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

Date: Sun, 29 Jun 2008 21:10:46 +1000

Date: Sun, 29 Jun 2008 21:10:46 +1000

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

Hi,

This week there were 28 new preprints and 22 replacements:

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arXiv:0806.2242

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.

\\ ( http://arxiv.org/abs/0806.2242 , 571kb)

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arXiv:0806.2277

Date: Fri, 13 Jun 2008 16:15:09 GMT (205kb)

Title: Exact Relations for a Strongly-interacting Fermi Gas near a Feshbach

Resonance

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

large.

\\ ( http://arxiv.org/abs/0806.2277 , 205kb)

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arXiv:0806.2284

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

Naegerl

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.

\\ ( http://arxiv.org/abs/0806.2284 , 760kb)

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arXiv:0806.2218

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.

\\ ( http://arxiv.org/abs/0806.2218 , 183kb)

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arXiv:0806.2245

Date: Fri, 13 Jun 2008 17:00:29 GMT (500kb)

Title: Loss of molecules in magneto-electrostatic traps due to nonadiabatic

transitions

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.

\\ ( http://arxiv.org/abs/0806.2245 , 500kb)

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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.

\\ ( http://arxiv.org/abs/0806.2125 , 1383kb)

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arXiv:0806.2322

Date: Fri, 13 Jun 2008 21:28:51 GMT (64kb,D)

Title: Excitations of the One Dimensional Bose-Einstein Condensates in a Random

Potential

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.

\\ ( http://arxiv.org/abs/0806.2322 , 64kb)

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arXiv:0806.2323

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.

\\ ( http://arxiv.org/abs/0806.2323 , 37kb)

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arXiv:0806.2378

Date: Sat, 14 Jun 2008 17:26:52 GMT (16kb)

Title: Hidden order in bosonic gases confined in one dimensional optical

lattices

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.

\\ ( http://arxiv.org/abs/0806.2378 , 16kb)

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arXiv:0806.2427

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,

Germany.)

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

http://www.epj.org

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.

\\ ( http://arxiv.org/abs/0806.2427 , 487kb)

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arXiv:0806.2499

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.

\\ ( http://arxiv.org/abs/0806.2499 , 48kb)

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arXiv:0806.2556

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.

\\ ( http://arxiv.org/abs/0806.2556 , 203kb)

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arXiv:0806.2624

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.

\\ ( http://arxiv.org/abs/0806.2624 , 146kb)

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arXiv:0806.2628

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.

\\ ( http://arxiv.org/abs/0806.2628 , 36kb)

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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

future.

\\ ( http://arxiv.org/abs/0806.2583 , 48kb)

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arXiv:0806.2668

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.

\\ ( http://arxiv.org/abs/0806.2668 , 580kb)

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arXiv:0806.2737

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.

\\ ( http://arxiv.org/abs/0806.2737 , 875kb)

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arXiv:0806.2812

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

http://www.theo-phys.uni-essen.de/tp/ags/pelster_dir

\\

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.

\\ ( http://arxiv.org/abs/0806.2812 , 283kb)

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arXiv:0806.2862

Date: Tue, 17 Jun 2008 20:00:10 GMT (8kb)

Title: Microscopic diagonal entropy and its connection to basic thermodynamic

relations

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$.

\\ ( http://arxiv.org/abs/0806.2862 , 8kb)

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arXiv:0806.2865

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.

\\ ( http://arxiv.org/abs/0806.2865 , 51kb)

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arXiv:0806.2950

Date: Wed, 18 Jun 2008 10:07:15 GMT (654kb)

Title: Ultracold dipolar gas in an optical lattice: the fate of metastable

states

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.

\\ ( http://arxiv.org/abs/0806.2950 , 654kb)

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arXiv:0806.2960

Date: Wed, 18 Jun 2008 10:59:22 GMT (30kb)

Title: Systematic Semiclassical Expansion for Harmonically Trapped Ideal Bose

Gases

Authors: Ben Kl\"under and Axel Pelster

Categories: cond-mat.stat-mech

Comments: Author Information under

http://www.theo-phys.uni-essen.de/tp/ags/pelster_dir

\\

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.

\\ ( http://arxiv.org/abs/0806.2960 , 30kb)

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arXiv:0806.2913

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.

\\ ( http://arxiv.org/abs/0806.2913 , 461kb)

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arXiv:0806.3062

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.

\\ ( http://arxiv.org/abs/0806.3062 , 955kb)

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arXiv:0806.3143

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.

\\ ( http://arxiv.org/abs/0806.3143 , 25kb)

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arXiv:0806.3107

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.

\\ ( http://arxiv.org/abs/0806.3107 , 341kb)

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\\

arXiv:0806.3120

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.

\\ ( http://arxiv.org/abs/0806.3120 , 443kb)

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\\

arXiv:0806.3261

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

discussed.

\\ ( http://arxiv.org/abs/0806.3261 , 986kb)

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The replacements:

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\\

arXiv:cond-mat/0702591

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)

\\ ( http://arxiv.org/abs/cond-mat/0702591 , 83kb)

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\\

arXiv:0802.0341

replaced with revised version Fri, 13 Jun 2008 17:55:27 GMT (672kb)

Title: Determination of the Fermion Pair Size in a Resonantly Interacting

Superfluid

Authors: Christian H. Schunck, Yong-il Shin, Andre Schirotzek, and Wolfgang

Ketterle

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

Comments: 8 pages, 7 figures; Figures updated; New Figures added; Updated

discussion of fit functions

\\ ( http://arxiv.org/abs/0802.0341 , 672kb)

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\\

arXiv:0804.2600

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

\\ ( http://arxiv.org/abs/0804.2600 , 432kb)

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arXiv:0708.3074

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)

\\ ( http://arxiv.org/abs/0708.3074 , 788kb)

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\\

arXiv:0803.3277

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

\\ ( http://arxiv.org/abs/0803.3277 , 12kb)

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\\

arXiv:0806.0379

replaced with revised version Mon, 16 Jun 2008 15:43:02 GMT (155kb)

Title: Topological Zero modes in fermionic condensate phases on the honeycomb

lattice

Authors: Doron L. Bergman and Karyn Le Hur

Categories: cond-mat.supr-con

\\ ( http://arxiv.org/abs/0806.0379 , 155kb)

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arXiv:0806.0620

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

\\ ( http://arxiv.org/abs/0806.0620 , 8kb)

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\\

arXiv:0802.1142

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)

\\ ( http://arxiv.org/abs/0802.1142 , 213kb)

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\\

arXiv:physics/0701018

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

\\ ( http://arxiv.org/abs/physics/0701018 , 72kb)

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\\

arXiv:0804.2580

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

functions

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

\\ ( http://arxiv.org/abs/0804.2580 , 143kb)

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\\

arXiv:0806.2077

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

\\ ( http://arxiv.org/abs/0806.2077 , 127kb)

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\\

arXiv:0707.3707

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

\\ ( http://arxiv.org/abs/0707.3707 , 710kb)

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\\

arXiv:0712.2121

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.

Deveaud-Pledran

Categories: cond-mat.other

Comments: 11 pages, 4 figures,corrected typos, added figures

Journal-ref: Phys. Rev. Lett. 100, 170401 (2008)

\\ ( http://arxiv.org/abs/0712.2121 , 516kb)

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\\

arXiv:0802.4366

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

\\ ( http://arxiv.org/abs/0802.4366 , 239kb)

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\\

arXiv:0802.2149

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

\\ ( http://arxiv.org/abs/0802.2149 , 66kb)

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\\

arXiv:0805.1812

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

\\ ( http://arxiv.org/abs/0805.1812 , 89kb)

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\\

arXiv:0711.1563

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

\\ ( http://arxiv.org/abs/0711.1563 , 218kb)

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\\

arXiv:0712.1007

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

\\ ( http://arxiv.org/abs/0712.1007 , 128kb)

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\\

arXiv:0801.1103

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

\\ ( http://arxiv.org/abs/0801.1103 , 204kb)

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\\

arXiv:0804.1885

replaced with revised version Thu, 19 Jun 2008 14:48:37 GMT (403kb)

Title: Collisional Properties of a Polarized Fermi Gas with Resonant

Interactions

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

\\ ( http://arxiv.org/abs/0804.1885 , 403kb)

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\\

arXiv:0804.3514

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

http://www.quantware.ups-tlse.fr/

\\ ( http://arxiv.org/abs/0804.3514 , 165kb)

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\\

arXiv:0805.3226

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

\\ ( http://arxiv.org/abs/0805.3226 , 377kb)

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Till next time,

Matt.

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

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