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

Date: Fri, 1 May 2009 10:04:41 +1000

Date: Fri, 1 May 2009 10:04:41 +1000

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

Dear subscribers,

There were 27 new preprints and 9 replacements for this week.

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arXiv:0901.4778

Date: Thu, 29 Jan 2009 21:01:54 GMT (342kb)

Title: Non-adiabaticity and nonlinearity of a many-particle Landau-Zener

problem: classical adiabatic theory approach

Authors: A.P. Itin, P. T\"orm\"a

Categories: cond-mat.stat-mech

Comments: submitted to Phys. Rev. Lett

\\

We consider nonlinear dynamics of an interacting many-particle system with a

slowly changing parameter: a time-dependent Dicke model, which represents a

many-body generalization of the Landau-Zener model. Adiabaticity is destroyed

when a parameter crosses a critical value, even at very slow sweeping rates of

a parameter. Applying semiclassical analysis based on concepts of classical

adiabatic invariants, we derive a formula which accurately describes particle

distributions in the Hilbert space at wide range of parameters and initial

conditions of the system.

\\ ( http://arxiv.org/abs/0901.4778 , 342kb)

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arXiv:0901.4808

Date: Fri, 30 Jan 2009 00:23:27 GMT (691kb)

Title: Anomalous Spin segregation in a weakly interacting two-component Fermi

gas

Authors: Stefan S. Natu, Erich J. Mueller

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

Comments: 4 pages, 3 figures

\\

We explain the spin segregation seen at Duke in a two-component gas of 6Li

[Du, Luo, Clancy and Thomas, Phys. Rev. Lett. 101,150401 (2008)] as a

mean-field effect describable via a collisionless Boltzmann equation. As seen

in experiments, we find that slight differences in the trapping potentials in

the two spin states drive small spin currents. Hartree-Fock type interactions

convert these currents into a redistribution of populations in energy space,

and consequently a long lived spin texture develops. We explore the interaction

strength dependence of these dynamics, finding close agreement with experiment.

\\ ( http://arxiv.org/abs/0901.4808 , 691kb)

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arXiv:0901.4951

Date: Fri, 30 Jan 2009 18:36:22 GMT (121kb)

Title: Perturbation theory for the Nonlinear Schroedinger Equation with a

random potential

Authors: Shmuel Fishman, Yevgeny Krivolapov and Avy Soffer

Categories: cond-mat.dis-nn

Comments: 29 pages, 7 figures

\\

A perturbation theory for the NLSE in 1D on a lattice was developed. The

small parameter is the strength of the nonlinearity. For this purpose secular

terms were removed and a probabilistic bound on small denominators was

developed. It was shown that the number of terms grows exponentially with the

order. The results of the perturbation theory are compared with numerical

calculations. An estimate on the remainder is obtained and it is demonstrated

that the series is asymptotic.

\\ ( http://arxiv.org/abs/0901.4951 , 121kb)

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arXiv:0901.4779

Date: Thu, 29 Jan 2009 21:31:58 GMT (186kb,D)

Title: Entangled Mechanical Oscillators

Authors: J. D. Jost, J. P. Home, J. M. Amini, D. Hanneke, R. Ozeri, C. Langer,

J. J. Bollinger, D. Leibfried, and D. J. Wineland

Categories: quant-ph

Comments: 7 pages, 2 figures

\\

Hallmarks of quantum mechanics include superposition and entanglement. In the

context of large complex systems, these features should lead to situations like

Schrodinger's cat, which exists in a superposition of alive and dead states

entangled with a radioactive nucleus. Such situations are not observed in

nature. This may simply be due to our inability to sufficiently isolate the

system of interest from the surrounding environment -- a technical limitation.

Another possibility is some as-of-yet undiscovered mechanism that prevents the

formation of macroscopic entangled states. Such a limitation might depend on

the number of elementary constituents in the system or on the types of degrees

of freedom that are entangled. One system ubiquitous to nature where

entanglement has not been previously demonstrated is distinct mechanical

oscillators. Here we demonstrate deterministic entanglement of separated

mechanical oscillators, consisting of the vibrational states of two pairs of

atomic ions held in different locations. We also demonstrate entanglement of

the internal states of an atomic ion with a distant mechanical oscillator.

\\ ( http://arxiv.org/abs/0901.4779 , 186kb)

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arXiv:0901.4789

Date: Thu, 29 Jan 2009 21:51:28 GMT (243kb)

Title: Ultra-bright biphoton emission from an atomic vapor based on

Doppler-free four-wave-mixing and collective emission

Authors: Y. P. Huang and M. G. Moore

Categories: quant-ph

\\

We propose a novel `butterfly' level scheme to generate highly correlated

photon pairs from atomic vapors. With multi-photon Doppler-free pumping,

background Rayleigh scattering is dipole-forbidden and collective emission is

permitted in all directions. This results in usable pairs generated

simultaneously in the full $4\pi$ solid angle. Collecting these pairs can

produce photon pairs at a rate of $\sim 10^{12}$ per second, given only

moderate ensemble sizes of $\sim 10^6$ atoms.

\\ ( http://arxiv.org/abs/0901.4789 , 243kb)

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arXiv:0901.4896

Date: Fri, 30 Jan 2009 14:46:27 GMT (744kb)

Title: Quantum phase diagram of fermion mixtures with population imbalance in

one-dimensional optical lattices

Authors: B. Wang, Han-Dong Chen, and S. Das Sarma

Categories: quant-ph

\\

With a recently developed time evolving block decimation (TEBD) algorithm, we

numerically study the ground state quantum phase diagram of fermi mixtures with

attractive inter-species interactions loaded in one-dimensional optical

lattices. For our study, we adopt a general asymmetric Hubbard model (AHM) with

species-dependent tunneling rates to incorporate the possibility of mass

imbalance in the mixtures. We find clear signatures for the existence of a

Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase in this model in the presence of

population imbalance. Our simulation also reveals that in the presence of mass

imbalance, the parameter space for FFLO states shrinks or even completely

vanishes depending on the strength of the attractive interaction and the degree

of mass imbalance.

\\ ( http://arxiv.org/abs/0901.4896 , 744kb)

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arXiv:0902.0005

Date: Mon, 2 Feb 2009 17:01:06 GMT (101kb)

Title: Getting into Shape: Efficient Cooling Scheme for Fermionic Atoms in

Optical Lattices

Authors: Jean-Sebastien Bernier, Corinna Kollath, Antoine Georges, Lorenzo De

Leo, Fabrice Gerbier, Christophe Salomon, Michael K\"ohl

Categories: cond-mat.str-el

Comments: 4+ pages, 3 figures

\\

We propose an experimental procedure to cool fermionic atoms loaded into an

optical lattice. The central idea is to spatially divide the system into

entropy-rich and -poor regions by shaping the confining potential profile.

Atoms in regions of high entropy per particle are subsequently isolated from

the system. We discuss how to experimentally carry out this proposal, and

perform a quantitative study of its efficiency. We find that the entropy per

particle, $s$, can typically be reduced by a factor of 10 such that entropies

lower than $s/k_B \sim 0.2$ can be reached. Cooling into highly sought-after

quantum phases (such as an antiferromagnet) can thus be achieved. We show that

this procedure is robust against variations of the experimental conditions.

\\ ( http://arxiv.org/abs/0902.0005 , 101kb)

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arXiv:0902.0107

Date: Sun, 1 Feb 2009 06:19:39 GMT (369kb)

Title: One-Dimensional Anderson Localization in Certain Correlated Random

Potentials

Authors: Pierre Lugan (LCFIO), Alain Aspect (LCFIO), Laurent Sanchez-Palencia

(LCFIO), Dominique Delande (LKB - Jussieu), Beno\^it Gr\'emaud (LKB -

Jussieu, IPAL, CNRS), Cord A. M\"uller (LKB - Jussieu), Christian Miniatura

(IPAL, CNRS, INLN)

Categories: cond-mat.other

\\

We investigate Anderson localization in weak 1D speckle potentials. We show

that long-range correlations induce effective mobility edges corresponding to

sharp crossovers between regions here localization lengths differ by orders of

magnitude. Using perturbation theory, we derive analytical formulas up to two

orders beyond Born approximation which prove in excellent agreement with exact

numerical calculations. Finally, we analyze our findings in the light of a

diagrammatic approach.

\\ ( http://arxiv.org/abs/0902.0107 , 369kb)

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arXiv:0902.0172

Date: Mon, 2 Feb 2009 00:26:57 GMT (111kb)

Title: Effects of a dilute gas of fermions on the superfluid-insulator phase

diagram of the Bose-Hubbard model

Authors: Sumanta Tewari, Roman Lutchyn, S. Das Sarma

Categories: cond-mat.str-el

Comments: 16 pages, 3 eps figures

\\

Building on the work of Fisher et al. (Phys. Rev. B 40, 546 (1989)), we

develop a framework for perturbation theory in the Bose-Hubbard model and apply

it to calculate the effects of a degenerate gas of spin-polarized fermions

interacting by contact interactions with the constituent bosons. For the

single-band Bose-Hubbard model, the only non-trivial effect of the fermions is

to induce an effective space- and time-dependent density-density interaction

among the bosons. Using a path integral formulation, we develop the appropriate

theory describing the perturbative effects of this fermion-mediated interaction

(fermionic screening) on the generic superfluid-insulator phase diagram. For

the single-band Bose-Hubbard model, we find that the net effect of the fermions

is to inherently suppress the Mott-insulating lobes and enhance the area

occupied by the superfluid phase in the phase diagram. For the more general

multi-band Bose-Hubbard model, we find that, in addition to the fermion

screening of the boson interactions, the virtual excitations of the bosons to

the higher Bloch bands coupled with the contact interactions with the fermions

result in an effective increase of the boson on-site repulsion. If this

renormalization of the boson on-site potential is dominant over the fermion

screening of the boson interactions, the area of the Mott insulating lobes of

the Bose-Hubbard phase diagram will be enhanced for either sign of the

boson-fermion interactions, as seen in recent experiments.

\\ ( http://arxiv.org/abs/0902.0172 , 111kb)

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arXiv:0902.0327

Date: Mon, 2 Feb 2009 18:03:56 GMT (1548kb)

Title: Classical and quantum analysis of a heterotriatomic molecular

Bose-Einstein-condensate model

Authors: A. P. Tonel, C. C. N. Kuhn, G. Santos, A. Foerster, I. Roditi and Z.

V. T. Santos

Categories: cond-mat.other

Comments: 9 pages, 7 figures

Journal-ref: Phys. Rev. A 79, 013624 (2009) [9 pages]

DOI: 10.1103/PhysRevA.79.013624

\\

We investigate an integrable Hamiltonian modeling a heterotriatomic molecular

Bose-Einstein condensate. This model describes a mixture of two species of

atoms in different proportions, which can combine to form a triatomic molecule.

Beginning with a classical analysis, we determine the fixed points of the

system. Bifurcations of these points separate the parameter space into

different regions. Three distinct scenarios are found, varying with the atomic

population imbalance. This result suggests the ground-state properties of the

quantum model exhibit a sensitivity on the atomic population imbalance, which

is confirmed by a quantum analysis using different approaches, such as the

ground-state expectation values, the behavior of the quantum dynamics, the

energy gap, and the ground-state fidelity.

\\ ( http://arxiv.org/abs/0902.0327 , 1548kb)

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arXiv:0902.0234

Date: Mon, 2 Feb 2009 10:06:08 GMT (846kb)

Title: Theory and experimental verification of Kapitza-Dirac-Talbot-Lau

interferometry

Authors: Klaus Hornberger, Stefan Gerlich, Hendrik Ulbricht, Lucia

Hackerm\"uller, Stefan Nimmrichter, Ilya V. Goldt, Olga Boltalina, Markus

Arndt

Categories: quant-ph

Comments: 24 pages, 6 figures

\\

Kapitza-Dirac-Talbot-Lau interferometry (KDTLI) has recently been established

for demonstrating the quantum wave nature of large molecules. A phase space

treatment permits us to derive closed equations for the near-field interference

pattern, as well as for the Moire-type pattern that would arise if the

molecules were to be treated as classical particles. The model provides a

simple and elegant way to account for the molecular phase shifts related to the

optical dipole potential as well as for the incoherent effect of photon

absorption at the second grating. We present experimental results for different

molecular masses, polarizabilities and absorption cross sections using

fullerenes and fluorofullerenes and discuss the alignment requirements. Our

results with C60 and C70, C60F36 and C60F48 verify the theoretical description

to a high degree of precision.

\\ ( http://arxiv.org/abs/0902.0234 , 846kb)

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arXiv:0902.0109

Date: Mon, 2 Feb 2009 19:59:19 GMT (44kb)

Title: Suspension of atoms and gravimetry using a pulsed standing wave

Authors: K. J. Hughes, J. H. T. Burke, C. A. Sackett

Categories: physics.atom-ph

Comments: 5 pages, 3 figures

\\

Atoms from an otherwise unconfined 87Rb condensate are shown to be suspended

against gravity using repeated reflections from a pulsed optical standing wave.

Reflection efficiency was optimized using a triple-pulse sequence that,

theoretically, provides accuracies better than 99.9%. Experimentally, up to 100

reflections are observed, leading to dynamical suspension for over 100 ms. The

velocity sensitivity of the reflections can be used to determine the local

gravitational acceleration. Further, a gravitationally sensitive atom

interferometer was implemented using the suspended atoms, with packet coherence

maintained for a similar time. These techniques could be useful for the precise

measurement of gravity when it is impractical to allow atoms to fall freely

over a large distance.

\\ ( http://arxiv.org/abs/0902.0109 , 44kb)

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arXiv:0902.0366

Date: Mon, 2 Feb 2009 21:00:06 GMT (25kb)

Title: Ground State Properties of Cold Bosonic Atoms At Large Scattering

Lengths

Authors: Jun Liang Song, Fei Zhou (UBC)

Categories: cond-mat.other

\\

In this letter, we study bosonic atoms at large scattering lengths using a

variational method where the condensation amplitude is a variational parameter.

We further examine momentum distribution functions, chemical potentials and

speed of sound, and spatial density profiles of cold bosonic atoms in a trap in

this limit. The later two properties turn out to bear similarities of those of

Fermi gases. Estimates obtained here are applicable near Feshbach resonances,

particularly when the fraction of atoms forming trimer structures is small and

can be tested in future cold atom experiments.

\\ ( http://arxiv.org/abs/0902.0366 , 25kb)

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arXiv:0902.0388

Date: Mon, 2 Feb 2009 21:58:39 GMT (271kb)

Title: Dispersive spectrum and orbital order of spinless p-band fermions in an

optical lattice

Authors: Xiancong Lu and E. Arrigoni

Categories: cond-mat.str-el

Comments: 7 pages, 6 figures

\\

We study single-particle properties of a spinless p-band correlated fermionic

gas in an optical lattice by means of a variational cluster approach. The

single-particle spectral function is almost flat at half-filling and develops a

strongly dispersive behavior at lower fillings. The competition between

different orbital orderings is studied as a function of filling. We observe an

evolution between "antiferromagnetic" orbital order at and close to

half-filling to "ferromagnetic" orbital order at lower fillings. We discuss the

behavior of the momentum distribution for different values of the on-site

interaction. Finally, we introduce a new integration contour in the complex

plane which allows to efficiently carry out a sum over Matsubara frequencies.

\\ ( http://arxiv.org/abs/0902.0388 , 271kb)

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arXiv:0902.0489

Date: Tue, 3 Feb 2009 14:50:25 GMT (187kb)

Title: ac-driven atomic quantum motor

Authors: A. V. Ponomarev, S. Denisov, P. Hanggi

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

Comments: 4 pages, 4 figures

\\

We invent an ac-driven quantum motor consisting of two different, interacting

ultracold atoms placed into a ring-shaped optical lattice and submerged in a

pulsating magnetic field. While the first atom carries a current, the second

one serves as a quantum starter. For fixed zero-momentum initial conditions the

asymptotic carrier velocity converges to a unique non-zero value. We also

demonstrate that this quantum motor performs work against a constant load.

\\ ( http://arxiv.org/abs/0902.0489 , 187kb)

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arXiv:0902.0463

Date: Tue, 3 Feb 2009 09:59:39 GMT (243kb)

Title: Doppler-free spectroscopy of molecular iodine using a frequency-stable

light source at 578 nm

Authors: Feng-Lei Hong, Hajime Inaba, Kazumoto Hosaka, Masami Yasuda, and

Atsushi Onae

Categories: physics.atom-ph physics.optics

Comments: 8 pages

\\

A stable light source obtained using sum-frequency generation (SFG) is

developed for high-resolution spectroscopy at 578 nm. Hyperfine transitions of

molecular iodine are observed by using the SFG light source with saturation

spectroscopy. The light source is frequency stabilized to the observed

hyperfine transition and achieves a stability of 2*10-12 for a 1-s averaging

time. The absolute frequency of the light source stabilized on the a1 component

of the R(37)16-1 transition is determined as 518304551833 (2) kHz. This

transition serves as a frequency reference for the 1S0 - 3P0 optical clock

transition in neutral ytterbium (Yb).

\\ ( http://arxiv.org/abs/0902.0463 , 243kb)

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arXiv:0902.0475

Date: Tue, 3 Feb 2009 11:00:26 GMT (2024kb)

Title: Radiofrequency multipole traps: Tools for spectroscopy and dynamics of

cold molecular ions

Authors: Roland Wester

Categories: physics.atom-ph

\\

Multipole radiofrequency ion traps are a highly versatile tool to study

molecular ions and their interactions in a well-controllable environment. In

particular the cryogenic 22-pole ion trap configuration is used to study

ion-molecule reactions and complex molecular spectroscopy at temperatures

between few Kelvin and room temperatures. This article presents a tutorial on

radiofrequency ion trapping in multipole electrode configurations. Stable

trapping conditions and buffer gas cooling, as well as important heating

mechanisms, are discussed. In addition, selected experimental studies on cation

and anion-molecule reactions and on spectroscopy of trapped ions are reviewed.

Starting from these studies an outlook on the future of multipole ion trap

research is given.

\\ ( http://arxiv.org/abs/0902.0475 , 2024kb)

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arXiv:0902.0489

Date: Tue, 3 Feb 2009 14:50:25 GMT (187kb)

Title: ac-driven atomic quantum motor

Authors: A. V. Ponomarev, S. Denisov, P. Hanggi

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

Comments: 4 pages, 4 figures

\\

We invent an ac-driven quantum motor consisting of two different, interacting

ultracold atoms placed into a ring-shaped optical lattice and submerged in a

pulsating magnetic field. While the first atom carries a current, the second

one serves as a quantum starter. For fixed zero-momentum initial conditions the

asymptotic carrier velocity converges to a unique non-zero value. We also

demonstrate that this quantum motor performs work against a constant load.

\\ ( http://arxiv.org/abs/0902.0489 , 187kb)

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arXiv:0902.0335 (*cross-listing*)

Date: Mon, 2 Feb 2009 18:47:32 GMT (237kb)

Title: Precision determination of electroweak coupling from atomic parity

violation and implications for particle physics

Authors: S. G. Porsev, K. Beloy, A. Derevianko

Categories: hep-ph physics.atom-ph

Comments: 4 pages/3 figs /1 table

\\

We carry out high-precision calculation of parity violation in cesium atom,

reducing theoretical uncertainty by a factor of two compared to previous

evaluations. We combine previous measurements with our calculations and extract

the weak charge of the 133Cs nucleus, Q_W = -73.16(29)_exp(20)_th. The result

is in agreement with the Standard Model (SM) of elementary particles. This is

the most accurate to-date test of the low-energy electroweak sector of the SM.

In combination with the results of high-energy collider experiments, we confirm

the energy-dependence (or "running") of the electroweak force over an energy

range spanning four orders of magnitude (from ~10 MeV to ~100 GeV).

Additionally, our result places constraints on a variety of new physics

scenarios beyond the SM. In particular, we increase the lower limit on the

masses of extra $Z$-bosons predicted by models of grand unification and string

theories.

\\ ( http://arxiv.org/abs/0902.0335 , 237kb)

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arXiv:0902.0696

Date: Wed, 4 Feb 2009 10:53:56 GMT (172kb)

Title: Superfluid transition in a Bose gas with correlated disorder

Authors: S. Pilati, S. Giorgini and N. Prokof'ev

Categories: cond-mat.other

Comments: 4 pages, 4 figures

\\

The superfluid transition of a three-dimensional gas of hard-sphere bosons in

a disordered medium is studied using quantum Monte Carlo methods. Simulations

are performed in continuous space both in the canonical and in the

grand-canonical ensemble. At fixed density we calculate the shift of the

transition temperature as a function of the disorder strength, while at fixed

temperature we determine both the critical chemical potential and the critical

density separating normal and superfluid phases. In the regime of strong

disorder the normal phase extends up to large values of the degeneracy

parameter and the critical chemical potential exhibits a linear dependence in

the intensity of the random potential. The role of interactions and disorder

correlations is also discussed.

\\ ( http://arxiv.org/abs/0902.0696 , 172kb)

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arXiv:0902.0739

Date: Wed, 4 Feb 2009 15:43:49 GMT (17kb,D)

Title: Biaxial nematic phases in ultracold dipolar Fermi gases

Authors: Benjamin M. Fregoso, Kai Sun, Eduardo Fradkin and Benjamin L. Lev

Categories: cond-mat.other

Comments: 4 pages, 1 figure

\\

Ultracold dipolar Fermi gases represent relatively unexplored, strongly

correlated systems arising from long-range and anisotropic interactions. We

demonstrate the possibility of a spontaneous symmetry breaking biaxial phase in

these systems, which may be realized in, e.g., gases of ultracold polar

molecules or strongly magnetic atoms. This biaxial nematic phase is manifest in

a spontaneous distortion of the Fermi surface perpendicular to the axis of

polarization. We describe these dipolar interaction induced phases using Landau

Fermi liquid theory.

\\ ( http://arxiv.org/abs/0902.0739 , 17kb)

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arXiv:0902.0611

Date: Tue, 3 Feb 2009 21:01:00 GMT (573kb)

Title: Dissipation induced coherence and stochastic resonance of an open

two-mode Bose-Einstein condensate

Authors: D. Witthaut, F. Trimborn, and S. Wimberger

Categories: quant-ph

Comments: 12 pages, 12 figures

\\

We discuss the dynamics of a Bose-Einstein condensate in a double-well trap

subject to phase noise and particle loss. The phase coherence of a

weakly-interacting condensate, experimentally measured via the contrast in an

interference experiment, as well as the response to an external driving become

maximal for a finite value of the dissipation rate matching the intrinsic time

scales of the system. This can be understood as a stochastic resonance of the

many-particle system. Even stronger effects are observed when dissipation acts

in concurrence with strong inter-particle interactions, restoring the purity of

the condensate almost completely and increasing the phase coherence

significantly. Our theoretical results are backed by Monte Carlo simulations,

which show a good qualitative agreement and provide a microscopic explanation

for the observed stochastic resonance effect.

\\ ( http://arxiv.org/abs/0902.0611 , 573kb)

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arXiv:0902.0670

Date: Wed, 4 Feb 2009 08:51:34 GMT (1026kb)

Title: Observation of continuous-wave squeezed light at 1550 nm

Authors: Moritz Mehmet, Sebastian Steinlechner, Tobias Eberle, Henning

Vahlbruch, Andr\'e Th\"uring, Karsten Danzmann, Roman Schnabel

Categories: quant-ph

Comments: 4 pages, 3 figures

\\

We report on the generation of continuous-wave squeezed vacuum states of

light at the telecommunication wavelength of 1550 nm. The squeezed vacuum

states were produced by type I optical parametric amplification (OPA) in a

standing-wave cavity built around a periodically poled potassium titanyl

phosphate (PPKTP) crystal. A non-classical noise reduction of 5.3 dB below the

shot noise was observed by means of balanced homodyne detection.

\\ ( http://arxiv.org/abs/0902.0670 , 1026kb)

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arXiv:0902.0791

Date: Wed, 4 Feb 2009 20:56:57 GMT (389kb)

Title: Stable two-dimensional solitons in nonlinear lattices

Authors: Yaroslav V. Kartashov, Boris A. Malomed, Victor A. Vysloukh, Lluis

Torner

Categories: physics.optics

Comments: 12 pages, 3 figures, to appear in Optics Letters

\\

We address the existence and stability of two-dimensional solitons in optical

or matter-wave media, which are supported by purely nonlinear lattices in the

form of a periodic array of cylinders with self-focusing nonlinearity, embedded

into a linear material. We show that such lattices can stabilize

two-dimensional solitons against collapse. We also found that stable multipoles

and vortex solitons are also supported by the nonlinear lattices, provided that

the nonlinearity exhibits saturation.

\\ ( http://arxiv.org/abs/0902.0791 , 389kb)

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arXiv:0902.0836

Date: Thu, 5 Feb 2009 03:42:43 GMT (567kb)

Title: Spectral function of spinless fermions on a one-dimensional lattice

Authors: Rodrigo G. Pereira, Steven R. White, Ian Affleck

Categories: cond-mat.str-el

Comments: 30 pages, 18 figures

\\

We study the spectral function of interacting one-dimensional fermions for an

integrable lattice model away from half-filling. The divergent power-law

singularity of the spectral function near the single-particle or single-hole

energy is described by an effective x-ray edge type model. At low densities and

for momentum near the zone boundary, we find a second divergent singularity at

higher energies which is associated with a two-particle bound state. We use the

Bethe ansatz solution of the model to calculate the exact singularity exponents

for any momentum and for arbitrary values of chemical potential and interaction

strength in the critical regime. We relate the singularities of the spectral

function to the long-time decay of the fermion Green's function and compare our

predictions with numerical results from the time-dependent density matrix

renormalization group (tDMRG). Our results show that the tDMRG method is able

to provide accurate time decay exponents in the cases of power-law decay of the

Green's function. Some implications for the line shape of the dynamical

structure factor away from half-filling are also discussed. In addition, the

spectral weight of the Luttinger liquid result for the dynamical structure

factor of the Heisenberg model at zero field is compared with the exact

two-spinon contribution.

\\ ( http://arxiv.org/abs/0902.0836 , 567kb)

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arXiv:0902.0934

Date: Thu, 5 Feb 2009 16:09:18 GMT (2083kb)

Title: Interaction of dark-bright solitons in two-component Bose-Einstein

condensates

Authors: S. Rajendran, P. Muruganandam, M. Lakshmanan

Categories: cond-mat.other nlin.PS

Comments: 5 pages, 5 figures

\\

We study the interaction of dark-bright solitons in two component

Bose-Einstein condensates by suitably tailoring the trap potential, atomic

scattering length and atom gain or loss. We show that the coupled

Gross-Pitaevskii (GP) equation can be mapped onto the Manakov model. An

interesting class of matter wave solitons and their interaction are identified

with confining as well as expulsive trap potentials, which can be

experimentally realized in two component condensates.

\\ ( http://arxiv.org/abs/0902.0934 , 2083kb)

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arXiv:0902.0881

Date: Thu, 5 Feb 2009 11:01:05 GMT (103kb)

Title: Reversible state transfer between superconducting qubits and atomic

ensembles

Authors: D. Petrosyan, G. Bensky, G. Kurizki, I. Mazets, J. Majer, J.

Schmiedmayer

Categories: quant-ph

\\

We examine the possibility of coherent, reversible information transfer

between solid-state superconducting qubits and ensembles of ultra-cold atoms.

Strong coupling between these systems is mediated by a microwave transmission

line resonator that interacts near-resonantly with the atoms via their

optically excited Rydberg states. The solid-state qubits can then be used to

implement rapid quantum logic gates, while collective metastable states of the

atoms can be employed for long-term storage and optical read-out of quantum

information.

\\ ( http://arxiv.org/abs/0902.0881 , 103kb)

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The replacements:

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arXiv:0810.5703

replaced with revised version Fri, 30 Jan 2009 08:19:19 GMT (2150kb)

Title: Stimulating the production of deeply bound RbCs molecules with laser

pulses: the role of spin-orbit coupling in forming ultracold molecules

Authors: Subhas Ghosal, Richard J. Doyle, Christiane P. Koch and Jeremy M.

Hutson

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

\\ ( http://arxiv.org/abs/0810.5703 , 2150kb)

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arXiv:0807.2898

replaced with revised version Sun, 1 Feb 2009 01:06:25 GMT (166kb)

Title: Heavily Damped Motion of One-Dimensional Bose Gases in an Optical

Lattice

Authors: Ippei Danshita, Charles W. Clark

Categories: cond-mat.other

Comments: 4 pages, 5 figures, published version

Journal-ref: Phys. Rev. Lett. 102, 030407 (2009)

\\ ( http://arxiv.org/abs/0807.2898 , 166kb)

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arXiv:0807.4534

replaced with revised version Mon, 2 Feb 2009 11:54:45 GMT (55kb)

Title: Unconventional quantum phases of lattice bosonic mixtures

Authors: P. Buonsante, S. M. Giampaolo, F. Illuminati, V. Penna, A. Vezzani

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

Comments: 10 pages, 2 figures - to appear in the topical issue on "Novel

Quantum Phases and Mesoscopic Physics in Quantum Gases" of the European

Physical Journal B (2009)

\\ ( http://arxiv.org/abs/0807.4534 , 55kb)

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arXiv:0812.2701

replaced with revised version Sat, 31 Jan 2009 22:18:11 GMT (1221kb,D)

Title: Electro-Optical Nanotraps for Neutral Atoms

Authors: Brian Murphy and Lene Vestergaard Hau

Categories: physics.atom-ph cond-mat.mes-hall hep-ph physics.optics quant-ph

Comments: 5 pages, 3 figures. Fig. 1 appeared on the cover of the January 23,

2009 issue of PRL

Journal-ref: Phys. Rev. Lett. 102, 033003 (2009)

DOI: 10.1103/PhysRevLett.102.033003

\\ ( http://arxiv.org/abs/0812.2701 , 1221kb)

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arXiv:0811.3961

replaced with revised version Tue, 3 Feb 2009 10:30:20 GMT (1110kb,D)

Title: Practical scheme for a light-induced gauge field in an atomic Bose gas

Authors: Kenneth J. G\"unter, Marc Cheneau, Tarik Yefsah, Steffen P. Rath, and

Jean Dalibard

Categories: cond-mat.str-el cond-mat.mes-hall quant-ph

Comments: 4 pages, 3 figures

Journal-ref: Phys. Rev. A 79, 011604(R) (2009)

DOI: 10.1103/PhysRevA.79.011604

\\ ( http://arxiv.org/abs/0811.3961 , 1110kb)

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arXiv:0809.1539

replaced with revised version Wed, 4 Feb 2009 09:57:35 GMT (671kb)

Title: Pair correlations of a spin-imbalanced Fermi gas on two-leg ladders

Authors: A. E. Feiguin and F. Heidrich-Meisner

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

Comments: To appear in Phys. Rev. Lett.; minor revisions

\\ ( http://arxiv.org/abs/0809.1539 , 671kb)

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arXiv:0901.4631

replaced with revised version Wed, 4 Feb 2009 10:25:24 GMT (393kb)

Title: From Bogoliubov's approximation to Popov's hydrodynamic theory: a

unified picture of superfluidity

Authors: N. Dupuis

Categories: cond-mat.other

Comments: v2) 4 pages, 4 figures

\\ ( http://arxiv.org/abs/0901.4631 , 393kb)

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arXiv:quant-ph/0701167

replaced with revised version Wed, 4 Feb 2009 12:27:37 GMT (636kb)

Title: Cold Atom Physics Using Ultra-Thin Optical Fibers: Light-Induced Dipole

Forces and Surface Interactions

Authors: G. Sagu\'e, E. Vetsch, W. Alt, D. Meschede and A. Rauschenbeutel

Categories: quant-ph

Comments: 4 pages, 4 figures

Journal-ref: PRL 99, 163602 (2007)

\\ ( http://arxiv.org/abs/quant-ph/0701167 , 636kb)

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arXiv:0808.3620

replaced with revised version Wed, 4 Feb 2009 15:00:04 GMT (1051kb)

Title: Observation of Cold Collisions between Trapped Ions and Trapped Atoms

Authors: Andrew T. Grier, Marko Cetina, Fedja Oru\v{c}evi\'c, Vladan Vuleti\'c

Categories: physics.atom-ph

Comments: 4 pages, 4 figures; Revision 1/V2: Revised in response to PRL

Referees' comments

\\ ( http://arxiv.org/abs/0808.3620 , 1051kb)

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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 =========================================================================Received on Fri May 01 2009 - 15:51:04 EST

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