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

Date: Fri, 29 Feb 2008 21:38:15 +1000

Date: Fri, 29 Feb 2008 21:38:15 +1000

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

Hi everyone,

It's been grant deadlines and back to teaching this week, so Matt's arXiv is a

Friday night special. We have 23 new preprints and 12 replacements:

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arXiv:0802.2101

Date: Thu, 14 Feb 2008 22:23:04 GMT (150kb,D)

Title: Stability of Superflow for Ultracold Fermions in Optical Lattices

Authors: A.A. Burkov, Arun Paramekanti

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

Comments: 4+ pages, 2 figures

\\

Motivated by recent observations of superfluidity of ultracold fermions in

optical lattices, we investigate the stability of superfluid flow of paired

fermions in the lowest band of a strong optical lattice. For fillings close to

one fermion per site, we show that superflow breaks down via a dynamical

instability leading to a transient density wave. At lower fillings, there is a

distinct dynamical instability, where the superfluid stiffness becomes

negative; this evolves, with increasing pairing interaction, from the fermion

pair breaking instability to the well-known dynamical instability of lattice

bosons. Our most interesting finding is the existence of a transition, over a

range of fillings close to one fermion per site, from the fermion depairing

instability to the density wave instability as the strength of the pairing

interaction is increased. By sharp contrast, the ground state in this regime

evolves smoothly with increasing interaction analogous to the BCS-BEC

crossover.

\\ ( http://arxiv.org/abs/0802.2101 , 150kb)

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arXiv:0802.2222

Date: Fri, 15 Feb 2008 15:15:30 GMT (33kb)

Title: Nonlinear Schr\"odinger equation for a superfluid Fermi gas from BCS to

Bose crossover

Authors: S. K. Adhikari

Categories: cond-mat.other

Comments: 4 pages, 5 figures

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

We introduce a quasi-analytic nonlinear Schr\"odinger equation with beyond

mean-field corrections to describe the dynamics of a zero-temperature dilute

superfluid Fermi gas in the crossover from the weak-coupling

Bardeen-Cooper-Schrieffer (BCS) regime, where $k_F|a| \ll 1$ with $a$ the

s-wave scattering length and $k_F$ the Fermi momentum, through the unitarity

limit, $k_Fa \to \pm \infty$, to the Bose regime where $k_Fa >0$. The energy of

our model is parametrized using the known asymptotic behavior in the BCS, Bose,

and the unitarity limits and is in excellent agreement with accurate Green

function Monte Carlo calculations. The model generates good results for

frequencies of collective breathing oscillation of a trapped Fermi superfluid.

\\ ( http://arxiv.org/abs/0802.2222 , 33kb)

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arXiv:0802.2231

Date: Fri, 15 Feb 2008 15:50:10 GMT (476kb)

Title: Josephson oscillation of a superfluid Fermi gas

Authors: S. K. Adhikari

Categories: cond-mat.other

Comments: 7 pages, 10 figures

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

Using the complete numerical solution of a time-dependent three-dimensional

mean-field model we study the Josephson oscillation of a superfluid Fermi gas

(SFG) at zero temperature formed in a combined axially-symmetric harmonic plus

one-dimensional periodic optical-lattice (OL) potentials after displacing the

harmonic trap along the axial OL axis. We study the dependence of Josephson

frequency on the strength of the OL potential. The Josephson frequency

decreases with increasing strength as found in the experiment of Cataliotti et

al. [Science 293 (2001) 843] for a Bose-Einstein condensate and of the

experiment of Pezze et al. [Phys. Rev. Lett. 93 (2004) 120401] for an ideal

Fermi gas. We demonstrate a breakdown of Josephson oscillation in the SFG for a

large displacement of the harmonic trap. These features of Josephson

oscillation of a SFG can be tested experimentally.

\\ ( http://arxiv.org/abs/0802.2231 , 476kb)

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arXiv:0802.2136

Date: Fri, 15 Feb 2008 03:39:43 GMT (298kb)

Title: Large Cross-phase Modulation Based on Double EIT in a Four-level Tripod

Atomic System

Authors: Shujing Li, Xudong Yang, Xuemin Cao, Chunhong Zhang, Changde Xie, Hai

Wang

Categories: quant-ph

Comments: 13 pages, 4 figures

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

We report the experimental observations on the simultaneous EIT effects for

probe and trigger fields (double EIT) as well as the large cross-phase

modulation (XPM) between the two fields in a four-level tripod EIT system of

the D1 line of 87Rb atoms. The XPM coefficients (larger than 2*10-5cm2/W) and

the accompanying transmissions (higher than 60%) are measured at slightly

detuning of the probe field from the exact EIT resonance condition. The

presented system can be applied in the recently proposed quantum information

processing with weak cross-Kerr nonlinearities.

\\ ( http://arxiv.org/abs/0802.2136 , 298kb)

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arXiv:0802.2149

Date: Fri, 15 Feb 2008 08:34:51 GMT (66kb)

Title: Goos-H\"{a}nchen-Like Shifts in Atom Optics

Authors: Jianhua Huang, Zhenglu Duan, Hongyuan Ling, and Weiping Zhang

Categories: quant-ph

Comments: 7 pages, 4 figures

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

We consider the propagation of a matter wavepacket of two-level atoms through

a square potential created by a super-Gaussian laser beam. We explore the

matter wave analog of Goos-H\"{a}nchen shift within the framework of atom

optics where the roles of atom and light is exchanged with respect to

conventional optics. Using a vector theory, where atoms are treated as

particles possessing two internal spin components, we show that not only large

negative but also large positive Goos-H\"{a}nchen shifts can occur in the

reflected atomic beam.

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

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arXiv:0802.2444

Date: Mon, 18 Feb 2008 12:57:34 GMT (141kb)

Title: Quantum and quasi-classical types of superfluid turbulence

Authors: P. M. Walmsley and A. I. Golov

Categories: cond-mat.other

Comments: 4 pages, 5 figures

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

By colliding charged quantized vortex rings of radius R=0.6 microns in

superfluid 4He in the zero-temperature limit (T<0.5 K), we have succeeded in

generating tangles of quantized vortex line with negligible large-scale flow.

After such a tangle is created near one side of a cubic cell of side 4.5 cm, it

takes about 10 s for the turbulence to spread into all the volume and become

homogeneous. For this quantum regime of superfluid turbulence, the vortex line

length L was found to decay at late time t as L proportional to 1/t within at

least two orders of magnitude; the prefactor being independent of the initial

value of L. The corresponding effective kinematic viscosity is 0.1 circulation

quanta which is 30 times greater than that for quasi-classical turbulence

generated by large-scale flow at T=0. At T>0.7 K, when the density of thermal

excitations becomes substantial, a jet of ions generates quasi-classical

tangles identical to those produced by mechanical means.

\\ ( http://arxiv.org/abs/0802.2444 , 141kb)

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arXiv:0802.2455

Date: Mon, 18 Feb 2008 11:09:46 GMT (621kb)

Title: Pacifying the Fermi-liquid: battling the devious fermion signs

Authors: J. Zaanen, F. Kr\"uger, J.-H. She, D. Sadri, S. I. Mukhin

Categories: cond-mat.other

Comments: 28 pages, 5 figures

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

The fermion sign problem is studied in the path integral formalism. The

standard picture of Fermi liquids is first critically analyzed, pointing out

some of its rather peculiar properties. The insightful work of Ceperley in

constructing fermionic path integrals in terms of constrained world-lines is

then reviewed. In this representation, the minus signs associated with

Fermi-Dirac statistics are self consistently translated into a geometrical

constraint structure (the {\em nodal hypersurface}) acting on an effective

bosonic dynamics. As an illustrative example we use this formalism to study

1+1-dimensional systems, where statistics are irrelevant, and hence the sign

problem can be circumvented. In this low-dimensional example, the structure of

the nodal constraints leads to a lucid picture of the entropic interaction

essential to one-dimensional physics. Working with the path integral in

momentum space, we then show that the Fermi gas can be understood by analogy to

a Mott insulator in a harmonic trap. Going back to real space, we discuss the

topological properties of the nodal cells, and suggest a new holographic

conjecture relating Fermi liquids in higher dimensions to soft-core bosons in

one dimension. We also discuss some possible connections between mixed

Bose/Fermi systems and supersymmetry.

\\ ( http://arxiv.org/abs/0802.2455 , 621kb)

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arXiv:0802.2498

Date: Mon, 18 Feb 2008 15:34:29 GMT (36kb)

Title: Ultracold bosons in disordered superlattices: Mott-insulators induced by

tunneling

Authors: D. Muth, A. Mering and M. Fleischhauer

Categories: cond-mat.other cond-mat.dis-nn

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

We analyse the phase diagram of ultra-cold bosons in a one-dimensional

superlattice potential with disorder using the time evolving block decimation

algorithm for infinite sized systems (iTEBD). For degenerate potential energies

within the unit cell of the superlattice loophole-shaped insulating phases with

non-integer filling emerge with a particle-hole gap proportional to the boson

hopping. Adding a small amount of disorder destroys this gap. For not too large

disorder the loophole Mott regions detach from the axis of vanishing hopping

giving rise to insulating islands. Thus the system shows a transition from a

compressible Bose-glass to a Mott-insulating phase with increasing hopping

amplitude. We present a straight forward effective model for the dynamics

within a unit cell which provides a simple explanation for the emergence of

Mott-insulating islands. In particular it gives rather accurate predictions for

the inner critical point of the Bose-glass to Mott-insulator transition.

\\ ( http://arxiv.org/abs/0802.2498 , 36kb)

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arXiv:0802.2548

Date: Mon, 18 Feb 2008 21:01:50 GMT (223kb)

Title: Preemptive vortex-loop proliferation in multicomponent interacting

Bose--Einstein condensates

Authors: E. K. Dahl, E. Babaev, S. Kragset, and A. Sudbo

Categories: cond-mat.stat-mech

Comments: 12 pages, 10 figures. Submitted to Physical Review B

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

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We use analytical arguments and large-scale Monte Carlo calculations to

investigate the nature of the phase transitions between distinct complex

superfluid phases in a two-component Bose--Einstein condensate when a

non-dissipative drag between the two components is being varied. We focus on

understanding the role of topological defects in various phase transitions and

develop vortex-matter arguments allowing an analytical description of the phase

diagram. We find the behavior of fluctuation induced vortex matter to be much

more complex and substantially different from that of single-component

superfluids. We propose and investigate numerically a novel drag-induced

``preemptive vortex loop proliferation'' transition. Such a transition may be a

quite generic feature in many multicomponent systems where symmetry is restored

by a gas of several kinds of competing vortex loops.

\\ ( http://arxiv.org/abs/0802.2548 , 223kb)

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arXiv:0802.2591

Date: Tue, 19 Feb 2008 07:38:49 GMT (382kb)

Title: Studying a dual-species BEC with tunable interactions

Authors: S. B. Papp, J. M. Pino, and C. E. Wieman

Categories: cond-mat.other

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

We report on the observation of controllable spatial separation in a

dual-species Bose-Einstein condensate (BEC) with $^{85}$Rb and $^{87}$Rb.

Interparticle interactions between the different components can change the

miscibility of the two quantum fluids. In our experiments, we clearly observe

the immiscible nature of the two simultaneously Bose-condensed species via

their spatial separation. Furthermore the $^{85}$Rb Feshbach resonance near 155

G is used to change them between miscible and immiscible by tuning the

$^{85}$Rb scattering length. Our apparatus is also able to create $^{85}$Rb

condensates with up to $8\times104$ atoms which represents a significant

improvement over previous work.

\\ ( http://arxiv.org/abs/0802.2591 , 382kb)

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arXiv:0802.2600

Date: Tue, 19 Feb 2008 07:20:05 GMT (96kb)

Title: Anomalous Monopole In an Interacting Boson System

Authors: Biao Wu, Qi Zhang and Jie Liu

Categories: cond-mat.other

Comments: 4 pages, 3 figures

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

Anomalous monopole of disk shape is found to exist in the semiclassical

theory of a two-mode interacting boson system. The quantum origin of this

anomaly is the collapsing or bundling of field lines of Berry curvature caused

by the interaction between bosons in the semiclassical limit. The significance

of this anomalous monopole is twofold: (1) it signals the failure of the von

Neumann-Wigner theorem in the semiclassical limit; (2) it indicates a breakdown

of the correspondence principle between quantum and classical dynamics.

\\ ( http://arxiv.org/abs/0802.2600 , 96kb)

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arXiv:0802.2601

Date: Tue, 19 Feb 2008 07:31:16 GMT (832kb)

Title: A quasi-monomode guided atom-laser from an all-optical Bose-Einstein

condensate

Authors: A. Couvert (LKB - Lhomond), M. Jeppesen (LKB - Lhomond), T. Kawalec

(LKB - Lhomond), G. Reinaudi (LKB - Lhomond), R. Mathevet (LCAR), David

Guery-Odelin (LKB - Lhomond, LCAR)

Categories: cond-mat.other

Comments: 4 pages, 4 figures

Proxy: ccsd hal-00257245

\\

We report the achievement of an optically guided and quasi-monomode atom

laser, in all spin projection states ($m_F =$ $-1$, $0$ and $+1$) of $F=1$ in

Rubidium 87. The atom laser source is a Bose-Einstein condensate (BEC) in a

crossed dipole trap, purified to any one spin projection state by a

spin-distillation process applied during the evaporation to BEC. The atom laser

is outcoupled by an inhomogenous magnetic field, applied along the waveguide

axis. The mean excitation number in the transverse modes is $\langle n \rangle

= 0.65 \pm 0.05$ for $m_F = 0 $ and $ \langle n \rangle = 0.8 \pm 0.3$ for the

low field seeker $m_F = -1$.

\\ ( http://arxiv.org/abs/0802.2601 , 832kb)

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arXiv:0802.2573

Date: Tue, 19 Feb 2008 01:40:00 GMT (373kb)

Title: Mean-field dynamics of a Bose Josephson junction in an optical cavity

Authors: J. M. Zhang, W. M. Liu, and D. L. Zhou

Categories: quant-ph

Comments: 10 pages, 2 figures

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

We study the mean-field dynamics of a Bose Josephson junction which is

dispersively coupled to a single mode of a high-finesse optical cavity. An

effective classical Hamiltonian for the Bose Josephson junction is derived and

its dynamics is studied in the perspective of phase portrait. It is shown that

the strong condensate-field coupling does alter the dynamics of the Bose

Josephson junction drastically. The possibility of coherent manipulating and

\textsl{in situ} observation of the dynamics of the Bose Josephson junction is

discussed.

\\ ( http://arxiv.org/abs/0802.2573 , 373kb)

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arXiv:0802.2553

Date: Mon, 18 Feb 2008 21:27:03 GMT (999kb)

Title: Ultracold atom-molecule collisions with fermionic atoms

Authors: J. P. D'Incao, B. D. Esry, and Chris H. Greene

Categories: physics.atom-ph

Comments: 6 pages, 2 figures

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

Elastic and inelastic properties of weakly bound s- and p-wave molecules of

fermionic atoms that collide with a third atom are investigated. Analysis of

calculated collisional properties of s-wave dimers of fermions in different

spin states permit us to compare and highlight the physical mechanisms that

determine the stability of s-wave and p-wave molecules. In contrast to s-wave

molecules, the collisional properties of p-wave molecules are found to be

largely insensitive to variations of the p-wave scattering length and that

these collisions will usually result in short molecular lifetimes. We also

discuss the importance of this result for both theories and experiments

involving degenerate Fermi gases.

\\ ( http://arxiv.org/abs/0802.2553 , 999kb)

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arXiv:0802.2811

Date: Wed, 20 Feb 2008 12:51:25 GMT (171kb)

Title: Effective-interaction approach to the many-boson problem

Authors: J. Christensson, C. Forss\'en, S. {\AA}berg and S.M. Reimann

Categories: cond-mat.other nucl-th physics.comp-ph

Comments: 4 pages, 4 figures

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

We show that the convergence behavior of the many-body numerical

diagonalization scheme for strongly interacting bosons in a trap can be

significantly improved by the Lee-Suzuki method adapted from nuclear physics:

One can construct an effective interaction that acts in a space much smaller

than the original Hilbert space. In particular for short-ranged forces and

strong correlations, the method offers a good estimate of the energy and the

excitation spectrum, at a computational cost several orders of magnitude

smaller than that required by the standard method.

\\ ( http://arxiv.org/abs/0802.2811 , 171kb)

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arXiv:0802.2923

Date: Wed, 20 Feb 2008 19:31:43 GMT (364kb)

Title: Diagrammatic Monte Carlo

Authors: Kris Van Houcke, Evgeny Kozik, Nikolay Prokof'ev, Boris Svistunov

Categories: cond-mat.stat-mech cond-mat.str-el

Comments: 15 pages, 7 figures. To appear in: Computer Simulation Studies in

Condensed Matter Physics XXI, Eds. D.P. Landau, S.P. Lewis, and H.B.

Schuttler (Springer Verlag, Heidelberg, Berlin 2008)

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

Diagrammatic Monte Carlo (DiagMC) is a numeric technique that allows one to

calculate quantities specified in terms of diagrammatic expansions, the latter

being a standard tool of many-body quantum statistics. The sign problem that is

typically fatal to Monte Carlo approaches, appears to be manageable with

DiagMC. Starting with a general introduction to the principles of DiagMC, we

present a detailed description of the DiagMC scheme for interacting fermions

(Hubbard model), as well as the first illustrative results for the equations of

state.

\\ ( http://arxiv.org/abs/0802.2923 , 364kb)

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arXiv:0802.2902 (*cross-listing*)

Date: Wed, 20 Feb 2008 17:53:42 GMT (897kb)

Title: Reflection of OH molecules from magnetic mirrors

Authors: Markus Metsala, Joop J. Gilijamse, Steven Hoekstra, Sebastiaan Y. T.

van de Meerakker, and Gerard Meijer

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

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

We have reflected a Stark-decelerated beam of OH molecules under normal

incidence from mirrors consisting of permanent magnets. Two different types of

magnetic mirrors have been demonstrated. A long-range flat mirror made from a

large disc magnet has been used to spatially focus the reflected beam in the

longitudinal direction ("bunching"). A short-range curved mirror composed of an

array of small cube magnets has been used for transverse focusing of the

reflected beam.

\\ ( http://arxiv.org/abs/0802.2902 , 897kb)

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arXiv:0802.3019

Date: Thu, 21 Feb 2008 11:23:49 GMT (516kb)

Title: Faraday instability in a two-component Bose Einstein condensate

Authors: Aranya B. Bhattacherjee

Categories: cond-mat.other

Comments: 6 pages, 4 figures

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

Motivated by recent experiments on Faraday waves in Bose Einstein condensates

(BEC) we investigate the dynamics of two component cigar shaped BEC subject to

periodic modulation of the strength of the transverse confinement. It is shown

that two coupled Mathieu equations govern the dynamics of the system. We found

that the two component BEC in a phase mixed state is relatively more unstable

towards pattern formation than the phase segregated state.

\\ ( http://arxiv.org/abs/0802.3019 , 516kb)

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arXiv:0802.3158

Date: Thu, 21 Feb 2008 16:32:43 GMT (28kb)

Title: Probing ultra-cold Fermi atoms with a single ion

Authors: Y. Sherkunov, B. Muzykantskii, N. d'Ambrumenil, B. Simons

Categories: cond-mat.str-el

Comments: 4 pages, 2 figures

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

We study an ion embedded in an atomic Fermi gas and compute the two-photon

Raman photo-association rate of the ion and an atom. We show, that, as a

function of the detunings between the frequencies of the two incident lasers

and transition energies in the ion-atom system, the photo-association rate

directly measures the energy distribution in the Fermi gas around the ion. We

describe an experiment to measure the photo-association time using an ion trap.

The position of the ion can be scanned through the Fermi gas. This experiment

would provide a non-destructive probe of the local energy and spin-state

distribution of the Fermi gas with resolution on the nanometer scale.

\\ ( http://arxiv.org/abs/0802.3158 , 28kb)

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arXiv:0802.3202

Date: Thu, 21 Feb 2008 20:30:46 GMT (262kb,D)

Title: Interaction Quench in the Hubbard model

Authors: M. Moeckel and S. Kehrein

Categories: cond-mat.str-el

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

Motivated by recent experiments in ultracold atomic gases that explore the

nonequilibrium dynamics of interacting quantum many-body systems, we

investigate the opposite limit of Landau's Fermi liquid paradigm: We study a

Hubbard model with a sudden interaction quench, that is the interaction is

switched on at time t=0. Using the flow equation method, we are able to study

the real time dynamics for weak interaction U in a systematic expansion and

find three clearly separated time regimes: i) An initial buildup of

correlations where the quasiparticles are formed. ii) An intermediate

quasi-steady regime resembling a zero temperature Fermi liquid with a

nonequilibrium quasiparticle distribution function. iii) The long time limit

described by a quantum Boltzmann equation leading to thermalization with a

temperature T proportional to U.

\\ ( http://arxiv.org/abs/0802.3202 , 262kb)

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arXiv:0802.3005

Date: Thu, 21 Feb 2008 09:43:01 GMT (39kb)

Title: Strong interaction between light and a single trapped atom without a

cavity

Authors: Meng Khoon Tey, Zilong Chen, Syed Abdullah Aljunid, Brenda Chng,

Florian Huber, Gleb Maslennikov, Christian Kurtsiefer

Categories: quant-ph

Comments: 11 pages, 4 figures

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

Coupling of light to an atom at single quanta level with high probability is

a building block for many quantum information processing protocols. It is

commonly believed that efficient coupling is only achievable with the

assistance of a cavity. Here, we report on an observation of substantial

coupling between a light beam and a single $^{87}$Rb atom in a direct

extinction measurement by focusing light to a small spot with a single lens.

Our result opens a new perspective on processing quantum information carried by

light using atoms, and is important to many ongoing experiments that require

strong coupling of single photons to an atom in free space.

\\ ( http://arxiv.org/abs/0802.3005 , 39kb)

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arXiv:0802.3163

Date: Thu, 21 Feb 2008 16:48:11 GMT (657kb,D)

Title: Creation, manipulation, and detection of anyons in optical lattices

Authors: M. Aguado, G. K. Brennen, F. Verstraete, J. I. Cirac

Categories: quant-ph

Comments: 8 pages, 4 pdf figures

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

Anyons are particle-like excitations of strongly correlated phases of matter

with very exotic physical properties. Unlike bosons and fermions, they have

so-called fractional statistics, which are characterized by non-trivial changes

in the quantum wavefunction when two of them interchange their positions. Those

changes can, in turn, be used to perform quantum computations [A. Yu. Kitaev,

Annals Phys. 303, 2 (2003), arXiv:quant-ph/9707021v1], something which has

renewed the interest in the investigation of physical systems where anyons may

be present, manipulated and detected. In this work we show how this can be

accomplished in the context of optical lattices. Our proposal just requires one

(or several) ancilla particle(s) which can: (i) undergo single particle gates;

(ii) be moved close to each constituents of the lattice and undergo a simple

quantum gate; (iii) be detected. Recent experimental progress with atoms in

optical lattices makes our proposal feasible with present technology.

\\ ( http://arxiv.org/abs/0802.3163 , 657kb)

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arXiv:0802.3194

Date: Thu, 21 Feb 2008 19:47:46 GMT (233kb)

Title: A Deeper Look at Student Learning of Quantum Mechanics: the Case of

Tunneling

Authors: S. B. McKagan, K. K. Perkins, and C. E. Wieman

Categories: physics.ed-ph

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

We report on a qualitative study of student learning of quantum tunneling in

traditional and reformed modern physics courses. In the reformed courses, which

were designed to address student difficulties found in previous research,

students still struggle with many of the same issues found in other courses,

but the reasons for these difficulties are more subtle, and many new issues are

brought to the surface. By explicitly discussing how to build models of

potential energy and relate these models to real physical systems, we have

opened up a floodgate of deep and difficult questions as students struggle to

make sense of these models. We conclude that the difficulties found in previous

research are the tip of the iceberg, and the real issue at the heart of student

difficulties in learning quantum tunneling is the struggle to build the complex

models that are implicit in experts' understanding but often not discussed

explicitly with students.

\\ ( http://arxiv.org/abs/0802.3194 , 233kb)

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arXiv:0709.2757

replaced with revised version Fri, 15 Feb 2008 13:05:03 GMT (15kb)

Title: Tkachenko modes in a superfluid Fermi gas at unitarity

Authors: Gentaro Watanabe, Marco Cozzini, and Sandro Stringari

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

Comments: 5 pages, 1 figure; minor changes, now published as Phys. Rev. A 77,

021602(R) (2008)

\\ ( http://arxiv.org/abs/0709.2757 , 15kb)

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arXiv:0710.4220

replaced with revised version Thu, 14 Feb 2008 23:31:29 GMT (646kb)

Title: Ultracold atoms in optical lattices generated by quantized light fields

Authors: Christoph Maschler, Igor B. Mekhov, Helmut Ritsch

Categories: quant-ph

Comments: 17 pages, 10 figures, Published version

Journal-ref: Eur. Phys. J. D,46, 545-560 (2008)

DOI: 10.1140/epjd/e2008-00016-4

\\ ( http://arxiv.org/abs/0710.4220 , 646kb)

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arXiv:quant-ph/0702109

replaced with revised version Mon, 18 Feb 2008 11:14:03 GMT (62kb)

Title: Vector Cooper Pairs and Coherent-Population-Trapping-like States in

Ensemble of Interacting Fermions

Authors: A.V. Taichenachev and V.I. Yudin

Categories: quant-ph cond-mat.str-el cond-mat.supr-con physics.atom-ph

Comments: revtex, 12 pages, 2 figures

\\ ( http://arxiv.org/abs/quant-ph/0702109 , 62kb)

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arXiv:0711.3562

replaced with revised version Mon, 18 Feb 2008 07:29:18 GMT (106kb)

Title: EPR argument and Bell inequalities for Bose-Einstein spin condensates

Authors: Franck Lalo\"e (LKB - Lhomond), William J. Mullin (UMASS)

Categories: quant-ph cond-mat.other

Comments: a few misprints corrected, a reference added. This is the published

version

Proxy: ccsd hal-00189827

Journal-ref: Physical Review A: Atomic, Molecular and Optical Physics 77 (2008)

022108

DOI: 10.1103/PhysRevA.77.022108

\\ ( http://arxiv.org/abs/0711.3562 , 106kb)

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arXiv:0706.3686

replaced with revised version Tue, 19 Feb 2008 09:58:02 GMT (377kb)

Title: Non-equilibrium solid state quantum condensates: the effect of particle

flux on density profiles

Authors: Jonathan Keeling, Natalia G. Berloff

Categories: cond-mat.other

Comments: New content on stability of symmetryic solutions and possibility of

spontaneous vortex lattice. 4 pages, 3 figures

\\ ( http://arxiv.org/abs/0706.3686 , 377kb)

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arXiv:0707.4189

replaced with revised version Wed, 20 Feb 2008 02:19:01 GMT (179kb)

Title: Superfluid-Insulator Transition and Fermion Pairing in Bose-Fermi

Mixtures

Authors: Kun Yang

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

Comments: Expanded version as appeared in print

Journal-ref: Phys. Rev. B 77, 085115 (2008)

DOI: 10.1103/PhysRevB.77.085115

\\ ( http://arxiv.org/abs/0707.4189 , 179kb)

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arXiv:0801.4466

replaced with revised version Wed, 20 Feb 2008 10:58:03 GMT (301kb)

Title: 2PI nonequilibrium versus transport equations for an ultracold Bose gas

Authors: Alexander Bransch\"adel and Thomas Gasenzer

Categories: cond-mat.other hep-ph

Comments: 24 pages, 7 figures. References added

Report-no: Heidelberg preprint HD-THEP-08-02

\\ ( http://arxiv.org/abs/0801.4466 , 301kb)

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arXiv:0707.0675

replaced with revised version Thu, 21 Feb 2008 17:59:20 GMT (265kb)

Title: Disorder-Induced Order in Two-Component Bose-Einstein Condensates

Authors: Armand Niederberger, Thomas Schulte, Jan Wehr, Maciej Lewenstein,

Laurent Sanchez-Palencia, Krzysztof Sacha

Categories: cond-mat.other cond-mat.dis-nn

Comments: 4 pages, 3 figures

Journal-ref: Phys. Rev. Lett. 100, 030403 (2008)

\\ ( http://arxiv.org/abs/0707.0675 , 265kb)

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arXiv:0801.3465

replaced with revised version Thu, 21 Feb 2008 19:20:50 GMT (51kb)

Title: Mixtures of strongly interacting bosons in optical lattices

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

Categories: cond-mat.other quant-ph

Comments: 9 pages, 3 figures; some changes in the text have been introduced;

the title has been slightly changed

\\ ( http://arxiv.org/abs/0801.3465 , 51kb)

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arXiv:0802.2101

replaced with revised version Wed, 20 Feb 2008 23:14:54 GMT (100kb)

Title: Stability of Superflow for Ultracold Fermions in Optical Lattices

Authors: A.A. Burkov, Arun Paramekanti

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

Comments: 4+ pages, 2 figures, typos corrected, references added

\\ ( http://arxiv.org/abs/0802.2101 , 100kb)

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arXiv:0711.3831 (*cross-listing*)

replaced with revised version Thu, 21 Feb 2008 16:48:06 GMT (546kb,D)

Title: Generation of macroscopic superposition states in ring superlattices

Authors: Andreas Nunnenkamp, Ana Maria Rey, Keith Burnett

Categories: cond-mat.other quant-ph

Comments: 9 pages, 10 figures; minor corrections

\\ ( http://arxiv.org/abs/0711.3831 , 546kb)

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arXiv:0708.2638

replaced with revised version Thu, 21 Feb 2008 01:14:59 GMT (82kb)

Title: Three-State Feshbach Resonances Mediated By Second-Order Couplings

Authors: Christopher J. Hemming, Roman V. Krems

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

Comments: 27 pages, 4 figures; added a reference; journal reference/DOI refer

to final published version, which is a shortened and modified version of this

preprint

Journal-ref: Phys. Rev. A 77, 022705 (2008)

DOI: 10.1103/PhysRevA.77.022705

\\ ( http://arxiv.org/abs/0708.2638 , 82kb)

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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 Mon Mar 03 2008 - 09:49:03 EST

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