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

Date: Thu, 25 Sep 2008 10:16:08 +1000

Date: Thu, 25 Sep 2008 10:16:08 +1000

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

This week saw 26 new preprints and 11 replacements:

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arXiv:0808.4077

Date: Fri, 29 Aug 2008 11:37:05 GMT (112kb)

Title: Association of ultracold double-species bosonic molecules

Authors: C. Weber, G. Barontini, J. Catani, G. Thalhammer, M. Inguscio, and F.

Minardi

Categories: cond-mat.other

Comments: 5 pages, 4 figures

\\

We report on the creation of heterospecies bosonic molecules, associated from

an ultracold Bose-Bose mixture of 41K and 87Rb, by using a resonantly modulated

magnetic field close to two Feshbach resonances. We measure the binding energy

of the weakly bound molecular states versus the Feshbach field and compare our

results to theoretical predictions. We observe the broadening and asymmetry of

the association spectrum due to thermal distribution of the atoms, and a

frequency shift occurring when the binding energy depends nonlinearly on the

Feshbach field. A simple model is developed to quantitatively describe the

association process. Our work marks an important step forward in the

experimental route towards Bose-Einstein condensates of dipolar molecules.

\\ ( http://arxiv.org/abs/0808.4077 , 112kb)

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arXiv:0808.4137

Date: Fri, 29 Aug 2008 17:27:03 GMT (49kb)

Title: Effect of Induced Spin-Orbit Coupling for Atoms via Laser Fields

Authors: Xiong-Jun Liu, Mario F. Borunda, Xin Liu and Jairo Sinova

Categories: cond-mat.stat-mech cond-mat.mes-hall

Comments: 4 pages, 3 figures

\\

We propose an experimental scheme to study spin-orbit coupling effects in a

of two-dimensional (2D) Fermi atomic gas cloud by coupling its internal

electronic states (pseudospins) to radiation in a delta configuration. The

induced spin-orbit coupling can be of the Dresselhaus and Rashba type with and

without a Zeeman term. We show that the optically induced spin-orbit coupling

can lead to a spin-dependent effective mass under appropriate condition, with

one of them able to be tuned between positive and negative effective mass. As a

direct observable we show that in the expansion dynamics of the atomic cloud

the initial atomic cloud splits into two clouds for the positive effective mass

case regime, and into four clouds for the negative effective mass regime.

\\ ( http://arxiv.org/abs/0808.4137 , 49kb)

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arXiv:0808.4147

Date: Fri, 29 Aug 2008 18:29:33 GMT (731kb,D)

Title: Heteronuclear quantum gas mixtures

Authors: C. Ospelkaus, S. Ospelkaus

Categories: cond-mat.other cond-mat.stat-mech

Comments: 72 pages, accepted for publication in J. Phys. B: At. Mol. Opt. Phys.

as a PhD tutorial article

\\

This PhD tutorial article is a review of our experiments on heteronuclear

quantum gas mixtures at the University of Hamburg. We introduce basic

properties of trapped Fermi-Bose mixtures and demonstrate the achievement of

large quantum degenerate mixtures of 40K and 87Rb. Using heteronuclear Feshbach

resonances, we show how the heteronuclear interaction can be tuned, allowing us

to induce phase separation and collapse for large repulsive and attractive

interactions, respectively. We realize Fermi-Bose mixtures in 3D optical

lattices as a novel quantum many-body system and study coherence properties of

the mixture. Combining our experiments on lattices and Feshbach resonances, we

present the first realization of ultracold heteronuclear Feshbach molecules.

The molecules are created at individual sites of a 3D optical lattice. We

discuss lifetime, binding energy and rf association efficiency in terms of a

universal model and give an outlook for possible future developments.

\\ ( http://arxiv.org/abs/0808.4147 , 731kb)

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arXiv:0808.4143

Date: Fri, 29 Aug 2008 18:07:42 GMT (1976kb,D)

Title: Adiabaticity and localization in one-dimensional incommensurate lattices

Authors: E. E. Edwards, M. Beeler, Tao Hong, and S. L. Rolston

Categories: physics.atom-ph

Comments: 4 pages, 3 figures

\\

We experimentally investigate the role of adiabaticity on localization of a

Bose-Einstein condensate confined in a one-dimensional optical potential

comprised of a shallow primary lattice with additional one or two perturbing

lattice(s) of incommensurate period. We find that even a very weak perturbation

causes dramatic changes in the momentum distribution and makes adiabatic

loading of the combined lattice much more difficult than a single period

lattice. We interpret our results using a band structure model and the

one-dimensional Gross-Pitaevskii equation

\\ ( http://arxiv.org/abs/0808.4143 , 1976kb)

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arXiv:0808.4018 (*cross-listing*)

Date: Fri, 29 Aug 2008 03:56:42 GMT (272kb)

Title: Interference of the evolutions of Rb and Na Bose-Einstein condensates

Authors: Ma Luo, Chengguang Bao, Zhibing Li

Categories: physics.atm-clus physics.comp-ph

Comments: 9 pages, 4 figures

\\

Spin evolution of a mixture of two species of spin-1 Bose-Einstein

condensates (Rb and Na) has been investigated beyond the mean field theory.

Both analytical expression and numerical results on the populations of

spin-components are obtained. The interference is found to depend on the

initial states and the inter-species interaction sensitively. A number of

phenomena arising from the interference have been predicted. In particular,

periodic behavior and the alternate appearances of a zone of oscillation and a

long quiet zone are found.

\\ ( http://arxiv.org/abs/0808.4018 , 272kb)

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arXiv:0809.0038

Date: Sat, 30 Aug 2008 11:40:25 GMT (768kb)

Title: Path integral study of the role of correlation in exchange coupling of

spins in double quantum dots and optical lattices

Authors: Lei Zhang, Matthew Gilbert, Jesper Pedersen, and John Shumway

Categories: cond-mat.str-el

Comments: 5 pages, 6 figures

\\

We explore exchange coupling of a pair of spins in a double dot and in an

optical lattice. Our algorithm uses the frequency of exchanges in a bosonic

path integral, evaluated with Monte Carlo. This algorithm is simple enough to

be a "black box" calculator, yet gives insights into the role of correlation

through two-particle probability densities, visualization of instantons, and

pair correlation functions. We map the problem to Hubbard model and see that

exchange and correlation renormalize the effective parameters, dramatically

lowering U at larger separations.

\\ ( http://arxiv.org/abs/0809.0038 , 768kb)

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arXiv:0809.0040

Date: Sat, 30 Aug 2008 03:54:47 GMT (216kb)

Title: Phase Separation in two-Species Atomic Bose-Einstein Condensate with

Interspecies Feshbach Resonance

Authors: Lu Zhou, Jing Qian, Han Pu, Weiping Zhang, and Hong Y. Ling

Categories: cond-mat.mes-hall cond-mat.other

Comments: 8 pages, 3 figures

\\

We consider a mixture of two-species atomic Bose-Einstein codensates coupled

to a bound molecular state at zero temperature via interspecies Feshbach

resonance. The interspecies Feshbach coupling precludes the possibility of

doubly mixed phases while enables not only the pure molecular superfluid but

also the pure atomic superfluids to exist as distinct phases. We show that this

system is able to support a rich set of phase separations, including that

between two distinct mixed atom-molecule phases. We pay particular attention to

the effects of the Feschbach coupling and the particle collisions on the

miscibility of this multi-component condensate system.

\\ ( http://arxiv.org/abs/0809.0040 , 216kb)

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arXiv:0806.3191 (*cross-listing*)

Date: Thu, 19 Jun 2008 16:42:28 GMT (22kb)

Date (revised v2): Sat, 30 Aug 2008 17:03:32 GMT (22kb)

Title: Energy and Vorticity in Fast Rotating Bose-Einstein Condensates

Authors: M. Correggi, J. Yngvason

Categories: math-ph cond-mat.other math.MP

Comments: 19 pages, LaTeX; typos corrected, clarifying remarks added, some

rearrangements in the text

MSC-class: 35Q55,47J30,76M23

\\

We study a rapidly rotating Bose-Einstein condensate confined to a finite

trap in the framework of two-dimensional Gross-Pitaevskii theory in the strong

coupling (Thomas-Fermi) limit. Denoting the coupling parameter by $1/\eps^2$

and the rotational velocity by $\Omega$, we evaluate exactly the next to

leading order contribution to the ground state energy in the parameter regime

$|\log\eps|\ll \Omega\ll 1/(\eps^2|\log\eps|)$ with $\eps\to 0$. While the TF

energy includes only the contribution of the centrifugal forces the next order

corresponds to a lattice of vortices whose density is proportional to the

rotational velocity.

\\ ( http://arxiv.org/abs/0806.3191 , 22kb)

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arXiv:0809.0061

Date: Sat, 30 Aug 2008 14:02:51 GMT (213kb)

Title: Ultracold Molecules in the Ro-Vibrational Ground State

Authors: F. Lang, K. Winkler, C. Strauss, R. Grimm, J. Hecker Denschlag

Categories: quant-ph

Comments: 17 pages, 6 figures

\\

The successful production of quantum degenerate gases of weakly bound

molecules has triggered a quest for quantum gases of tightly bound molecules.

We report here on the first production of an ultracold gas of tightly bound

Rb_2 molecules in the ro-vibrational ground state, close to quantum degeneracy.

This was achieved by optically transferring weakly bound Rb2 molecules to the

absolute lowest level of the triplet ground state potential with a transfer

efficiency of about 90%. The transfer takes place in a 3D optical lattice which

traps a sizeable fraction of the tightly bound molecules with a lifetime

exceeding 200 ms. These results open the door for experiments with tightly

bound ultracold molecules, investigations of ultracold collisions and

chemistry, production of a molecular Bose-Einstein condensate (BEC), and

molecular quantum optics.

\\ ( http://arxiv.org/abs/0809.0061 , 213kb)

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arXiv:0809.0243

Date: Mon, 1 Sep 2008 13:36:02 GMT (233kb)

Title: Dispersion compensation in atom interferometry by a Sagnac phase

Authors: Marion Jacquey (LCAR), Alain Miffre (LCAR), G\'erard Tr\'enec (LCAR),

Matthias B\"uchner (LCAR), Jacques Vigu\'e (LCAR), Alexander Cronin

Categories: quant-ph

Journal-ref: Physical Review A: Atomic, Molecular and Optical Physics 78 (2008)

013638

DOI: 10.1103/PhysRevA.78.013638

\\

We reanalyzed our atom interferometer measurement of the electric

polarizability of lithium now accounting for the Sagnac effect due to Earth

rotation. The resulting correction to the polarizability is very small but the

visibility as a function of the applied phase shift is now better explained.

The fact that the Sagnac and polarizability phase shifts are both proportional

to $v^{-1}$, where $v$ is the atom velocity, suggests that a phase shift of the

Sagnac type could be used as a counterphase to compensate the electric

polarizability phase shift. This exact compensation opens the way to higher

accuracy measurements of atomic polarizabilities and we discuss how this can be

practically done and the final limitations of the proposed technique.

\\ ( http://arxiv.org/abs/0809.0243 , 233kb)

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arXiv:0809.0288

Date: Mon, 1 Sep 2008 18:08:03 GMT (913kb)

Title: Dynamic optical lattices: two-dimensional rotating and accordion

lattices for ultracold atoms

Authors: R. A. Williams, J. D. Pillet, S. Al-Assam, B. Fletcher, and C. J. Foot

Categories: quant-ph

Comments: 7 pages, 6 figures

\\

We demonstrate a novel experimental arrangement which rotates a 2D optical

lattice at frequencies up to several kilohertz. Ultracold atoms in such a

rotating lattice can be used for the direct quantum simulation of strongly

correlated systems under large effective magnetic fields, allowing

investigation of phenomena such as the fractional quantum Hall effect. Our

arrangement also allows the periodicity of a 2D optical lattice to be varied

dynamically, producing a 2D accordion lattice.

\\ ( http://arxiv.org/abs/0809.0288 , 913kb)

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arXiv:0809.0149

Date: Sun, 31 Aug 2008 20:23:56 GMT (412kb)

Title: Off-resonant Raman transitions impact in an atom interferometer

Authors: A. Gauguet (SYRTE), Tanja Mehlst\"aubler (SYRTE), Thomas L\'ev\`eque

(SYRTE), J. Le Gou\"et (SYRTE), Oualid Chaibi (SYRTE), B. Canuel (SYRTE),

Andre Clairon (SYRTE), Franck Pereira Dos Santos (SYRTE), Arnaud Landragin

(SYRTE)

Categories: physics.atom-ph

\\

We study the influence of off-resonant two photon transitions on high

precision measurements with atom interferometers based on stimulated Raman

transitions. These resonances induce a two photon light shift on the resonant

Raman condition. The impact of this effect is investigated in two highly

sensitive experiments: a gravimeter and a gyroscope-accelerometer. We show that

it can lead to significant systematic phase shifts, which have to be taken into

account in order to achieve best performances in term of accuracy and

stability.

\\ ( http://arxiv.org/abs/0809.0149 , 412kb)

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arXiv:0809.0312

Date: Mon, 1 Sep 2008 20:01:32 GMT (182kb)

Title: Probing spatial spin correlations of ultracold gases by quantum noise

spectroscopy

Authors: G. M. Bruun, Brian M. Andersen, Eugene Demler and Anders S.

S{\o}rensen

Categories: cond-mat.other

Comments: 4 pages, 3 figures

\\

Spin noise spectroscopy with a single laser beam is demonstrated

theoretically to provide a direct probe of the spatial correlations of cold

fermionic gases. We show how the generic many-body phenomena of anti-bunching,

pairing, antiferromagnetic, and algebraic spin liquid correlations can be

revealed in the measured spin noise as a function of laser width, temperature,

and frequency.

\\ ( http://arxiv.org/abs/0809.0312 , 182kb)

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arXiv:0809.0350

Date: Tue, 2 Sep 2008 05:37:24 GMT (871kb)

Title: Stability of superfluid Fermi gases in optical lattices

Authors: Yoshihiro Yunomae, Ippei Danshita, Daisuke Yamamoto, Nobuhiko Yokoshi,

and Shunji Tsuchiya

Categories: cond-mat.other

Comments: 4 pages, 4 figures, conference proceeding for ISQM-TOKYO'08

\\

Fermionic superfluid flow and its stability are theoretically investigated.

We consider the Fermi gases in moving one- and two-dimensional optical

lattices, and calculate the excitation spectrum on them. It is found that

low-lying excitations, called as Anderson-Bogoliubov (AB) mode, exhibit a

roton-like structure in a short-wavelength regime. Moreover, with increasing

lattice velocity, one of the roton-like minima reaches zero before the pair

breaking occurs. This means that the superfluid Fermi gases can be destabilized

due to the spontaneous emission of the roton-like AB mode instead of due to the

Cooper pair breaking.

\\ ( http://arxiv.org/abs/0809.0350 , 871kb)

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arXiv:0809.0440

Date: Tue, 2 Sep 2008 14:26:16 GMT (810kb,D)

Title: Transition from a Spin Luttinger-Liquid to a Bose-Einstein Condensate of

Magnons in the Quantum Spin Ladder (C5H12N)2CuBr4

Authors: B. Thielemann, Ch. R\"uegg, K. Kiefer, H.M. R{\o}nnow, P. Bouillot, C.

Kollath, E. Orignac, R. Citro, T. Giamarchi, A. M. L\"auchli, D. Biner, K.

Kr\"amer, F. Wolff-Fabris, V. Zapf, M. Jaime, J. Stahn, N.B. Christensen, B.

Grenier, D.F. McMorrow, J. Mesot

Categories: cond-mat.str-el

Comments: 4 pages, 4 figures

\\

The transition from a magnetic field-tuned spin Luttinger-liquid with

algebraic spin correlations to a Bose-Einstein Condensate of magnons with

long-range magnetic order is investigated in the two-leg spin ladder material

bis(piperidinium)tetrabromocuprate(II) (C5H12N)2CuBr4. By neutron diffraction

and measurements of the magnetocaloric effect we show that the ordering

temperature, transverse and longitudinal magnetizations, and critical behavior

are highly dominated by the tunable one-dimensional physics of the

weakly-coupled spin Luttinger-liquids. Our experimental results are in

excellent agreement with theoretical calculations with renormalized mean-field

interaction parameters.

\\ ( http://arxiv.org/abs/0809.0440 , 810kb)

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arXiv:0809.0449

Date: Tue, 2 Sep 2008 14:59:58 GMT (185kb)

Title: Point processes in arbitrary dimension from fermionic gases, random

matrix theory, and number theory

Authors: Salvatore Torquato, A. Scardicchio and Chase E Zachary

Categories: cond-mat.stat-mech

Comments: 40 pages, 11 figures, 1 table, iopart

\\

It is well known that one can map certain properties of random matrices,

fermionic gases, and zeros of the Riemann zeta function to a unique point

process on the real line. Here we analytically provide exact generalizations of

such a point process in d-dimensional Euclidean space for any d, which are

special cases of determinantal processes. In particular, we obtain the

n-particle correlation functions for any n, which completely specify the point

processes. We also demonstrate that spin-polarized fermionic systems have these

same n-particle correlation functions in each dimension. The point processes

for any d are shown to be hyperuniform. The latter result implies that the pair

correlation function tends to unity for large pair distances with a decay rate

that is controlled by the power law r^[-(d+1)]. We graphically display one- and

two-dimensional realizations of the point processes in order to vividly reveal

their "repulsive" nature. Indeed, we show that the point processes can be

characterized by an effective "hard-core" diameter that grows like the square

root of d. The nearest-neighbor distribution functions for these point

processes are also evaluated and rigorously bounded. Among other results, this

analysis reveals that the probability of finding a large spherical cavity of

radius r in dimension d behaves like a Poisson point process but in dimension

d+1 for large r and finite d. We also show that as d increases, the point

process behaves effectively like a sphere packing with a coverage fraction of

space that is no denser than 1/2^d.

\\ ( http://arxiv.org/abs/0809.0449 , 185kb)

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arXiv:0809.0340

Date: Tue, 2 Sep 2008 02:52:37 GMT (96kb)

Title: Radio frequency association of heteronuclear Feshbach molecules

Authors: C. Klempt, T. Henninger, O. Topic, M. Scherer, L.Kattner, W. Ertmer

and J. Arlt

Categories: quant-ph

Comments: 5 pages, 4 figures

\\

We present a detailed analysis of the production efficiency of weakly bound

heteronuclear KRb Feshbach molecules using radio frequency association in a

harmonic trap. The efficiency was measured in a wide range of temperatures,

binding energies and radio frequencies. A comprehensive analytical model is

shown to provide a detailed understanding of the observed asymmetric spectra

and a good quantitative agreement with the measured production rates. This

fully consistent model provides a deep understanding of the molecule

association process and paves the way for future experiments which rely on

Feshbach molecules e.g. for the production of deeply bound molecules.

\\ ( http://arxiv.org/abs/0809.0340 , 96kb)

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arXiv:0809.0399

Date: Tue, 2 Sep 2008 10:58:37 GMT (322kb)

Title: A vapor cell based on dispensers for laser spectroscopy

Authors: E. M. Bridge, J. Millen, C. S. Adams, M. P. A. Jones

Categories: physics.atom-ph physics.ins-det

Comments: 8 pages, 3 figures

\\

We describe a simple strontium vapor cell for laser spectroscopy experiments.

Strontium vapor is produced using an electrically heated commercial dispenser

source. The sealed cell operates at room temperature, and without a buffer gas

or vacuum pump. The cell was characterised using laser spectroscopy, and was

found to offer stable and robust operation, with an estimated lifetime of

* >10,000 hours. By changing the dispenser, this technique can be readily
*

extended to other alkali and alkaline earth elements.

\\ ( http://arxiv.org/abs/0809.0399 , 322kb)

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arXiv:0809.0505

Date: Wed, 3 Sep 2008 08:17:46 GMT (276kb)

Title: Metastable superfluidity of repulsive fermionic atoms in optical

lattices

Authors: Achim Rosch, David Rasch, Benedikt Binz, Matthias Vojta

Categories: cond-mat.other cond-mat.supr-con

Comments: 4 pages, 3 figs

\\

Doubly occupied states of the fermionic Hubbard model have an exponentially

large lifetime in the limit of strong repulsive interactions U. We show that

this property can be used to prepare a metastable s-wave superfluid state for

fermionic atoms in optical lattices described by a large-U Hubbard model. When

an initial band-insulating state is expanded, the doubly occupied sites Bose

condense. A mapping to the ferromagnetic Heisenberg model in an external field

allows for a reliable solution of the problem. Nearest-neighbor repulsion is

important in stabilizing superfluidity.

\\ ( http://arxiv.org/abs/0809.0505 , 276kb)

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arXiv:0809.0586

Date: Wed, 3 Sep 2008 09:46:06 GMT (62kb)

Title: Reverse engineering in many-body quantum physics: What many-body system

corresponds to an effective single-particle equation?

Authors: J. P. Coe, K. Capelle, and I. D'Amico

Categories: cond-mat.other

Comments: 4 pages, 2 figures

\\

The mapping, exact or approximate, of a many-body problem onto an effective

single-body problem is one of the most widely used conceptual and computational

tools of physics. Here, we propose and investigate the inverse map of effective

approximate single-particle equations onto the corresponding many-particle

system. This approach allows us to understand which interacting system a given

single-particle approximation is actually describing, and how far this is from

the original physical many-body system. We illustrate the resulting reverse

engineering process by means of the Kohn-Sham equations of density-functional

theory. In this application, our procedure sheds light on the non-locality of

the density-potential mapping of DFT, and on the self-interaction error

inherent in approximate density functionals.

\\ ( http://arxiv.org/abs/0809.0586 , 62kb)

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arXiv:0809.0706

Date: Thu, 4 Sep 2008 13:33:30 GMT (831kb)

Title: Effective Action Approach for Quantum Phase Transitions in Bosonic

Lattices

Authors: Barry Bradlyn, Francisco Ednilson A. dos Santos, Axel Pelster

Categories: cond-mat.stat-mech

Comments: 30 pages, 7 figures

\\

Based on standard field-theoretic considerations, we develop an effective

action approach for investigating quantum phase transitions in lattice Bose

systems at arbitrary temperature. We begin by adding to the Hamiltonian of

interest a symmetry breaking source term. Using time-dependent perturbation

theory, we then expand the grand-canonical free energy as a double power series

in both the tunneling and the source term. From here, an order parameter field

is introduced in the standard way, and the underlying effective action is

derived via a Legendre transformation. Determining the Ginzburg-Landau

expansion to first order in the tunneling term, expressions for the Mott

insulator-superfluid phase boundary, condensate density, average particle

number, and compressibility are derived and analyzed in detail. Additionally,

excitation spectra in the ordered phase are found by considering both

longitudinal and transverse variations of the order parameter. Finally, these

results are applied to the concrete case of the Bose-Hubbard Hamiltonian on a

three dimensional cubic lattice, and compared with the corresponding results

from mean-field theory. Although both approaches yield the same Mott insulator

- superfluid phase boundary to first order in the tunneling, the predictions of

our effective action theory turn out to be superior to the mean-field results

deeper into the superfluid phase.

\\ ( http://arxiv.org/abs/0809.0706 , 831kb)

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arXiv:0809.0747

Date: Thu, 4 Sep 2008 04:43:28 GMT (17kb)

Title: Semiclassical theory of the trapped quasi-2D Bose gas

Authors: R.N. Bisset, D. Baillie and P.B. Blakie

Categories: cond-mat.other

Comments: 5 pages, 2 figures

\\

We develop a Hartree-Fock meanfield model for the harmonically trapped

quasi-2D Bose gas. This method is valid in the non-degenerate regime where

density fluctuations are approximately Gaussian. We compare our predictions to

a meanfield theory suggested by Holzmann et al., [Europhys. Lett., 82, 30001

(2008)], which involves a simplification of the meanfield interaction term. We

discuss the universal behavior of the Berezinskii-Kosterlitz-Thouless

transition for the uniform Bose gas and how this result should be extended to

the trapped case. Using our meanfield theory we are able to provide a

lower-bound for the transition temperature.

\\ ( http://arxiv.org/abs/0809.0747 , 17kb)

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arXiv:0809.0768

Date: Thu, 4 Sep 2008 08:27:15 GMT (1894kb)

Title: Coherent control of dressed matter waves

Authors: Alessandro Zenesini and Hans Lignier and Donatella Ciampini and Oliver

Morsch and Ennio Arimondo

Categories: cond-mat.other quant-ph

Comments: 5 pages, 4 figures

\\

By moving the pivot of a pendulum rapidly up and down one can create a stable

position with the pendulum's bob above the pivot rather than below it. This

surprising and counterintuitive phenomenon is a widespread feature of driven

systems and carries over into the quantum world. Even when the static

properties of a quantum system are known, its response to an explicitly

time-dependent variation of its parameters may be highly nontrivial, and

qualitatively new states can appear that were absent in the original system. In

quantum mechanics the archetype for this kind of behaviour is an atom in a

radiation field, which exhibits a number of fundamental phenomena such as the

modification of its g-factor in a radio-frequency field and the dipole force

acting on an atom moving in a spatially varying light field. These effects can

be successfully described in the so-called dressed atom picture. Here we show

that the concept of dressing can also be applied to macroscopic matter waves,

and that the quantum states of "dressed matter waves" can be coherently

controlled. In our experiments we use Bose-Einstein condensates in driven

optical lattices and demonstrate that the many-body state of this system can be

adiabatically and reversibly changed between a superfluid and a Mott insulating

state by varying the amplitude of the driving. Our setup represents a versatile

testing ground for driven quantum systems, and our results indicate the

direction towards new quantum control schemes for matter waves.

\\ ( http://arxiv.org/abs/0809.0768 , 1894kb)

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arXiv:0809.0771

Date: Thu, 4 Sep 2008 14:47:21 GMT (414kb)

Title: Visibility of Cold Atomic Gases in Optical Lattices for Finite

Temperatures

Authors: Alexander Hoffmann and Axel Pelster

Categories: cond-mat.stat-mech

Comments: Author Information under

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

\\

In nearly all experiments with ultracold atoms time-of-flight pictures are

the only data available. In this paper we present an analytical strong-coupling

calculation for those time-of-flight pictures of bosons in an optical lattice

in the Mott phase. This allows us to determine the visibility, which quantifies

the contrast of peaks in the time-of-flight pictures, and we suggest how to use

it as a thermometer.

\\ ( http://arxiv.org/abs/0809.0771 , 414kb)

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Just for interest's sake:

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arXiv:0809.0290

Date: Mon, 1 Sep 2008 18:25:14 GMT (37kb)

Title: What are scientific leaders? The introduction of a normalized impact

factor

Authors: George E. A. Matsas

Categories: physics.soc-ph physics.data-an

Comments: 2 pages and 2 figures

\\

We define a normalized impact factor suitable to assess in a simple way both

the strength of scientific communities and the research influence of

individuals. We define those ones with $NIF \geq 1$ as being scientific leaders

since they would influence their peers at least as much as they are influenced

by them. The NIF is distinguished because (a) this has a clear and universal

meaning being applicable with equal efficiency to individuals belonging to

scientific communities with quite different publication and citation traditions

and (b) this is robust against self-citation expedient. This is eventually

applied to a community derived from the list of outstanding referees recognized

by the American Physical Society in 2008.

\\ ( http://arxiv.org/abs/0809.0290 , 37kb)

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arXiv:0809.0522

Date: Tue, 2 Sep 2008 21:33:02 GMT (81kb)

Title: The first-mover advantage in scientific publication

Authors: M. E. J. Newman

Categories: physics.soc-ph

Comments: 7 pages, 3 figures

\\

Mathematical models of the scientific citation process predict a strong

"first-mover" effect under which the first papers in a field will, essentially

regardless of content, receive citations at a rate enormously higher than

papers published later. Moreover papers are expected to retain this advantage

in perpetuity -- they should receive more citations indefinitely, no matter how

many other papers are published after them. We test this conjecture against

data from a selection of fields and in several cases find a first-mover effect

of a magnitude similar to that predicted by the theory. Were we wearing our

cynical hat today, we might say that the scientist who wants to become famous

is better off -- by a wide margin -- writing a modest paper in next year's

hottest field than an outstanding paper in this year's. On the other hand,

there are some papers, albeit only a small fraction, that buck the trend and

attract significantly more citations than theory predicts despite having

relatively late publication dates. We suggest that papers of this kind, though

they often receive comparatively few citations overall, are probably worthy of

our attention.

\\ ( http://arxiv.org/abs/0809.0522 , 81kb)

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The replacements:

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arXiv:hep-th/0501058 (*cross-listing*)

replaced with revised version Fri, 29 Aug 2008 07:15:49 GMT (215kb)

Title: Entanglement Induced Fluctuations of Cold Bosons

Authors: Ram Brustein, Amos Yarom

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

Comments: Replaced with published version. Added calculations, explanations and

clarifications, results unchanged

\\ ( http://arxiv.org/abs/hep-th/0501058 , 215kb)

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arXiv:0801.1743

replaced with revised version Fri, 29 Aug 2008 03:47:28 GMT (642kb)

Title: Temperature Effects in a Fermi Gas with Population Imbalance

Authors: Heron Caldas, and A. L. Mota

Categories: cond-mat.str-el cond-mat.supr-con hep-ph nucl-th

Comments: 9 pages, 12 figures; minor typos corrected, references added

Journal-ref: J. Stat. Mech. P08013 (2008)

\\ ( http://arxiv.org/abs/0801.1743 , 642kb)

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arXiv:0808.2652

replaced with revised version Thu, 28 Aug 2008 20:42:42 GMT (447kb)

Title: Squeezing Out the Entropy of Fermions in Optical Lattices

Authors: Tin-Lun Ho and Qi Zhou

Categories: cond-mat.other

Comments: 6 pages, 3 figures, misprints corrected

\\ ( http://arxiv.org/abs/0808.2652 , 447kb)

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arXiv:0712.2256

replaced with revised version Sun, 31 Aug 2008 19:36:40 GMT (257kb)

Title: Spin-orbit coupled Bose-Einstein condensates

Authors: Tudor Stanescu, Brandon Anderson and Victor Galitski

Categories: cond-mat.other cond-mat.stat-mech quant-ph

Comments: published version, 10 pages, 4 figures

Journal-ref: Phys. Rev. A 78, 023616 (2008)

DOI: 10.1103/PhysRevA.78.023616

\\ ( http://arxiv.org/abs/0712.2256 , 257kb)

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arXiv:0804.0109

replaced with revised version Sat, 30 Aug 2008 07:08:33 GMT (213kb)

Title: Mechanisms for Lasing with Cold Atoms as the Gain Medium

Authors: William Guerin (INLN), Franck Michaud (INLN), Robin Kaiser (INLN)

Categories: physics.atom-ph cond-mat.dis-nn physics.optics

Journal-ref: Physical Review Letters 101 (2008) 093002

DOI: 10.1103/PhysRevLett.101.093002

\\ ( http://arxiv.org/abs/0804.0109 , 213kb)

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arXiv:0712.2256

replaced with revised version Sun, 31 Aug 2008 19:36:40 GMT (257kb)

Title: Spin-orbit coupled Bose-Einstein condensates

Authors: Tudor Stanescu, Brandon Anderson and Victor Galitski

Categories: cond-mat.other cond-mat.stat-mech quant-ph

Comments: published version, 10 pages, 4 figures

Journal-ref: Phys. Rev. A 78, 023616 (2008)

DOI: 10.1103/PhysRevA.78.023616

\\ ( http://arxiv.org/abs/0712.2256 , 257kb)

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arXiv:0804.2272

replaced with revised version Wed, 3 Sep 2008 14:43:22 GMT (11kb)

Title: Quantum hydrodynamics and nonlinear differential equations for

degenerate Fermi gas

Authors: E. Bettelheim, A. G. Abanov, and P. Wiegmann

Categories: cond-mat.mes-hall cond-mat.str-el math-ph math.MP nlin.SI

Comments: 10+ pages, appendix with some technical details is added

Journal-ref: J. Phys. A: Math. Theor. 41 (2008) 392003

\\ ( http://arxiv.org/abs/0804.2272 , 11kb)

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arXiv:0806.3107

replaced with revised version Wed, 3 Sep 2008 04:14:54 GMT (512kb)

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: 7 pages, 5 figures

\\ ( http://arxiv.org/abs/0806.3107 , 512kb)

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arXiv:0711.2697

replaced with revised version Thu, 4 Sep 2008 18:54:41 GMT (177kb)

Title: Exact exponents of edge singularities in dynamic correlation functions

of 1D Bose gas

Authors: Adilet Imambekov and Leonid I. Glazman

Categories: cond-mat.str-el

Comments: minor misprints in published version fixed

Journal-ref: Phys. Rev. Lett. 100, 206805 (2008)

DOI: 10.1103/PhysRevLett.100.206805

\\ ( http://arxiv.org/abs/0711.2697 , 177kb)

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arXiv:0805.3047

replaced with revised version Thu, 4 Sep 2008 15:53:08 GMT (178kb)

Title: Critical Temperature Curve in the BEC-BCS Crossover

Authors: Evgeni Burovski, Evgeny Kozik, Nikolay Prokof'ev, Boris Svistunov,

Matthias Troyer

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

Comments: revtex, 4 pages, 3 figures, published version

Journal-ref: Phys. Rev. Lett. 101, 090402 (2008)

\\ ( http://arxiv.org/abs/0805.3047 , 178kb)

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arXiv:0808.2963

replaced with revised version Wed, 3 Sep 2008 21:21:27 GMT (567kb,D)

Title: A High Phase-Space-Density Gas of Polar Molecules

Authors: K.-K. Ni, S. Ospelkaus, M. H. G. de Miranda, A. Pe'er, B. Neyenhuis,

J. J. Zirbel, S. Kotochigova, P. S. Julienne, D. S. Jin, J. Ye

Categories: quant-ph cond-mat.other

Comments: 21 pages, 6 figures

\\ ( http://arxiv.org/abs/0808.2963 , 567kb)

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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 Thu Sep 25 2008 - 11:06:56 EST

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