Title: Vortex dynamics in trapped Bose-Einstein condensate
Authors: E. J. M. Madarassy and C. F. Barenghi
Categories: cond-mat.stat-mech
Comments: 16 pages, 18 figures, published in JLTP
\\ ( , 127kb)
replaced with revised version Tue, 17 Jun 2008 03:40:40 GMT (710kb)

Title: Storing images in warm atomic vapor
Authors: M. Shuker, O. Firstenberg, R. Pugatch, A. Ron, N. Davidson
Categories: quant-ph
Journal-ref: Phys. Rev Lett. 100, 223601 (2008)
DOI: 10.1103/PhysRevLett.100.223601
\\ ( , 710kb)
replaced with revised version Wed, 18 Jun 2008 11:42:07 GMT (516kb)

Title: Synchronized and Desynchronized Phases of Exciton-Polariton Condensates
   in the Presence of Disorder
Authors: A. Baas, K. G. Lagoudakis, M. Richard, R. Andre, Le Si Dang, B.
Categories: cond-mat.other
Comments: 11 pages, 4 figures,corrected typos, added figures
Journal-ref: Phys. Rev. Lett. 100, 170401 (2008)
\\ ( , 516kb)
replaced with revised version Wed, 18 Jun 2008 15:42:47 GMT (239kb)

Title: Anisotropic scattering of Bogoliubov excitations
Authors: Christopher Gaul and Cord Axel M\"uller
Categories: cond-mat.other
Comments: 5 pages, 5 figures
Journal-ref: Europhys. Lett. 83, 10006 (2008)
DOI: 10.1209/0295-5075/83/10006
\\ ( , 239kb)
replaced with revised version Wed, 18 Jun 2008 06:56:40 GMT (66kb)

Title: Goos-H\"{a}nchen-Like Shifts in Atom Optics
Authors: Jianhua Huang, Zhenglu Duan, Hong Y. Ling, and Weiping Zhang
Categories: quant-ph
Comments: 7 pages, 4 figures
DOI: 10.1103/PhysRevA.77.063608
\\ ( , 66kb)
replaced with revised version Wed, 18 Jun 2008 09:07:53 GMT (89kb)

Title: Two-particle states in the Hubbard model
Authors: Manuel Valiente, David Petrosyan
Categories: quant-ph math-ph math.MP
Comments: 3 pages, 1 figure
\\ ( , 89kb)
replaced with revised version Wed, 18 Jun 2008 21:18:58 GMT (218kb)

Title: Bose Hubbard model in the presence of Ohmic dissipation
Authors: Denis Dalidovich and Malcolm P. Kennett
Categories: cond-mat.supr-con cond-mat.str-el
Comments: 5 pages, 2 figures. Error found in v1, now corrected, leads to
   qualitative changes in results
\\ ( , 218kb)
replaced with revised version Thu, 19 Jun 2008 14:51:30 GMT (128kb,D)

Title: Final-state effects in the radio frequency spectrum of strongly
   interacting fermions
Authors: Sourish Basu, Erich J. Mueller
Categories: cond-mat.str-el cond-mat.other
Comments: 4 pages, 4 figures
\\ ( , 128kb)
replaced with revised version Thu, 19 Jun 2008 00:13:50 GMT (204kb)

Title: Berry Phase Effect on Exciton Transport and Bose Einstein Condensate
Authors: Wang Yao, Qian Niu
Categories: cond-mat.mes-hall
Comments: 4 pages, 2 figures
\\ ( , 204kb)
replaced with revised version Thu, 19 Jun 2008 14:48:37 GMT (403kb)

Title: Collisional Properties of a Polarized Fermi Gas with Resonant
Authors: G. M. Bruun, A. Recati, C. J. Pethick, H. Smith and S. Stringari
Categories: cond-mat.stat-mech
Comments: 4 pages, 2 figures. Nordita preprint 2008-14. Paper slightly revised
Journal-ref: Phys. Rev. Lett. 100, 240406 (2008)
DOI: 10.1103/PhysRevLett.100.240406
\\ ( , 403kb)
replaced with revised version Thu, 19 Jun 2008 13:01:05 GMT (165kb)

Title: Time reversal of Bose-Einstein condensates
Authors: J. Martin, B. Georgeot and D. L. Shepelyansky
Categories: cond-mat.stat-mech nlin.CD quant-ph
Comments: 4 pages, 5 figures. References and discussion added. Research done at
\\ ( , 165kb)
replaced with revised version Thu, 19 Jun 2008 14:42:33 GMT (377kb)

Title: Thermodynamics of a trapped unitary Fermi gas
Authors: R. Haussmann and W. Zwerger
Categories: cond-mat.stat-mech
Comments: 9 pages, 5 figures
Report-no: KN-08-05
\\ ( , 377kb)

Till next time,

Dr M. J. Davis,               Senior Lecturer in Physics
School of Physical Sciences,  email:
University of Queensland,     ph   : +61 7 334 69824
Brisbane, QLD 4072,           fax  : +61 7 336 51242
Matt's arXiv selection: weekly summary of cold-atom papers from
Legal stuff: Unless stated otherwise, this e-mail represents only the
views of the sender and not the views of the University of Queensland
Received on Fri Jul 04 2008 - 08:31:03 EST

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