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

Date: Thu, 30 Nov 2006 09:49:53 +1000 (EST)

Date: Thu, 30 Nov 2006 09:49:53 +1000 (EST)

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

Hi all,

Slightly late again this week. Next week's should be slightly early.

Only 23 new papers this time. I heard a slightly amusing story from one of our

graduate students a few days ago: when he started his PhD earlier this year he

thought that he should be reading *every* paper in the weekly arXiv seletion.

He started to get a bit stressed when he was only getting through three or four

and trying to do some work as well. Thankfully someone put him straight before

he decided to quit!

On with the abstracts:

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Paper: cond-mat/0611446

Date: Thu, 16 Nov 2006 21:59:52 GMT (225kb)

Title: Minority Spin Condensate in Spin-Polarized Superfluid $^3$He-A$_1$ Phase

Authors: A. Yamaguchi, S. Kobayashi, H. Ishimoto and H. Kojima

Comments: 13 pages, 4 figures. Accepted for publication in Nature

Subj-class: Other

\\

The spin-polarized superfluid $^3$He A$_1$ phase, which forms below 3 mK in

external magnetic field, serves as a material in which theoretical notions of

fundamental magnetic processes and macroscopic quantum spin phenomena may be

tested. Conventionally, the superfluid component of the A$_1$ phase is

understood to contain only the majority spin condensate having

energetically-favoured paired spins directed along the external field and no

minority spin condensate having paired spins in the opposite direction. We have

developed a novel mechanical spin density detector to measure the spin

relaxation in the A$_1$ phase as functions of temperature, pressure and

magnetic field. The mechanical spin detector is based in principle on the

unique magnetic fountain effect occurring only in the A$_1$ phase (occurring

between two transition temperatures, T$_{c1}$ and T$_{c2}$). Unexpectedly, the

spin relaxation rate increases rapidly as the temperature is decreased towards

T$_{c2}$. Our measurements, together with Leggett-Takagi and Monien-Tewordt

theories, demonstrate that a minute presence of minority spin pairs is

responsible for the unexpected spin relaxation phenomena in A$_1$ phase.

\\ ( http://arXiv.org/abs/cond-mat/0611446 , 225kb)

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Paper: cond-mat/0611450

Date: Fri, 17 Nov 2006 06:07:59 GMT (15kb)

Title: Bethe Ansatz for 1D interacting anyons

Authors: M.T. Batchelor, X.-W. Guan and J.-S. He

Comments: 22 pages

Subj-class: Statistical Mechanics

\\

This article gives a pedagogic derivation of the Bethe Ansatz solution for 1D

interacting anyons. This includes a demonstration of the subtle role of the

anyonic phases in the Bethe Ansatz arising from the anyonic commutation

relations. The thermodynamic Bethe Ansatz equations defining the temperature

dependent properties of the model are also derived, from which some groundstate

properties are obtained.

\\ ( http://arXiv.org/abs/cond-mat/0611450 , 15kb)

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Paper: cond-mat/0611456

Date: Fri, 17 Nov 2006 10:44:49 GMT (521kb)

Title: Mean field theory and fluctuation spectrum of a pumped, decaying

Bose-Fermi system across the quantum condensation transition

Authors: M. H. Szymanska, J. Keeling, P. B. Littlewood

Comments: 28 pages, 11 figures

Subj-class: Other

\\

We study the mean-field theory, and the properties of fluctuations, in an out

of equilibrium Bose-Fermi system, across the transition to a quantum condensed

phase. The system is driven out of equilibrium by coupling to multiple baths,

which are not in equilibrium with each other, and thus drive a flux of

particles through the system.

We derive the self-consistency condition for an uniform condensed steady

state. This condition can be compared both to the laser rate equation and to

the Gross-Pitaevskii equation of an equilibrium condensate. We study

fluctuations about the steady state, and discuss how the multiple baths

interact to set the system's distribution function. In the condensed system,

there is a soft phase (Bogoliubov, Goldstone) mode, diffusive at small momenta

due to the presence of pump and decay, and we discuss how one may determine the

field-field correlation functions properly including such soft phase modes. In

the infinite system, the correlation functions differ both from the laser and

from an equilibrium condensate; we discuss how in a finite system, the laser

limit may be recovered.

\\ ( http://arXiv.org/abs/cond-mat/0611456 , 521kb)

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Paper: quant-ph/0611181

Date: Thu, 16 Nov 2006 23:00:27 GMT (154kb)

Title: Adiabatic frequency conversion of quantum optical information in atomic

vapor

Authors: Frank Vewinger, Juergen Appel, Eden Figueroa, A. I. Lvovsky

\\

We experimentally demonstrate a quantum communication protocol that enables

frequency conversion and routing of quantum optical information in an adiabatic

and thus robust way. The protocol is based on electromagnetically-induced

transparency in systems with multiple excited levels: transfer and/or

distribution of optical states between different signal modes is implemented by

adiabatically changing the control fields. The proof-of-principle experiment is

performed using the hyperfine levels of the rubidium D1 line.

\\ ( http://arXiv.org/abs/quant-ph/0611181 , 154kb)

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Paper: quant-ph/0611185

Date: Fri, 17 Nov 2006 10:20:15 GMT (116kb)

Title: Test of the isotopic and velocity selectivity of a lithium atom

interferometer by magnetic dephasing

Authors: Marion Jacquey (LCAR), Alain Miffre (LCAR, LASIM), Matthias

B\"{u}chner (LCAR), G\'{e}rard Tr\'{e}nec (LCAR), Jacques Vigu\'{e} (LCAR)

Proxy: ccsd hal-00114617

\\

A magnetic field gradient applied to an atom interferometer induces a

$M$-dependent phase shift which results in a series of decays and revivals of

the fringe visibility. Using our lithium atom interferometer based on Bragg

laser diffraction, we have measured the fringe visibility as a function of the

applied gradient. We have thus tested the isotopic selectivity of the

interferometer, the velocity selective character of Bragg diffraction for

different diffraction orders as well as the effect of optical pumping of the

incoming atoms. All these observations are qualitatively understood but a

quantitative analysis requires a complete model of the interferometer.

\\ ( http://arXiv.org/abs/quant-ph/0611185 , 116kb)

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Paper: physics/0611175

Date: Fri, 17 Nov 2006 20:03:34 GMT (745kb)

Title: Light forces in ultracold photoassociation

Authors: E. Gomez (1), A. T. Black (1), L. D. Turner (1), E. Tiesinga (1), P.

D. Lett (1), ((1)National Institute of Standards and Technology,

Gaithersburg)

Comments: 7 pages, 3 figures

Subj-class: Atomic Physics

\\

We study the time-resolved photoassociation of ultracold sodium in an optical

dipole trap. The photoassociation laser excites pairs of atoms to molecular

states of large total angular momentum at high intensities (above 20

kW/cm$^{2}$). Such transitions are generally suppressed at ultracold

temperatures by the centrifugal barriers for high partial waves. Time-resolved

ionization measurements reveal that the atoms are accelerated by the dipole

potential of the photoassociation beam. We change the collision energy by

varying the potential depth, and observe a strong variation of the

photoassociation rate. These results demonstrate the important role of light

forces in cw photoassociation at high intensities.

\\ ( http://arXiv.org/abs/physics/0611175 , 745kb)

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Paper: cond-mat/0611421

Date: Thu, 16 Nov 2006 02:53:26 GMT (51kb)

Title: Pairing in Asymmetrical Fermi Systems with Intra- and Inter-Species

Correlations

Authors: Renyuan Liao and Khandker F. Quader (Dept of Physics, Kent State

University)

Comments: 5 pages, 3 figures

Subj-class: Superconductivity; Strongly Correlated Electrons; Atomic Physics

\\

We consider inter- and intra-species pairing interactions in an asymmetrical

Fermi system. Using equation of motion method, we obtain coupled mean-field

equations for superfluid gap functions and population densities. We construct a

phase diagram across BCS-BEC regimes. Due to intra-species correlations, the

BCS singlet superfluid state can sustain finite polarizations, $P$. For larger

$P$, we find phase separations in BCS and BEC regimes. A superfluid phase

exists for all $P$ deep in BEC regime. Our results may apply to pairing in

ultracold fermions, nuclear and quark matter physics.

\\ ( http://arXiv.org/abs/cond-mat/0611421 , 51kb)

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Paper: cond-mat/0611479

Date: Fri, 17 Nov 2006 21:38:06 GMT (40kb)

Title: Competition between local potentials and attractive particle-particle

interactions in superlattices

Authors: N. A. Lima, A. L. Malvezzi and K. Capelle

Comments: 8 pages, 2 figures

Subj-class: Strongly Correlated Electrons; Materials Science

\\

Naturally occuring or man-made systems displaying periodic spatial

modulations of their properties on a nanoscale constitute superlattices. Such

modulated structures are important both as prototypes of simple

nanotechnological devices and as particular examples of emerging spatial

inhomogeneity in interacting many-electron systems. Here we investigate the

effect different types of modulation of the system parameters have on the

ground-state energy and the charge-density distribution of the system. The

superlattices are described by the inhomogeneous attractive Hubbard model, and

the calculations are performed by density-functional and density-matrix

renormalization group techniques. We find that modulations in local electric

potentials are much more effective in shaping the system's properties than

modulations in the attractive on-site interaction. This is the same conclusions

we previously (Phys. Rev. B 71, 125130) obtained for repulsive interactions,

suggesting that it is not an artifact of a specific state, but a general

property of modulated structures.

\\ ( http://arXiv.org/abs/cond-mat/0611479 , 40kb)

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Paper: cond-mat/0611487

Date: Sat, 18 Nov 2006 12:11:08 GMT (454kb)

Title: Time modulation of atom sources

Authors: A. del Campo, J. G. Muga, M. Moshinsky

Comments: 13 pages, 8 figures

Subj-class: Other

\\

Sudden turn-on of a matter-wave source leads to characteristic oscillations

of the probability density which are the hallmark feature of diffraction in

time. The apodization of matter waves relies on the use of smooth aperture

functions which suppress such oscillations. The analytical dynamics arising

with different aperture functions are discussed systematically for switching-on

processes, and for single and many-pulse formation procedures. The possibility

and time scale of a revival of the diffraction-in-time pattern is also

analysed. Similar modulations in time of the pulsed output coupling in

atom-lasers are responsible for the dynamical evolution and characteristics of

the beam profile. For multiple pulses, different phase schemes and regimes are

described and compared. Strongly overlapping pulses lead to a saturated,

constant beam profile in time and space, up to the revival phenomenon.

\\ ( http://arXiv.org/abs/cond-mat/0611487 , 454kb)

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Paper: cond-mat/0611490

Date: Sat, 18 Nov 2006 14:07:52 GMT (11kb)

Title: Static Properties of Trapped Bose Gases at Finite Temperature: I.

Thomas- Fermi Limit

Authors: Benarous Mohamed and Houria Chachou Samet

Comments: 11 pages

Subj-class: Statistical Mechanics

\\

We rely on a time-dependent variational approach to derive the dynamics of a

trapped self-interacting Bose gas at finite temperature. We then analyze the

static situation both at zero and finite temperature in the Thomas-Fermi limit.

We derive analytic expressions for the condensate radius and the chemical

potential at finite temperature and obtain encouraging results for the various

density profiles. A novel image of the way the condensed and non condensed

phases mix up emerges from our calculations.

\\ ( http://arXiv.org/abs/cond-mat/0611490 , 11kb)

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Paper: cond-mat/0611506

Date: Sun, 19 Nov 2006 21:00:22 GMT (13kb)

Title: Schrodinger equation for the one particle density matrix of thermal

systems: An alternative formulation of Bose-Einstein condensation

Authors: Subodha Mishra and Peter Pfeifer

Comments: 4 pages, 2 figures

Subj-class: Statistical Mechanics

\\

We formulate a linear Schrodinger equation with the temperature-dependent

potential for the one-particle density matrix and obtain the condensation

temperature of the Bose-Einstein condensate from a bound-state condition for

the Schrodinger equation both with and without the confining trap. The results

are in very good agreement with those of the full statistical physics

treatment. This is an alternative to the Bose-Einstein condensation in the

standard ideal Bose gas treatment.

\\ ( http://arXiv.org/abs/cond-mat/0611506 , 13kb)

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Paper: cond-mat/0611510

Date: Mon, 20 Nov 2006 06:34:36 GMT (669kb)

Title: Ground-state properties of the attractive one-dimensional Bose-Hubbard

model

Authors: Norman Oelkers and Jon Links

Comments: 17 pages, 12 figures

Subj-class: Statistical Mechanics

\\

We study the ground state of the attractive one-dimensional Bose-Hubbard

model, and in particular the nature of the crossover between the weak

interaction and strong interaction regimes for finite system sizes. Indicator

properties like the gap between the ground and first excited energy levels, and

the incremental ground-state wavefunction overlaps are used to locate

transitions. Using mean-field theory, we show there are two distinct

transitions connected to spontaneous symmetry breaking of the ground state. The

first transition arises in an analysis valid for large L with finite N, where L

is the number of lattice sites and N is the total particle number. An

alternative approach valid for large N with finite L yields a second

transition. For small system sizes we numerically investigate the model, and

observe that there are signatures of both transitions. We compare with exact

results from Bethe ansatz methods in several limiting cases to explore the

validity for these numerical and mean-field schemes. The results indicate that

for finite attractive systems there are generically three ground-state phases

of the model.

\\ ( http://arXiv.org/abs/cond-mat/0611510 , 669kb)

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Paper: cond-mat/0611512

Date: Mon, 20 Nov 2006 07:21:32 GMT (634kb)

Title: A class of permanent magnetic lattices for ultracold atoms

Authors: Saeed Ghanbari, Tien D Kieu and Peter Hannaford

Comments: 18 pages

Subj-class: Other

\\

We report on a class of configurations of permanent magnets on an atom chip

for producing 1D and 2D periodic arrays of magnetic microtraps with non-zero

potential minima and variable barrier height for trapping and manipulating

ultracold atoms and quantum degenerate gases. We present analytical expressions

for the relevant physical quantities and compare them with our numerical

results and with some previous numerical calculations. In one of the

configurations of permanent magnets, we show how it is possible by changing the

angle between the crossed periodic arrays of magnets to go from a 1D array of

2D microtraps to a 2D array of 3D microtraps and thus to continuously vary the

barrier heights between the microtraps. This suggests the possibility of

performing a type of `mechanical' BEC to Mott insulator quantum phase

transition in a magnetic lattice. We also discuss a configuration of magnets

which could realize a two-qubit quantum gate in a magnetic lattice.

\\ ( http://arXiv.org/abs/cond-mat/0611512 , 635kb)

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Paper: cond-mat/0611522

Date: Mon, 20 Nov 2006 14:08:00 GMT (214kb)

Title: Variational study of hard-core bosons in a 2-D optical lattice using

Projected Entangled Pair States (PEPS)

Authors: V. Murg, F. Verstraete, J. I. Cirac

Comments: 9 pages, 9 figures

Subj-class: Other

\\

We have studied the system of hard-core bosons on a 2-D optical lattice using

a variational algorithm based on projected entangled-pair states (PEPS). We

have investigated the ground state properties of the system as well as the

responses of the system to sudden changes in the parameters. We have compared

our results to mean field results based on a Gutzwiller ansatz.

\\ ( http://arXiv.org/abs/cond-mat/0611522 , 214kb)

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Paper (*cross-listing*): gr-qc/0611096

Date: Fri, 17 Nov 2006 16:34:37 GMT (9kb)

Title: Analog Models beyond Kinematics

Authors: Serena Fagnocchi

Comments: 8 pages; Talk given at ISSP (Erice, September 2006); to appear on

World Scientific

Subj-class: General Relativity and Quantum Cosmology; Other

\\

In this paper I discuss the extension of the analogy between gravitation and

some systems of condensed matter physics from kinematics to dynamics. I will

focus my attention on two applications of the analogy to the dynamics of fluids

that have been recently proposed: the study of backreaction effects and the

calculation of the depletion in Bose-Einstein condensates, showing how this

extension is possible and stressing the main differences with respect to the

gravitational context. I will conclude with some remarks about the actual

reliability of the proposed scheme, pointing out the basis issues that have

still to be addressed.

\\ ( http://arXiv.org/abs/gr-qc/0611096 , 9kb)

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Paper (*cross-listing*): nucl-th/0611064

Date: Fri, 17 Nov 2006 07:11:09 GMT (60kb)

Title: Indication of BCS-BEC crossover behavior in halo nuclei

Authors: K. Hagino, H. Sagawa, J. Carbonell, and P. Schuck

Comments: 4 pages, 3 eps figures

Subj-class: Nuclear Theory; Superconductivity

\\

We investigate the spatial structure of two-neutron wave function in a

Borromean nucleus $^{11}$Li using a three-body model in which two valence

neutrons interact with each other by a density-dependent contact force. The

behavior of the neutron Cooper pair at different densities is simulated by

calculating the two-neutron wave function at several distances between the core

nucleus and the center of mass of the two neutrons. We find that the neutron

pair wave function in $^{11}$Li has an oscillation at normal density, while it

becomes a well localized single peak in the dilute density region around the

nuclear surface.

These features are in close analogue to the BCS-BEC crossover of the Cooper

pair wave function found in the infinite nuclear matter. The present results

also provide a unified picture of the di-neutron and the cigar-like

configurations in Borromian nuclei as a manifestation of the BCS-BEC crossover

phenomenon.

\\ ( http://arXiv.org/abs/nucl-th/0611064 , 60kb)

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Paper: quant-ph/0611190

Date: Sat, 18 Nov 2006 01:03:21 GMT (13kb)

Title: Precision measurement with an optical Josephson junction

Authors: H. T. Ng, K. Burnett and J. A. Dunningham

Comments: 6 pages, 1 figure

\\

We study a new type of Josephson device, the so-called ``optical Josephson

junction'' as proposed in Phys. Rev. Lett. {\bf 95}, 170402 (2005). Two

condensates are optically coupled through a waveguide by a pair of Bragg beams.

This optical Josephson junction is analogous to the usual Josephson junction of

two condensates weakly coupled via tunneling. We discuss the use of this

optical Josephson junction, for making precision measurements.

\\ ( http://arXiv.org/abs/quant-ph/0611190 , 13kb)

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Paper: quant-ph/0611204

Date: Mon, 20 Nov 2006 02:57:13 GMT (390kb)

Title: Squeezed light for bandwidth limited atom optics experiments at the

Rubidium D1 line

Authors: G. H\'etet, O. Gl\"ockl, K. A. Pilypas, C.C. Harb, B.C. Buchler, H.-A.

Bachor, P.K. Lam

Comments: 8 pages, 3 figures. Accepted for Journal of Physics B

\\

We report on the generation of more than 5 dB of vacuum squeezed light at the

Rubidium D1 line (795 nm) using periodically poled KTiOPO$_{4}$ (PPKTP) in an

optical parametric oscillator. We demonstrate squeezing at low sideband

frequencies, making this source of non-classical light compatible with

bandwidth limited atom optics experiments. When PPKTP is operated as a

parametric amplifier, we show a noise reduction of 4 dB stably locked within

the 150 kHz-500 kHz frequency range. This matches the bandwidth of

Electromagnetically Induced Transparency (EIT) in Rubidium hot vapour cells

under the condition of large information delay.

\\ ( http://arXiv.org/abs/quant-ph/0611204 , 390kb)

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Paper: cond-mat/0611561

Date: Tue, 21 Nov 2006 16:24:50 GMT (887kb)

Title: Free fermion antibunching in a degenerate atomic Fermi gas released from

an optical lattice

Authors: T. Rom, Th. Best, D. van Oosten, U. Schneider, S. Foelling, B. Paredes

and I. Bloch

Comments: (Nature, in press)

Subj-class: Other

\\

Noise in a quantum system is fundamentally governed by the statistics and the

many-body state of the underlying particles. Whereas for bosonic particles the

correlated noise observed for e.g. photons or bosonic neutral atoms can still

be explained within a classical field description with fluctuating phases, the

anticorrelations in the detection of fermionic particles have no classical

analogue. The observation of such fermionic antibunching is so far scarce and

has been confined to electrons and neutrons. Here we report on the first direct

observation of antibunching of neutral fermionic atoms. Through an analysis of

the atomic shot noise in a set of standard absorption images, of a gas of

fermionic 40K atoms released from an optical lattice, we find reduced

correlations for distances related to the original spacing of the trapped

atoms. The detection of such quantum statistical correlations has allowed us to

characterise the ordering and temperature of the Fermi gas in the lattice.

Moreover, our findings are an important step towards revealing fundamental

fermionic many-body quantum phases in periodic potentials, which are at the

focus of current research.

\\ ( http://arXiv.org/abs/cond-mat/0611561 , 887kb)

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Paper: cond-mat/0611566

Date: Tue, 21 Nov 2006 19:13:48 GMT (47kb)

Title: Measurement of the Entropy and Critical Temperature of a Strongly

Interacting Fermi Gas

Authors: L. Luo, B. Clancy, J. Joseph, J. Kinast, and J. E. Thomas

Comments: 16 pages, 3 figures

Subj-class: Other

\\

We report a model-independent measurement of the entropy, energy, and

critical temperature of a degenerate, strongly interacting Fermi gas of atoms.

The total energy is determined from the mean square cloud size in the strongly

interacting regime, where the gas exhibits universal behavior. The entropy is

measured by sweeping a bias magnetic field to adiabatically tune the gas from

the strongly interacting regime to a weakly interacting regime, where the

entropy is known from the cloud size after the sweep. The dependence of the

entropy on the total energy quantitatively tests predictions of the

finite-temperature thermodynamics.

\\ ( http://arXiv.org/abs/cond-mat/0611566 , 47kb)

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Paper (*cross-listing*): math-ph/0611043

Date: Fri, 17 Nov 2006 20:40:28 GMT (18kb)

Title: Interacting Bose and Fermi gases in low dimensions and the Riemann

hypothesis

Authors: Andr\'e LeClair

Subj-class: Mathematical Physics; Statistical Mechanics; Number Theory

\\

We apply the S-matrix based finite temperature formalism we recently

developed to non-relativistic Bose and Fermi gases in 1+1 and 2+1 dimensions.

In the 2+1 dimensional case, the free energy is given in terms of Roger's

dilogarithm in a way analagous to the relativistic 1+1 dimensional case. The 1d

fermionic case with a quasi-periodic 2-body potential provides a physical

framework for understanding the Riemann hypothesis.

\\ ( http://arXiv.org/abs/math-ph/0611043 , 18kb)

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Paper: quant-ph/0611219

Date: Tue, 21 Nov 2006 18:28:01 GMT (27kb)

Title: On experimental procedures for entanglement verification

Authors: S.J. van Enk, N. Lutkenhaus, and H.J. Kimble

Comments: 14 pages

\\

We give an overview of different types of entanglement that can be generated

in experiments, as well as of various protocols that can be used to verify or

quantify entanglement. We propose several criteria that, we argue, ought to be

applied to experimental entanglement verification procedures. Explicit examples

demonstrate that not following these criteria will tend to result in

overestimating the amount of entanglement generated in an experiment or in

infering entanglement when there is none. We distinguish protocols meant to

refute or eliminate hidden-variable models from those meant to verify

entanglement.

\\ ( http://arXiv.org/abs/quant-ph/0611219 , 27kb)

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Paper: cond-mat/0611578

Date: Wed, 22 Nov 2006 09:32:03 GMT (66kb)

Title: Trapped Resonant Fermions above Superfluid Transition Temperature

Authors: Chi-Ho Cheng and Sung-Kit Yip

Comments: 9 pages, 4 figures

Subj-class: Superconductivity; Other

\\

We investigate trapped resonant fermions with unequal populations within the

local density approximation above the superfluid transition temperature. By

tuning the attractive interaction between fermions via Feshbach resonance, the

system evolves from weakly interacting fermi gas to strongly interacting fermi

gas, and finally becomes bose-fermi mixture. The density profiles of fermions

are examined and compared with experiments. We also point out the simple

relationships between the local density, the axial density, and the gas

pressure within the local density approximation.

\\ ( http://arXiv.org/abs/cond-mat/0611578 , 66kb)

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Paper: cond-mat/0611584

Date: Wed, 22 Nov 2006 13:14:07 GMT (67kb)

Title: Momentum distribution dynamics of a Tonks-Girardeau gas: Bragg

reflections of a quantum many-body wavepacket

Authors: R. Pezer and H. Buljan

Subj-class: Other

\\

The dynamics of the momentum distribution and the reduced single-particle

density matrix (RSPDM) of a Tonks-Girardeau (TG) gas is studied in the context

of Bragg-reflections of a many-body wavepacket. We find strong suppression of a

Bragg-reflection peak for a dense TG wavepacket; our observation illustrates

dependence of the momentum distribution on the interactions/wavefunction

symmetry. The momentum distribution is calculated with a fast algorithm based

on a formula expressing the RSPDM via a dynamically evolving single-particle

basis.

\\ ( http://arXiv.org/abs/cond-mat/0611584 , 67kb)

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Paper: quant-ph/0611221

Date: Tue, 21 Nov 2006 22:26:45 GMT (714kb)

Title: Self ordering and superradiant backscattering of a gaseous beam in a

ring cavity with counter propagating pump

Authors: C. Maes, J. Asboth, H. Ritsch

Comments: 18 pages 11 figures

\\

We study the threshold conditions of spatial self organization combined with

collective coherent optical backscattering of a thermal gaseous beam moving in

a high Q ring cavity with counter propagating pump. We restrict ourselves to

the limit of large detuning between the particles optical resonances and the

light field, where spontaneous emission is negligible and the particles can be

treated as polarizable point masses. Using a linear stability analysis in the

accelerated rest frame of the particles we derive an analytic bounds for the

selforganization as a function of particle number,average velocity, temperature

and resonator parameters. We check our results by a numerical iteration

procedure as well as by direct simulations of the N-particle dynamics. Due to

momentum conservation the backscattered intensity determines the average force

on the cloud, which gives the conditions for stopping and cooling a fast

molecular beam.

\\ ( http://arXiv.org/abs/quant-ph/0611221 , 714kb)

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Paper: quant-ph/0611228

Date: Wed, 22 Nov 2006 12:14:44 GMT (292kb)

Title: Spectral theory of quantum memory and entanglement via Raman scattering

of light by an atomic ensemble

Authors: O.S. Mishina, D.V. Kupriyanov, J.H. Muller, E.S. Polzik

Comments: 14 pages, 6 figures. submitted to PRA

\\

We discuss theoretically quantum interface between light and a spin polarized

ensemble of atoms with the spin $\geq 1$ based on an off-resonant Raman

scattering. We present the spectral theory of the light-atoms interaction and

show how particular spectral modes of quantum light couple to spatial modes of

the extended atomic ensemble. We show how this interaction can be used for

quantum memory storage and retrieval and for deterministic entanglement

protocols. The proposed protocols are attractive due to their simplicity since

they involve just a single pass of light through atoms without the need for

elaborate pulse shaping or quantum feedback. As a practically relevant example

we consider the interaction of a light pulse with hyperfine components of D-1

line of 87Rb. The quality of the proposed protocols is verified via analytical

and numerical analysis.

\\ ( http://arXiv.org/abs/quant-ph/0611228 , 292kb)

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The replacements: apologies to Dr A.P. Itin, when I missed one of his replaced

manuscripts last week.

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Missed last week:

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Paper: cond-mat/0610767

replaced with revised version Tue, 14 Nov 2006 06:56:47 GMT

Title: Universality in nonadiabatic behaviour of classical actions in

nonlinear models with separatrix crossings

Authors: A.P. Itin, S. Watanabe

Comments: 17 pages, 11 figures Comment to ver. 2: some typos and notations

in figures are corrected

Subj-class: Other

\\ ( http://arxiv.org/abs/cond-mat/0610767 )

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Paper: cond-mat/0602224

replaced with revised version Fri, 17 Nov 2006 00:56:12 GMT (107kb)

Title: Critical Temperature and Thermodynamics of Attractive Fermions at

Unitarity

Authors: Evgeni Burovski, Nikolay Prokof'ev, Boris Svistunov, and Matthias

Troyer

Comments: 4+1 pages, 4 figures, published version + erratum

Subj-class: Statistical Mechanics; Superconductivity

Journal-ref: Phys. Rev. Lett. 96, 160402 (2006)

DOI: 10.1103/PhysRevLett.96.160402

\\ ( http://arXiv.org/abs/cond-mat/0602224 , 107kb)

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Paper: cond-mat/0406454

replaced with revised version Mon, 20 Nov 2006 03:22:53 GMT (606kb)

Title: Vortex Dynamics Near the Surface of a Bose-Einstein Condensate

Authors: U. Al Khawaja

Comments: 8 pages, 9 figures

Subj-class: Statistical Mechanics

Journal-ref: Phys. Rev. A 71, 063611 (2005)

\\ ( http://arXiv.org/abs/cond-mat/0406454 , 606kb)

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Paper: cond-mat/0603479

replaced with revised version Mon, 20 Nov 2006 13:42:17 GMT (8kb)

Title: Ground state energy density of a dilute Bose gas in the canonical

transformation

Authors: Hyun Sik Noh, Sang-Hoon Kim, Chul Koo Kim, and Mukunda P. Das

Comments: 5 pages, 0 figure

Subj-class: Statistical Mechanics

\\ ( http://arXiv.org/abs/cond-mat/0603479 , 8kb)

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Paper: cond-mat/0607618

replaced with revised version Mon, 20 Nov 2006 16:48:08 GMT (65kb)

Title: Single-particle versus pair condensation of hard-core bosons with

correlated hopping

Authors: K.P. Schmidt, J. Dorier, A. Laeuchli, and F. Mila

Comments: 8 pages, 7 figures

Subj-class: Other

Journal-ref: Phys. Rev. B 74, 174508 (2006)

DOI: 10.1103/PhysRevB.74.174508

\\ ( http://arXiv.org/abs/cond-mat/0607618 , 65kb)

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Paper: cond-mat/0608690

replaced with revised version Sun, 19 Nov 2006 02:14:25 GMT (95kb)

Title: Hidden symmetry and quantum phases in spin-3/2 cold atomic systems

Authors: Congjun Wu

Subj-class: Strongly Correlated Electrons

\\ ( http://arXiv.org/abs/cond-mat/0608690 , 95kb)

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Paper: cond-mat/0610367

replaced with revised version Wed, 22 Nov 2006 13:19:42 GMT (9kb)

Title: The depletion in Bose Einstein condensates using Quantum Field Theory in

curved space

Authors: Roberto Balbinot, Serena Fagnocchi, Alessandro Fabbri

Comments: 4 pages, no figure. Typos corrected

Subj-class: Other; Soft Condensed Matter

\\ ( http://arXiv.org/abs/cond-mat/0610367 , 9kb)

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Paper: quant-ph/0610114

replaced with revised version Tue, 21 Nov 2006 21:55:21 GMT (139kb)

Title: Rotation of atoms in a two dimensional lattice with a harmonic trap

Authors: T. Wang, S. Yelin

Comments: 4 pages, some paragraphs were refrased, typos corrected

\\ ( http://arXiv.org/abs/quant-ph/0610114 , 139kb)

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Till next week,

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 Nov 30 2006 - 09:49:53 EST

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