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

Date: Mon, 8 Nov 2010 23:12:00 +1000

Date: Mon, 8 Nov 2010 23:12:00 +1000

Dear subscribers,

This week's selection was compiled by a Mike Garrett, and contains 33 new

abstracts and 23 replacements.

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arXiv:1009.4646 (*cross-listing*)

Date: Thu, 23 Sep 2010 15:54:20 GMT (20kb)

Title: Dynamical simulation of integrable and non-integrable models in the

Heisenberg picture

Authors: Dominik Muth, Razmik Unanyan, and Michael Fleischhauer

Categories: quant-ph cond-mat.other

Comments: 4 pages, 2 figures

\\

The numerical simulation of quantum many-body dynamics is typically limited

by the linear growth of entanglement with time requiring exponentially

increasing computational ressources to reach a given accuracy. Recently

numerical studies have shown, however, that for 1D Bethe-integrable models the

simulation of local operators in the Heisenberg picture can be much more

efficient as the corresponding operator-space entanglement growsonly

logarithmically with time. Using the spin-1/2 XX chain as generic example of an

integrabel model that can be mapped to free particles, we here provide a simple

explanation of this behaviour. Furthermore we show that the same reduction of

numerical complexity applies to operators that have a high-temperature auto

correlation function which decays slower than exponential, i.e. with a power

law. This is amongst others the case for models where the Blombergen-De Gennes

conjecture of high-temperature diffusive dynamics holds. Thus efficient

simulability may already be implied by a single conservation law (like that of

total magnetization), as we will illustrate numerically for the spin-1 XXZ

model.

\\ ( http://arxiv.org/abs/1009.4646 , 20kb)

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arXiv:1010.1534

Date: Thu, 7 Oct 2010 20:00:21 GMT (656kb,D)

Title: Inter-band coupling induced novel condensates in a double-well lattice

Authors: Qi Zhou, J. V. Porto, and S. Das Sarma

Categories: cond-mat.quant-gas

Comments: 4 pages, 2 figures

\\

We predict novel inter-band physics for bosons in a double-well lattice. An

intrinsic coupling between the s and px band due to interaction gives rise to

larger Mott regions on the phase diagram at even fillings than the ones at odd

fillings. On the other hand, the ground state can form various types of

condensates, including a mixture of single-particle condensates of both bands,

a mixture of a single-particle condensate of one band and a pair-condensate of

the other band, and a pair-condensate composed of one particle from one band

and one hole from the other band. The predicted phenomena should be observable

in current experiments on double-well optical lattices.

\\ ( http://arxiv.org/abs/1010.1534 , 656kb)

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arXiv:1010.1643

Date: Fri, 8 Oct 2010 10:05:49 GMT (891kb)

Title: Ground states of trapped spin-1 condensates in magnetic field

Authors: Michal Matuszewski

Categories: cond-mat.quant-gas

\\

We consider a spin-1 Bose-Einstein condensate trapped in a harmonic potential

under the influence of a homogeneous magnetic field. We investigate spatial and

spin structure of the mean-field ground states under constraints on the number

of atoms and the total magnetization. We show that the trapping potential can

make the antiferromagnetic condensate separate into three, and ferromagnetic

condensate into two distinct phases. In the ferromagnetic case, the

magnetization is located in the center of the harmonic trap, while in the

antiferromagnetic case magnetized phases appear in the outer regions. We

describe how the transition from the Thomas-Fermi regime to the single-mode

approximation regime with decreasing number of atoms results in the

disappearance of the domains. We suggest that the ground states can be created

in experiment by adiabatically changing the magnetic field strength.

\\ ( http://arxiv.org/abs/1010.1643 , 891kb)

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arXiv:1010.1657

Date: Fri, 8 Oct 2010 10:47:39 GMT (619kb)

Title: Quantum interference in a four-level system of a $^{87}\mathrm{Rb}$

atom: Effects of spontaneously generated coherence

Authors: Dongsheng Wang and Yujun Zheng

Categories: quant-ph physics.atom-ph

Comments: 9 pages, 5 figures

\\

In this work, the effects of quantum interference and spontaneously generated

coherence (SGC) are theoretically analyzed in a four level system of a

$^{87}\mathrm{Rb}$ atom. For the effects of SGC, we find that a new kind of EIT

channel can be induced due to destructive interference, and the nonlinear Kerr

absorption can be coherently narrowed or eliminated under different strengths

of the coupling and switching fields.

\\ ( http://arxiv.org/abs/1010.1657 , 619kb)

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arXiv:1010.1671 (*cross-listing*)

Date: Fri, 8 Oct 2010 11:52:06 GMT (69kb)

Title: Engineering of Landau-Zener tunneling

Authors: Ghazal Tayebirad, Riccardo Mannella and Sandro Wimberger

Categories: cond-mat.quant-gas quant-ph

\\

Several ways are discussed how to control the Landau–Zener tunneling in the

Wannier–Stark system. We focus on a realization of this system with interacting

and noninteracting ultracold bosons. The tunneling from the ground band to the

continuum is shown to depend crucially on the initial condition and system

parameters and, more interestingly, on added timedependent disorder – noise –

on the lattice beams.

\\ ( http://arxiv.org/abs/1010.1671 , 69kb)

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arXiv:1010.1716 (*cross-listing*)

Date: Fri, 8 Oct 2010 15:34:35 GMT (25kb)

Title: Dirac Equation For Cold Atoms In Artificial Curved Spacetimes

Authors: O. Boada, A. Celi, J. I. Latorre and M. Lewenstein

Categories: cond-mat.quant-gas cond-mat.str-el hep-th quant-ph

Comments: 12 pages

\\

We argue that the Fermi-Hubbard Hamiltonian describing the physics of

ultracold atoms on optical lattices in the presence of artificial non-Abelian

gauge fields, is exactly equivalent to the gauge theory Hamiltonian describing

Dirac fermions in the lattice. We show that it is possible to couple the Dirac

fermions to an "artificial" gravitational field, i.e. to consider the Dirac

physics in a curved spacetime. We identify the special class of spacetime

metrics that admit a simple realization in terms of a Fermi-Hubbard model

subjected to an artificial $SU(2)$ field, corresponding to position dependent

hopping matrices. As an example, we discuss in more detail the physics of 2+1D

Rindler metric, its possible experimental realization and detection.

\\ ( http://arxiv.org/abs/1010.1716 , 25kb)

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arXiv:1010.1730

Date: Fri, 8 Oct 2010 16:24:22 GMT (818kb)

Title: Simulating quantum-optical phenomena with cold atoms in optical lattices

Authors: Carlos Navarrete-Benlloch, In\'es de Vega, Diego Porras, and J.

Ignacio Cirac

Categories: quant-ph

\\

We propose a scheme involving cold atoms trapped in optical lattices to

observe different phenomena traditionally linked to quantum-optical systems.

The basic idea consists of connecting the trapped atomic state to a non-trapped

state through a Raman scheme. The coupling between these two types of atoms

(trapped and free) turns out to be similar to that describing light-matter

interaction within the rotating-wave approximation, the role of matter and

photons being played by the trapped and free atoms, respectively. We explain in

particular how to observe phenomena arising from the collective spontaneous

emission of atomic and harmonic oscillator samples such as superradiance and

directional emission. We also show how the same setup can simulate Bose-Hubbard

Hamiltonians with extended hopping as well as Ising models with long-range

interactions. We believe that this system can be realized with state of the art

technology.

\\ ( http://arxiv.org/abs/1010.1730 , 818kb)

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arXiv:1010.1744 (*cross-listing*)

Date: Fri, 8 Oct 2010 17:27:53 GMT (943kb,D)

Title: Analytical solution to position dependent mass Schr\"odinger equation

Authors: Pankaj K. Jha, Hichem Eleuch and Yuri V. Rostovtsev

Categories: cond-mat.other physics.atom-ph quant-ph

Comments: 5 pages, 4 figures

\\

Using a recently developed technique to solve Schr\"odinger equation for

constant mass, we studied the regime in which mass varies with position i.e

position dependent mass Schr\"odinger equation(PDMSE). We obtained an

analytical solution for the PDMSE and applied our approach to study a position

dependent mass $m(x)$ particle scattered by a potential $\mathcal{V}(x)$. We

also studied the structural analogy between PDMSE and two-level atomic system

interacting with a classical field.

\\ ( http://arxiv.org/abs/1010.1744 , 943kb)

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arXiv:1010.1776

Date: Fri, 8 Oct 2010 20:00:08 GMT (558kb)

Title: Collapse and revival oscillations as a probe for the tunneling amplitude

in an ultra-cold Bose gas

Authors: F. Alexander Wolf, Itay Hen, and Marcos Rigol

Categories: cond-mat.quant-gas

Comments: 10 pages, 12 figures

Journal-ref: Phys. Rev. A 82, 043601 (2010)

DOI: 10.1103/PhysRevA.82.043601

\\

We present a theoretical study of the quantum corrections to the revival time

due to finite tunneling in the collapse and revival of matter wave interference

after a quantum quench. We study hard-core bosons in a superlattice potential

and the Bose-Hubbard model by means of exact numerical approaches and

mean-field theory. We consider systems without and with a trapping potential

present. We show that the quantum corrections to the revival time can be used

to accurately determine the value of the hopping parameter in experiments with

ultracold bosons in optical lattices.

\\ ( http://arxiv.org/abs/1010.1776 , 558kb)

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arXiv:1010.1778

Date: Fri, 8 Oct 2010 20:34:04 GMT (205kb)

Title: Suppression of Faraday waves in a Bose-Einstein condensate in the

presence of an optical lattice

Authors: Pablo Capuzzi, Mario Gattobigio, and Patrizia Vignolo

Categories: cond-mat.quant-gas

\\

We study the formation of Faraday waves in an elongated Bose-Einstein

condensate in presence of a one-dimensional optical lattice, where phonons are

parametrically excited by modulating the radial confinement of the condensate.

For very shallow optical lattices, phonons with a well-defined wave vector

propagate along the condensate, as in the absence of the lattice, and we

observe the formation of a Faraday pattern. By increasing the potential depth,

the local sound velocity decreases and when it equals the condensate local

phase velocity, the condensate becomes dynamically unstable and the parametric

excitation of Faraday waves is suppressed.

\\ ( http://arxiv.org/abs/1010.1778 , 205kb)

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arXiv:1010.1782

Date: Fri, 8 Oct 2010 21:02:10 GMT (414kb)

Title: Tunable exciton-phonon interactions in an optical lattice of polar

molecules

Authors: Felipe Herrera and Roman V. Krems

Categories: physics.atom-ph physics.chem-ph quant-ph

Comments: 5 pages, 5 figures

\\

We show that an ensemble of polar molecules trapped in an optical lattice can

be considered as a controllable open quantum system. The coupling between

collective rotational excitations and the center-of-mass vibrations of the

molecules in the lattice potential can be controlled by varying the strength

and orientation of an external dc electric field, as well as the intensity of

the trapping laser. The system can be described by a generalized Holstein

Hamiltonian with tunable parameters. As an example, we consider an ensemble of

LiCs molecules to show that the electric field can modify the character of

rotational excitation energy transfer.

\\ ( http://arxiv.org/abs/1010.1782 , 414kb)

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arXiv:1010.1808

Date: Sat, 9 Oct 2010 03:41:40 GMT (391kb)

Title: Landau-Ginzburg Perspective of Finite-Temperature Phase Diagrams of a

Two-Component Fermi-Bose Mixture

Authors: Michael Fodor and Hong Y. Ling

Categories: cond-mat.quant-gas

Comments: To appear in Physical Review A

\\

We consider a mixture of two-component Fermi and (one-component) bose gases

under the repulsive Bose-Fermi and attractive Fermi-Fermi interaction. We

perform a systematic study of the finite-temperature phase diagrams in the

chemical potential space, identifying, using the Landau-Ginzburg theory, the

features generic to the phase diagrams within the validity of our model. We

apply the theory to explore the physics of correlated BCS pairing among

fermions in a tightly confined trap surrounded by a large BEC gas.

\\ ( http://arxiv.org/abs/1010.1808 , 391kb)

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arXiv:1010.1816

Date: Sat, 9 Oct 2010 06:41:24 GMT (1267kb)

Title: Dynamic Many-Body Theory. II. Dynamics of Strongly Correlated Fermi

Fluids

Authors: H. M. B\"ohm, R. Holler, E. Krotscheck, M. Panholzer

Categories: cond-mat.other

Comments: submitted to Phys. Rev. B

\\

We develop a systematic theory of multi-particle excitations in strongly

interacting Fermi systems. Our work is the generalization of the time-honored

work by Jackson, Feenberg, and Campbell for bosons, that provides, in its most

advanced implementation, quantitative predictions for the dynamic structure

function in the whole experimentally accessible energy/momentum regime. Our

view is that the same physical effects -- namely fluctuations of the wave

function at an atomic length scale -- are responsible for the correct

energetics of the excitations in both Bose and Fermi fluids. Besides a

comprehensive derivation of the fermion version of the theory and discussion of

the approximations made, we present results for homogeneous He-3 and electrons

in three dimensions. We find indeed a significant lowering of the zero sound

mode in He-3 and a broadening of the collective mode due to the coupling to

particle-hole excitations in good agreement with experiments. The most visible

effect in electronic systems is the appearance of a ``double-plasmon''

excitation.

\\ ( http://arxiv.org/abs/1010.1816 , 1267kb)

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arXiv:1010.1874 (*cross-listing*)

Date: Sat, 9 Oct 2010 21:32:04 GMT (507kb,D)

Title: Speckle Imaging of Spin Fluctuations in a Strongly Interacting Fermi Gas

Authors: Christian Sanner, Edward J. Su, Aviv Keshet, Wujie Huang, Jonathon

Gillen, Ralf Gommers, and Wolfgang Ketterle

Categories: cond-mat.quant-gas physics.atom-ph

\\

Spin fluctuations and density fluctuations are studied for a two-component

gas of strongly interacting fermions along the BEC-BCS crossover. This is done

by in-situ imaging of dispersive speckle patterns. Compressibility and magnetic

susceptibility are determined from the measured fluctuations. This new

sensitive method easily resolves a tenfold suppression of spin fluctuations

below shot noise due to pairing, and can be applied to novel magnetic phases in

optical lattices.

\\ ( http://arxiv.org/abs/1010.1874 , 507kb)

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arXiv:1010.1954

Date: Sun, 10 Oct 2010 18:52:10 GMT (113kb)

Title: Measurement of an Efimov trimer binding energy in a three-component

mixture of 6Li

Authors: Shuta Nakajima, Munekazu Horikoshi, Takashi Mukaiyama, Pascal Naidon,

and Masahito Ueda

Categories: cond-mat.quant-gas

Comments: 4 pages, 4 figures

\\

The binding energy of an Efimov trimer state was precisely determined via

radio-frequency association. It is found that the measurement results

significantly shift with temperature, but that the shift can be made negligible

at the lowest temperature in our experiment. The obtained trimer binding energy

reveals a significant deviation from the nonuniversal theory prediction based

on a three-body parameter with a monotonic energy dependence.

\\ ( http://arxiv.org/abs/1010.1954 , 113kb)

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arXiv:1010.2033

Date: Mon, 11 Oct 2010 08:14:17 GMT (2534kb)

Title: Precision measurement of gravity with cold atoms in an optical lattice

and comparison with a classical gravimeter

Authors: N. Poli, F.-Y. Wang, M. G. Tarallo, A. Alberti, M. Prevedelli, G. M.

Tino

Categories: physics.atom-ph

Comments: 4 pages, 4 figures

\\

We report on a high precision measurement of gravitational acceleration using

ultracold strontium atoms trapped in a vertical optical lattice. Using

amplitude modulation of the lattice intensity, an uncertainty $\Delta g /g

\approx 10^{-7}$ was reached by measuring at the 5$^{th}$ harmonic of the Bloch

oscillation frequency. After a careful analysis of systematic effects, the

value obtained with this microscopic quantum system is consistent with the one

we measured with a classical absolute gravimeter at the same location. This

result is of relevance for the recent interpretation of related experiments as

tests of gravitational redshift and opens the way to new tests of gravity at

micrometer scale.

\\ ( http://arxiv.org/abs/1010.2033 , 2534kb)

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arXiv:1010.2092

Date: Mon, 11 Oct 2010 13:01:53 GMT (266kb,D)

Title: Inelastic chaotic scattering on a Bose-Einstein condensate

Authors: Stefan Hunn, Moritz Hiller, Andreas Buchleitner, Doron Cohen,

Tsampikos Kottos

Categories: quant-ph cond-mat.quant-gas

Comments: 4 pages, 4 figures

\\

We devise a microscopic scattering approach to probe the excitation spectrum

of a Bose-Einstein condensate. We show that the experimentally accessible

scattering cross section exhibits universal Ericson fluctuations, with

characteristic properties rooted in the underlying classical field equations.

\\ ( http://arxiv.org/abs/1010.2092 , 266kb)

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arXiv:1010.2100 (*cross-listing*)

Date: Mon, 11 Oct 2010 13:35:40 GMT (408kb)

Title: Development of instability of dark solitons generated by a flow of

Bose-Einstein condensate past a concave corner

Authors: A. M. Kamchatnov and S. V. Korneev

Categories: nlin.PS cond-mat.quant-gas

Comments: 4 pages, 2 figures, 1 table

\\

The stability of dark solitons generated by a supersonic flow of a

Bose-Einstein condensate past a concave corner (or a wedge) is studied. It is

shown that solitons in the dispersive shock wave generated at the initial

moment of time demonstrate a snake instability during their evolution to

stationary curved solitons. Time of decay of soliton to vortices agrees very

well with analytical estimates of the instability growth rate.

\\ ( http://arxiv.org/abs/1010.2100 , 408kb)

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arXiv:1010.2123

Date: Mon, 11 Oct 2010 14:51:57 GMT (410kb)

Title: Cascade coherence transfer and magneto-optical resonances at 455 nm

excitation of Cesium

Authors: Marcis Auzinsh, Ruvin Ferber, Florian Gahbauer, Andrey Jarmola,

Linards Kalvans, and Aigars Atvars

Categories: physics.atom-ph

Comments: 12 pages, 8 figures

\\

We present and experimental and theoretical study of nonlinear

magneto-optical resonances observed in the fluorescence to the ground state

from the 7P_{3/2} state of cesium, which was populated directly by laser

radiation at 455 nm, and from the 6P_{1/2} and 6P_{3/2} states, which were

populated via cascade transitions that started from the 7P_{3/2} state and

passed through various intermediate states. The laser-induced fluorescence

(LIF) was observed as the magnetic field was scanned through zero. Signals were

recorded for the two orthogonal, linearly polarized components of the LIF. We

compared the measured signals with the results of calculations from a model

that was based on the optical Bloch equations and averaged over the Doppler

profile. This model was adapted from a model that had been developed for D_1

and D_2 excitation of alkali metal atoms. The calculations agree quite well

with the measurements, especially when taking into account the fact that some

experimental parameters were only estimated in the model.

\\ ( http://arxiv.org/abs/1010.2123 , 410kb)

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arXiv:1010.2205

Date: Mon, 11 Oct 2010 20:00:02 GMT (758kb,D)

Title: Detecting the Amplitude Mode of Strongly Interacting Lattice Bosons by

Bragg Scattering

Authors: U. Bissbort, Y. Li, S. G\"otze, J. Heinze, J. S. Krauser, M. Weinberg,

C. Becker, K. Sengstock, W. Hofstetter

Categories: cond-mat.quant-gas

Comments: 4 pages, 3 figures

\\

We report the first detection of the Higgs-type amplitude mode using Bragg

spectroscopy in a strongly interacting condensate of ultracold atoms in an

optical lattice. By the comparison of our experimental data with a spatially

resolved, time-dependent dynamic Gutzwiller calculation, we obtain good

quantitative agreement. This allows for a clear identification of the amplitude

mode, showing that it can be detected with full momentum resolution by going

beyond the linear response regime. A systematic shift of the sound and

amplitude modes' resonance frequencies due to the finite Bragg beam intensity

is observed.

\\ ( http://arxiv.org/abs/1010.2205 , 758kb)

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arXiv:1010.2254

Date: Mon, 11 Oct 2010 22:26:30 GMT (3029kb)

Title: Solitons in nonlinear lattices

Authors: Yaroslav V. Kartashov, Boris A. Malomed, Lluis Torner

Categories: physics.optics

Comments: 169 pages, 35 figures, a comprehensive survey of results on solitons

in purely nonlinear and mixed lattices, to appear in Reviews of Modern

Physics

\\

This article offers a comprehensive survey of results obtained for solitons

and complex nonlinear wave patterns supported by purely nonlinear lattices

(NLs), which represent a spatially periodic modulation of the local strength

and sign of the nonlinearity, and their combinations with linear lattices. A

majority of the results obtained, thus far, in this field and reviewed in this

article are theoretical. Nevertheless, relevant experimental settings are

surveyed too, with emphasis on perspectives for implementation of the

theoretical predictions in the experiment. Physical systems discussed in the

review belong to the realms of nonlinear optics (including artificial optical

media, such as photonic crystals, and plasmonics) and Bose-Einstein

condensation (BEC). The solitons are considered in one, two, and three

dimensions (1D, 2D, and 3D). Basic properties of the solitons presented in the

review are their existence, stability, and mobility. Although the field is

still far from completion, general conclusions can be drawn. In particular, a

novel fundamental property of 1D solitons, which does not occur in the absence

of NLs, is a finite threshold value of the soliton norm, necessary for their

existence. In multidimensional settings, the stability of solitons supported by

the spatial modulation of the nonlinearity is a truly challenging problem, for

the theoretical and experimental studies alike. In both the 1D and 2D cases,

the mechanism which creates solitons in NLs is principally different from its

counterpart in linear lattices, as the solitons are created directly, rather

than bifurcating from Bloch modes of linear lattices.

\\ ( http://arxiv.org/abs/1010.2254 , 3029kb)

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arXiv:1010.2268

Date: Tue, 12 Oct 2010 00:20:39 GMT (592kb)

Title: Exact asymptotes of static and dynamic correlation functions of the 1D

Bose gas

Authors: Aditya Shashi, Leonid I. Glazman, Jean-Sebastien Caux and Adilet

Imambekov

Categories: cond-mat.stat-mech

Comments: 45 pages (including supplementary material), 4 figures and 1 table

\\

We consider correlation functions of the integrable Lieb-Liniger 1D Bose gas.

By combining field theoretical approaches with finite size scaling of the exact

form factors, we analytically obtain the "non-universal" prefactors of the

long-distance behavior of correlation functions. We also evaluate prefactors of

singularities in dynamic response functions such as the density structure

factor and spectral function, and prove the existence of singularities within a

continuum spectrum.

\\ ( http://arxiv.org/abs/1010.2268 , 592kb)

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arXiv:1010.2413

Date: Tue, 12 Oct 2010 15:19:39 GMT (23kb)

Title: Observation of St\"{u}ckelberg oscillations in accelerated optical

lattices

Authors: A. Zenesini and D. Ciampini and O. Morsch and E. Arimondo

Categories: cond-mat.quant-gas

Comments: 4 pages, 4 figures

\\

We report the experimental observation of St\"{u}ckelberg oscillations of

matter waves in optical lattices. Extending previous work on Landau-Zener

tunneling of Bose-Einstein condensates in optical lattices, we study the

effects of the accumulated phase between two successive crossings of the

Brillouin zone edge. Our results agree well with a simple model for multiple

Landau-Zener tunneling events taking into account the band structure of the

optical lattice.

\\ ( http://arxiv.org/abs/1010.2413 , 23kb)

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arXiv:1010.2415 (*cross-listing*)

Date: Tue, 12 Oct 2010 15:23:11 GMT (87kb)

Title: Seniority in quantum many-body systems

Authors: P. Van Isacker (GANIL)

Categories: nucl-th cond-mat.quant-gas physics.atom-ph

Comments: 16 pages, 1 figure, accepted for publication in the Proceedings of

The American Institute of Physics

Report-no: GANIL P 2010-015

\\

The use of the seniority quantum number in many-body systems is reviewed. A

brief summary is given of its introduction by Racah in the context of atomic

spectroscopy. Several extensions of Racah's original idea are discussed:

seniority for identical nucleons in a single-$j$ shell, its extension to the

case of many, non-degenerate $j$ shells and to systems with neutrons and

protons. To illustrate its usefulness to this day, a recent application of

seniority is presented in Bose--Einstein condensates of atoms with spin.

\\ ( http://arxiv.org/abs/1010.2415 , 87kb)

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arXiv:1010.2504 (*cross-listing*)

Date: Tue, 12 Oct 2010 20:12:53 GMT (9kb)

Title: Soliton-like Solutions for Nonlinear Schroedinger Equation with variable

quadratic Hamiltonians

Authors: Erwin Suazo and Sergei K. Suslov

Categories: math-ph math.MP quant-ph

Comments: 6 pages, no figures

\\

We construct soliton-like solutions for the nonlinear Schroedinger equation

with variable quadratic Hamiltonians

\\ ( http://arxiv.org/abs/1010.2504 , 9kb)

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arXiv:1010.2514

Date: Tue, 12 Oct 2010 20:45:38 GMT (424kb)

Title: Quantum walks and quantum simulations with Bloch oscillating spinor

atoms

Authors: D. Witthaut

Categories: quant-ph cond-mat.quant-gas

Comments: published version, 7 figures

Journal-ref: Phys. Rev. A 82, 033602 (2010)

DOI: 10.1103/PhysRevA.82.033602

\\

We propose a scheme for the realization of a quantum walker and a quantum

simulator for the Dirac equation with ultracold spinor atoms in driven optical

lattices. A precise control of the dynamics of the atomic matter wave can be

realized using time-dependent external forces. If the force depends on the spin

state of the atoms, the dynamics will entangle the inner and outer degrees of

freedom which offers unique opportunities for quantum information and quantum

simulation. Here, we introduce a method to realize a quantum walker based on

the state-dependent transport of spinor atoms and a coherent driving of the

internal state. In the limit of weak driving the dynamics is equivalent to that

of a Dirac particle in 1+1 dimensions. Thus it becomes possible to simulate

relativistic effects such as Zitterbewegung and Klein tunneling.

\\ ( http://arxiv.org/abs/1010.2514 , 424kb)

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arXiv:1010.2567

Date: Wed, 13 Oct 2010 03:58:03 GMT (40kb)

Title: Sympathetic cooling of polyatomic molecules with S-state atoms in a

magnetic trap

Authors: T. V. Tscherbul, H-G. Yu, A. Dalgarno

Categories: physics.atom-ph physics.chem-ph

Comments: 5 pages, 3 figures, 1 table

\\

We present a rigorous theoretical study of low-temperature collisions of

polyatomic molecular radicals with ^1S_0 atoms in the presence of an external

magnetic field. Accurate quantum scattering calculations based on ab initio

interaction potentials show that collision-induced spin relaxation of the

prototypical organic molecule CH_2(X^3B_1) (methylene) and 12 other triatomic

radicals in cold 3He gas occurs at a slow rate, demonstrating that cryogenic

buffer-gas cooling and magnetic trapping of these molecules is feasible with

current technology. Our calculations further suggest that it may be possible to

create ultracold gases of polyatomic molecules by sympathetic cooling with

alkaline-earth atoms in a magnetic trap.

\\ ( http://arxiv.org/abs/1010.2567 , 40kb)

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arXiv:1010.2688

Date: Wed, 13 Oct 2010 15:59:16 GMT (30kb)

Title: Mean-field theory for the Mott insulator-paired superfluid transition in

the two-species Bose-Hubbard model

Authors: M. Iskin

Categories: cond-mat.quant-gas

Comments: 3 pages with 2 figures

\\

The standard mean-field theory for the Mott insulator-superfluid phase

transition is not sufficient to describe the Mott insulator-paired superfluid

phase transition. Therefore, by restricting the two-species Bose-Hubbard

Hamiltonian to the subspace of paired particles, and using perturbation theory,

here we derive an analytic mean-field expression for the Mott insulator-paired

superfluid transition boundary.

\\ ( http://arxiv.org/abs/1010.2688 , 30kb)

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arXiv:1010.2813 (*cross-listing*)

Date: Thu, 14 Oct 2010 03:22:28 GMT (744kb,D)

Title: Engineering Biphoton Wave Packets with an Electromagnetically Induced

Grating

Authors: Jianming Wen, Yanhua Zhai, Shengwang Du, and Min Xiao

Categories: quant-ph physics.optics

Comments: Published in Physical Review A 82, 043814 (2010)

DOI: 10.1103/PhysRevA.82.043814

\\

We propose to shape biphoton wave packets with an electromagnetically induced

grating in a four-level double-$\Lambda$ cold atomic system. We show that the

induced hybrid grating plays an essential role in directing the new fields into

different angular positions, especially to the zeroth-order diffraction. A

number of interesting features appear in the shaped two-photon waveforms. For

example, broadening or narrowing the spectrum would be possible in the proposed

scheme even without the use of a cavity.

\\ ( http://arxiv.org/abs/1010.2813 , 744kb)

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arXiv:1010.2854

Date: Thu, 14 Oct 2010 08:24:53 GMT (24kb)

Title: Tuning the non-linearity of a low-dimensional Bose-Einstein condensate

exploiting the self-similar transverse dynamics

Authors: A. del Campo

Categories: cond-mat.quant-gas

Comments: 5 pages, 2 figures

\\

A method is proposed to tune the amplitude of the non-linearity of a

low-dimensional Bose-Einstein condensate by means of engineering the

time-dependence of the transverse confining potential in a highly anisotropic

trap. The method exploits the existence of integrals of motion leading to a

dynamical self-similar scaling law in the radial degrees of freedom. We discuss

the application of the method to preserve short-range correlations in time of

flight experiments, the implementation of nearly-sudden quenches and its power

to assist self-similar dynamics in quasi-one dimensional condensates.

\\ ( http://arxiv.org/abs/1010.2854 , 24kb)

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arXiv:1010.2864

Date: Thu, 14 Oct 2010 09:35:33 GMT (118kb,D)

Title: Quasi-Nambu-Goldstone Modes in Bose-Einstein Condensates

Authors: Shun Uchino, Michikazu Kobayashi, Muneto Nitta, Masahito Ueda

Categories: cond-mat.quant-gas hep-th nucl-th

Comments: 4 pages, 2 figures

\\

We show that quasi-Nambu-Goldstone (QNG) modes, which play prominent roles in

high energy physics but have been elusive experimentally, can be realized with

atomic Bose-Einstein condensates. The QNG modes emerge when the symmetry of a

ground state is larger than that of the Hamiltonian. When they appear, the

conventional order parameter manifold (OPM) should be enlarged. Consequently

topological defects that are stable within the conventional OPM become unstable

and decay by emitting the QNG modes. Contrary to conventional wisdom, however,

we show that the topological defects are stabilized by quantum fluctuations

that make the QNG modes massive, thereby suppressing their emission.

\\ ( http://arxiv.org/abs/1010.2864 , 118kb)

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arXiv:1010.2890

Date: Thu, 14 Oct 2010 12:40:55 GMT (586kb)

Title: Functional renormalization for the BCS-BEC crossover

Authors: Michael M. Scherer, Stefan Floerchinger, Holger Gies

Categories: cond-mat.quant-gas

Comments: 18 pages, 6 figures, 2 tables, invited review for a Theme Issue of

the Phil. Trans. A on new developments of the functional RG

\\

We review the functional renormalization group (RG) approach to the BCS-BEC

crossover for an ultracold gas of fermionic atoms. Formulated in terms of a

scale-dependent effective action, the functional RG interpolates continuously

between the atomic or molecular microphysics and the macroscopic physics on

large length scales. We concentrate on the discussion of the phase diagram as a

function of the scattering length and the temperature which is a paradigm

example for the non-perturbative power of the functional RG. A systematic

derivative expansion provides for both a description of the many-body physics

and its expected universal features as well as an accurate account of the

few-body physics and the associated BEC and BCS limits.

\\ ( http://arxiv.org/abs/1010.2890 , 586kb)

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arXiv:1010.2965 (*cross-listing*)

Date: Thu, 14 Oct 2010 16:16:12 GMT (7kb)

Title: Gravity-analogy in one-dimensional ideal Fermi fluids and Burgers'

equation

Authors: Stefano Giovanazzi

Categories: cond-mat.other quant-ph

Comments: 4 pages

\\

An hydrodynamic description of a one-dimensional flow of an ideal Fermi fluid

is constructed from a semiclassical approximation. For an initially fully

degenerate fluid, Euler and continuity hydrodynamic equations are dual to two

uncoupled inviscid Burgers' equations. Yet the price for the initial simplicity

of the description is paid by the complexity of non-linear instabilities

towards possible turbulent evolutions. Nevertheless, it is shown that linear

long-wavelength density perturbations on a stationary flow are generically

stable. Consequently, linear sound obeys a wave equation with analogy to

gravity. The results have applications for ultra-cold atomic gases.

\\ ( http://arxiv.org/abs/1010.2965 , 7kb)

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The replacements:

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arXiv:1006.4429

replaced with revised version Fri, 8 Oct 2010 11:29:01 GMT (743kb)

Title: Quantitative study of two- and three-dimensional strong localization of

matter waves by atomic scatterers

Authors: Mauro Antezza (LKB - Lhomond), Yvan Castin (LKB - Lhomond), David

Hutchinson

Categories: cond-mat.quant-gas

Journal-ref: Physical Review A 82 (2010) 043602

\\ ( http://arxiv.org/abs/1006.4429 , 743kb)

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arXiv:1001.0021

replaced with revised version Fri, 8 Oct 2010 12:45:11 GMT (48kb)

Title: Strong-coupling expansion for the two-species Bose-Hubbard model

Authors: M. Iskin

Categories: cond-mat.quant-gas cond-mat.str-el

Comments: 8 pages, 4 figures, and 2 tables (published version)

Journal-ref: Phys. Rev. A 82, 033630 (2010) [8 pages]

\\ ( http://arxiv.org/abs/1001.0021 , 48kb)

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arXiv:1004.3111

replaced with revised version Fri, 8 Oct 2010 13:26:02 GMT (534kb)

Title: Cooper pairing and BCS-BEC evolution in mixed-dimensional Fermi gases

Authors: M. Iskin and A. L. Subasi

Categories: cond-mat.quant-gas cond-mat.supr-con

Comments: 8 pages with 4 figures

\\ ( http://arxiv.org/abs/1004.3111 , 534kb)

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arXiv:1005.1399

replaced with revised version Fri, 8 Oct 2010 17:53:33 GMT (34kb)

Title: Simulating Wess-Zumino Supersymmetry Model in Optical Lattices

Authors: Yue Yu and Kun Yang

Categories: cond-mat.quant-gas hep-th

Comments: 4 pages, 1 figure, published verison in PRL with slight difference

Journal-ref: Phys. Rev. Lett. 105, 150605 (2010)

DOI: 10.1103/PhysRevLett.105.150605

\\ ( http://arxiv.org/abs/1005.1399 , 34kb)

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arXiv:1007.4939 (*cross-listing*)

replaced with revised version Fri, 8 Oct 2010 18:52:26 GMT (100kb)

Title: Isotropic Contact Forces in Arbitrary Representation: Heterogeneous

Few-Body Problems and Low Dimensions

Authors: Ludovic Pricoupenko (LPTMC)

Categories: cond-mat.quant-gas quant-ph

\\ ( http://arxiv.org/abs/1007.4939 , 100kb)

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arXiv:1010.0806

replaced with revised version Sat, 9 Oct 2010 08:58:32 GMT (672kb)

Title: Equilibrium and off-equilibrium trap-size scaling in 1D ultracold

bosonic gases

Authors: Massimo Campostrini and Ettore Vicari

Categories: cond-mat.quant-gas cond-mat.stat-mech

Comments: 24 pages, 36 figs, few changes, refs added

\\ ( http://arxiv.org/abs/1010.0806 , 672kb)

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arXiv:1006.0453

replaced with revised version Mon, 11 Oct 2010 08:10:28 GMT (51kb)

Title: Non-abelian anyons from degenerate Landau levels of ultracold atoms in

artificial gauge potentials

Authors: Michele Burrello and Andrea Trombettoni

Categories: cond-mat.quant-gas

Comments: Published version

Journal-ref: Phys. Rev. Lett. 105, 125304 (2010)

\\ ( http://arxiv.org/abs/1006.0453 , 51kb)

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arXiv:0911.0655

replaced with revised version Mon, 11 Oct 2010 09:00:57 GMT (1089kb)

Title: Noise in Bose Josephson junctions: Decoherence and phase relaxation

Authors: G. Ferrini, D. Spehner, A. Minguzzi, F.W.J. Hekking

Categories: quant-ph cond-mat.quant-gas

Comments: Fig 2 added; version accepted for publication

Journal-ref: PRA 82, 033621 (2010)

\\ ( http://arxiv.org/abs/0911.0655 , 1089kb)

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arXiv:1003.0649 (*cross-listing*)

replaced with revised version Tue, 12 Oct 2010 07:30:48 GMT (12kb)

Title: Entanglement and sensitivity in precision measurements with states of a

fluctuating number of particles

Authors: P. Hyllus, L. Pezz\'e and A. Smerzi

Categories: quant-ph cond-mat.quant-gas

Comments: Published version

Journal-ref: Phys. Rev. Lett. 105, 120501 (2010)

\\ ( http://arxiv.org/abs/1003.0649 , 12kb)

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arXiv:1008.0007

replaced with revised version Tue, 12 Oct 2010 10:23:32 GMT (75kb)

Title: Viscosity and scale invariance in the unitary Fermi gas

Authors: Tilman Enss, Rudolf Haussmann, Wilhelm Zwerger

Categories: cond-mat.quant-gas hep-th quant-ph

Comments: 34 pages, 9 figures; final form (contains new derivation of sum

rule), accepted for publication in Annals of Physics

\\ ( http://arxiv.org/abs/1008.0007 , 75kb)

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arXiv:0907.3814

replaced with revised version Tue, 12 Oct 2010 15:16:40 GMT (706kb)

Title: Superfluid Quenching of the Moment of Inertia in a Strongly Interacting

Fermi Gas

Authors: S. Riedl, E. R. Sanchez Guajardo, C. Kohstall, J. Hecker Denschlag, R.

Grimm

Categories: cond-mat.quant-gas

Comments: 9 pages, revised discussion of experimental results, new figure 3

\\ ( http://arxiv.org/abs/0907.3814 , 706kb)

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arXiv:1008.2964

replaced with revised version Tue, 12 Oct 2010 18:00:00 GMT (16kb)

Title: High temperature correlation functions: universality, extraction of pair

interactions, divergent correlation lengths, and dimensional reductions

Authors: Saurish Chakrabarty and Zohar Nussinov

Categories: cond-mat.stat-mech hep-th physics.data-an

Comments: 8 pages (4 main text + 4 supplementary information)

\\ ( http://arxiv.org/abs/1008.2964 , 16kb)

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arXiv:1010.1200

replaced with revised version Tue, 12 Oct 2010 20:28:53 GMT (53kb)

Title: Bethe-Salpeter equations for the collective-mode spectrum of a

superfluid Fermi gas in a moving optical lattice

Authors: Zlatko Koinov

Categories: cond-mat.str-el

\\ ( http://arxiv.org/abs/1010.1200 , 53kb)

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arXiv:1008.1457

replaced with revised version Wed, 13 Oct 2010 00:50:59 GMT (260kb)

Title: Virial expansion for a strongly correlated Fermi gas with imbalanced

spin populations

Authors: Xia-Ji Liu and Hui Hu

Categories: cond-mat.quant-gas

Comments: 7 pages, 5 figures, accepted in Phys. Rev. A

\\ ( http://arxiv.org/abs/1008.1457 , 260kb)

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arXiv:0901.1726

replaced with revised version Wed, 13 Oct 2010 05:49:43 GMT (0kb,I)

Title: Quantum metrology to probe atomic parity violation

Authors: M. Mukherjee

Categories: quant-ph

Comments: This paper has been withdrawn by the author due to major changes made

in the paper

\\ ( http://arxiv.org/abs/0901.1726 , 0kb)

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arXiv:1006.4734

replaced with revised version Wed, 13 Oct 2010 09:58:22 GMT (2182kb)

Title: Groundstate and Collective Modes of a Spin-Polarized Dipolar

Bose-Einstein Condensate in a Harmonic Trap

Authors: I. Sapina, T. Dahm and N. Schopohl

Categories: cond-mat.quant-gas cond-mat.other

Comments: Final version, accepted for publication in Physical Review A

\\ ( http://arxiv.org/abs/1006.4734 , 2182kb)

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arXiv:1007.4045

replaced with revised version Wed, 13 Oct 2010 11:41:23 GMT (1335kb)

Title: Vortex core transitions in superfluid 3He in globally anisotropic

aerogels

Authors: Kazushi Aoyama and Ryusuke Ikeda

Categories: cond-mat.supr-con

Comments: 7 pages, 6 figures Text was changed. Resubmitted version

\\ ( http://arxiv.org/abs/1007.4045 , 1335kb)

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arXiv:quant-ph/0109130

replaced with revised version Wed, 13 Oct 2010 20:04:58 GMT (0kb,I)

Title: Coherent Decays of Atoms

Authors: Yakir Aharonov, Jeeva Anandan and Shmuel Nussinov

Categories: quant-ph

Comments: This paper has been withdrawn by the authors. 8 pages

\\ ( http://arxiv.org/abs/quant-ph/0109130 , 0kb)

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arXiv:1010.1268

replaced with revised version Wed, 13 Oct 2010 20:37:14 GMT (636kb)

Title: Projective approach to the entanglement entropy of 1-$d$ fermions

Authors: G. C. Levine and B. A. Friedman

Categories: cond-mat.stat-mech

Comments: 8 pages, 6 figures; fixed typos

\\ ( http://arxiv.org/abs/1010.1268 , 636kb)

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arXiv:1009.4114

replaced with revised version Wed, 13 Oct 2010 20:56:44 GMT (8kb)

Title: On the Bose-Einstein Condensation of Rotons

Authors: Lev A. Melnikovsky

Categories: cond-mat.other cond-mat.quant-gas

Comments: 9 pages, number decay exponet corrected, references added, minor

fixes

\\ ( http://arxiv.org/abs/1009.4114 , 8kb)

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arXiv:1007.3245

replaced with revised version Thu, 14 Oct 2010 14:02:34 GMT (1008kb,D)

Title: Anisotropic sub-Doppler laser cooling in dysprosium magneto-optical

traps

Authors: Seo Ho Youn, Mingwu Lu, and Benjamin L. Lev

Categories: physics.atom-ph quant-ph

Comments: 4 pages, 5 figures

Journal-ref: PRA 82, 043403 (2010)

DOI: 10.1103/PhysRevA.82.043403

\\ ( http://arxiv.org/abs/1007.3245 , 1008kb)

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arXiv:1009.2075

replaced with revised version Thu, 14 Oct 2010 14:39:05 GMT (349kb)

Title: Hyperfine, rotational, and vibrational structure of the triplet ground

state of Rb molecules

Authors: Christoph Strauss, Tetsu Takekoshi, Florian Lang, Klaus Winkler,

Rudolf Grimm, Johannes Hecker Denschlag, and Eberhard Tiemann

Categories: physics.atom-ph cond-mat.other

\\ ( http://arxiv.org/abs/1009.2075 , 349kb)

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arXiv:1002.0195

replaced with revised version Thu, 14 Oct 2010 15:52:35 GMT (131kb,D)

Title: First and second sound in cylindrically trapped gases

Authors: G. Bertaina, L. Pitaevskii, S. Stringari

Categories: cond-mat.quant-gas physics.flu-dyn

Comments: 4 pages, 2 figures. Published version in Phys. Rev. Lett

Journal-ref: Phys. Rev. Lett. 105, 150402 (2010)

DOI: 10.1103/PhysRevLett.105.150402

\\ ( http://arxiv.org/abs/1002.0195 , 131kb)

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Till next time,

Matt.

-- ========================================================================= Dr M. J. Davis, Associate Professor in Physics School of Mathematics and Physics, ph : +61 7 334 69824 The University of Queensland, fax : +61 7 336 51242 Brisbane, QLD 4072, mdavis_at_physics.uq.edu.au Australia. www.physics.uq.edu.au/people/mdavis/ ========================================================================= 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 ========================================================================= _______________________________________________ Matts-arxiv mailing list Matts-arxiv_at_lists.sps.uq.edu.auReceived on Thu Nov 11 2010 - 17:36:56 EST

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