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

Date: Tue, 27 Jun 2006 15:09:29 +1000 (EST)

Date: Tue, 27 Jun 2006 15:09:29 +1000 (EST)

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

Another week, and another day late - sorry yet again. Today's message includes

the Tuesday arXiv mailing.

Interesting looking papers this week include two papers on imaging Mott

Insulator shells in a harmonic trap: one each from the groups of Bloch and

Ketterle. Also a paper introducing "Atomtronics" out of the group of Murray

Holland.

Home page: http://www.physics.uq.edu.au/people/mdavis/matts_arXiv/

The abstracts:

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Paper: cond-mat/0606470

Date: Sun, 18 Jun 2006 03:09:45 GMT (48kb)

Title: Superconductivity on the honeycomb lattice: Semimetal-to-superconductor

transition and BCS-BEC crossover

Authors: Erhai Zhao, Arun Paramekanti (University of Toronto)

Comments: 4+ pages, 3 figures (comments welcome)

Subj-class: Superconductivity; Strongly Correlated Electrons

\\

We study the attractive Hubbard model on the two-dimensional honeycomb

lattice, focusing on the semimetal-to-superconductor transition at half-filling

(at a critical $U_c$) and the BCS-to-BEC crossover for small deviations from

half-filling. At a small density deviation $\delta n$ from half-filling, we

show that although the underlying metallic state has a small Fermi surface and

a small effective Fermi energy $\sim v_F \sqrt{\delta n}$, the BCS-to-BEC

crossover is very different from a dilute gas of fermions in that it occurs at

an interaction strength $U \gg v_F \sqrt{\delta n}$. Rather, the crossover and

the maximum SC transition occur at $U \sim U_c$, and thus lie close to the

quantum critical point at half-filling. We compute the SC collective modes

spectra in the crossover regime and show that an undamped Leggett mode emerges

deep in the BEC regime in addition to the Goldstone sound mode. In the

semimetal phase, the long wavelength SC fluctuations are critically damped by

the gapless Dirac fermions while short wavelength fluctuations can propagate as

weakly damped excitations.

\\ ( http://arXiv.org/abs/cond-mat/0606470 , 48kb)

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Paper: cond-mat/0606471

Date: Sun, 18 Jun 2006 06:45:43 GMT (42kb)

Title: Studies of bosons in optical lattices in a harmonic potential

Authors: R. Ramakumar, A. N. Das, and S. Sil

Comments: 9 pages, 16 figures

Subj-class: Statistical Mechanics; Other

\\

We present a theoretical study of bose condensation and specific heat of

non-interacting bosons in finite lattices in harmonic potentials in one, two,

and three dimensions. We numerically diagonalize the Hamiltonian to obtain the

energy levels of the systems. Using the energy levels thus obtained, we

investigate the temperature dependence, dimensionality effects, lattice size

dependence, and evolution to the bulk limit of the condensate fraction and the

specific heat. The results obtained are contextualized within the current

experimental and theoretical scenario.

\\ ( http://arXiv.org/abs/cond-mat/0606471 , 42kb)

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Paper: cond-mat/0606484

Date: Mon, 19 Jun 2006 10:10:06 GMT (45kb)

Title: Gapless Hartree-Fock-Bogoliubov Approximation for Bose Gases

Authors: V.I. Yukalov and H. Kleinert

Comments: Latex file, 22 pages, 2 figures

Subj-class: Statistical Mechanics

Journal-ref: Phys. Rev. A 73 (2006) 063612-9

\\

A dilute Bose system with Bose-Einstein condensate is considered. It is shown

that the Hartree-Fock-Bogolubov approximation can be made both conserving as

well as gapless. This is achieved by taking into account all physical

normalization conditions, that is, the normalization condition for the

condensed particles and that for the total number of particles. Two Lagrange

multipliers, introduced for preserving these normalization conditions, make the

consideration completely self-consistent.

\\ ( http://arXiv.org/abs/cond-mat/0606484 , 45kb)

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Paper: cond-mat/0606490

Date: Mon, 19 Jun 2006 15:27:24 GMT (205kb)

Title: Spin Diffusion in Trapped Gases: Anisotropy in Dipole and Quadrupole

Modes

Authors: W. J. Mullin, R. J. Ragan

Comments: 18 pages, 9 figures

Subj-class: Other; Statistical Mechanics

\\

Recent experiments in a mixture of two hyperfine states of trapped Bose gases

show behavior analogous to a spin-1/2 system, including transverse spin waves

and other familiar Leggett-Rice-type effects. We have derived the kinetic

equations applicable to these systems, including the spin dependence of

interparticle interactions in the collision integral, and have solved for

spin-wave frequencies and longitudinal and transverse diffusion constants in

the Boltzmann limit. We find that, while the transverse and longitudinal

collision times for trapped Fermi gases are identical, the Bose gas shows

unusual diffusion anisotropy in both dipole and quadrupole modes. Moreover, the

lack of spin isotropy in the interactions leads to the non-conservation of

transverse spin, which in turn has novel effects on the hydrodynamic modes.

\\ ( http://arXiv.org/abs/cond-mat/0606490 , 205kb)

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Paper (*cross-listing*): nucl-th/0606019

Date: Tue, 13 Jun 2006 18:05:41 GMT (124kb)

Title: From Trapped Atoms to Liberated Quarks

Authors: Thomas Schaefer (North Carolina State University)

Comments: 13 pages, 5 figures; to appear in the proceedings of the

International Symposium on Heavy Ion Physics 2006, Frankfurt, Germany;

International Journal of Modern Physics E, in press

Subj-class: Nuclear Theory; Superconductivity

\\

We discuss some aspects of cold atomic gases in the unitarity limit that are

of interest in connection with the physics of dense hadronic matter. We

consider, in particular, the equation of state at zero temperature, the

magnitude of the pairing gap, and the phase diagram at non-zero polarization.

\\ ( http://arXiv.org/abs/nucl-th/0606019 , 124kb)

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Paper: cond-mat/0603404

replaced with revised version Sat, 17 Jun 2006 19:17:24 GMT (119kb)

Title: Dynamical vanishing of the order parameter in a fermionic condensate

Authors: Emil A. Yuzbashyan and Maxim Dzero

Comments: 4 pages, 3 figures, journal version

Subj-class: Superconductivity; Other

Journal-ref: Phys. Rev. Lett. 96, 230404 (2006)

\\ ( http://arXiv.org/abs/cond-mat/0603404 , 119kb)

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Paper: cond-mat/0602483

replaced with revised version Mon, 19 Jun 2006 00:39:38 GMT (85kb)

Title: Ground-state properties of one-dimensional ultracold Bose gases in a

hard-wall trap

Authors: Yajiang Hao, Yunbo Zhang, J.-Q. Liang and Shu Chen

Comments: 7 pages, 6 figures, version published in Phys. Rev. A

Subj-class: Strongly Correlated Electrons

Journal-ref: Phys. Rev. A 73, 063617 (2006)

\\ ( http://arXiv.org/abs/cond-mat/0602483 , 85kb)

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Paper: cond-mat/0604673

replaced with revised version Mon, 19 Jun 2006 16:02:46 GMT (127kb)

Title: Evolution from a Bose-Einstein Condensate to a Tonks-Girardeau Gas: An

Exact Diagonalization Study

Authors: Frank Deuretzbacher, Kai Bongs, Klaus Sengstock, Daniela Pfannkuche

Comments: 5 pages, 5 figures

Subj-class: Other

\\ ( http://arXiv.org/abs/cond-mat/0604673 , 127kb)

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Paper: quant-ph/0606145

Date: Sun, 18 Jun 2006 12:55:40 GMT (607kb)

Title: Atom Lithography with Near-Resonant Light Masks: Quantum Optimization

Analysis

Authors: R. Arun, Offir Cohen, and I.Sh. Averbukh

Comments: 10 pages including 11 figures in Revtex

\\

We study the optimal focusing of two-level atoms with a near resonant

standing wave light, using both classical and quantum treatments of the

problem. Operation of the focusing setup is considered as a nonlinear spatial

squeezing of atoms in the thin- and thick-lens regimes. It is found that the

near-resonant standing wave focuses the atoms with a reduced background in

comparison with far-detuned light fields. For some parameters, the quantum

atomic distribution shows even better localization than the classical one.

Spontaneous emission effects are included via the technique of quantum Monte

Carlo wave function simulations. We investigate the extent to which

non-adiabatic and spontaneous emission effects limit the achievable minimal

size of the deposited structures.

\\ ( http://arXiv.org/abs/quant-ph/0606145 , 607kb)

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Paper: quant-ph/0606147

Date: Mon, 19 Jun 2006 17:23:05 GMT (655kb)

Title: Theory for a Hanbury Brown Twiss experiment with a pulsed atomic beam

Authors: Jose Viana Gomes (LCFIO), Aur\'{e}lien Perrin (LCFIO), Martijn

Schellekens (LCFIO), Denis Boiron (LCFIO), Christoph I. Westbrook (LCFIO),

Michael Belsley

Proxy: ccsd ccsd-00080649

\\

We have studied one-body and two-body correlation functions in a

ballistically expanding, non-interacting atomic cloud in the presence of

gravity. We find that the correlation functions are equivalent to those at

thermal equilibrium in the trap with an appropriate rescaling of the

coordinates. We derive simple expressions for the correlation lengths and give

some physical interpretations. Finally a simple model to take into account

finite detector resolution is discussed.

\\ ( http://arXiv.org/abs/quant-ph/0606147 , 655kb)

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Paper: quant-ph/0606155

Date: Mon, 19 Jun 2006 15:25:49 GMT (100kb)

Title: Coherent control of collective spontaneous emission in an extended

atomic ensemble and quantum storage

Authors: Alexey Kalachev, Stefan Kroll

Comments: 11 pages, 4 figures, submitted to PRA

\\

Coherent control of collective spontaneous emission in an extended atomic

ensemble resonantly interacting with single-photon wave packets is analyzed. A

scheme for coherent manipulation of collective atomic states is developed such

that superradiant states of the atomic system can be converted into subradiant

ones and vice versa. Possible applications of such a scheme for optical quantum

state storage and single-photon wave packet shaping are discussed. It is shown

that also in the absence of inhomogeneous broadening of the resonant line,

single-photon wave packets with arbitrary pulse shape may be recorded as a

subradiant state and reconstructed even although the duration of the wave

packets is larger than the superradiant life-time. Specifically the

applicability for storing time-bin qubits, which are used in quantum

cryptography is analyzed.

\\ ( http://arXiv.org/abs/quant-ph/0606155 , 100kb)

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Paper: quant-ph/0603016

replaced with revised version Mon, 19 Jun 2006 13:15:31 GMT (249kb)

Title: Quantum correlations of two optical fields close to electromagnetically

induced transparency

Authors: Alice Sinatra (LKB - Lhomond)

Comments: 4 pages, 5 figures

Proxy: ccsd ccsd-00019947

\\ ( http://arXiv.org/abs/quant-ph/0603016 , 249kb)

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Paper: physics/0606165

Date: Mon, 19 Jun 2006 07:16:39 GMT (822kb)

Title: Manipulation of ultracold atoms in dressed adiabatic radio frequency

potentials

Authors: I. Lesanovsky, S.Hofferberth, J.Schmiedmayer, and P. Schmelcher

Subj-class: Atomic Physics

\\

We explore properties of atoms whose magnetic hyperfine sub-levels are

coupled by an external magnetic radio frequency (rf) field. We perform a

thorough theoretical analysis of this driven system and present a number of

systematic approximations which eventually give rise to dressed adiabatic radio

frequency potentials. The predictions of this analytical investigation are

compared to numerically exact results obtained by a wave packet propagation. We

outline the versatility and flexibility of this new class of potentials and

demonstrate their potential use to build atom optical elements such as

double-wells, interferometers and ringtraps. Moreover, we perform simulations

of interference experiments carried out in rf induced double-well potentials.

We discuss how the nature of the atom-field coupling mechanism gives rise to a

decrease of the interference contrast.

\\ ( http://arXiv.org/abs/physics/0606165 , 822kb)

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Paper: cond-mat/0603011

replaced with revised version Tue, 20 Jun 2006 01:59:40 GMT (96kb)

Title: BCS-BEC crossover in an asymmetric two-component Fermi gas

Authors: Xia-Ji Liu and Hui Hu

Comments: 7 pages + 3 figures; To appear in Europhysics Letters

Subj-class: Statistical Mechanics; Superconductivity

\\ ( http://arXiv.org/abs/cond-mat/0603011 , 96kb)

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Paper: quant-ph/0606162

Date: Tue, 20 Jun 2006 06:31:43 GMT (215kb)

Title: Quantum computing with magnetic atoms in optical lattices of reduced

periodicity

Authors: Boris Ravaine, Andrei Derevianko, P.R. Berman

\\

We investigate the feasibility of combining Raman optical lattices with a

quantum computing architecture based on lattice-confined magnetically

interacting neutral atoms. A particular advantage of the standing Raman field

lattices comes from reduced interatomic separations leading to increased

interatomic interactions and improved multi-qubit gate performance.

Specifically, we analyze a $J=3/2$ Zeeman system placed in $% \sigma

_{+}-\sigma_{-}$ Raman fields which exhibit $\lambda /4$ periodicity. We find

that the resulting CNOT gate operations times are in the order of millisecond.

We also investigate motional and magnetic-field induced decoherences specific

to the proposed architecture.

\\ ( http://arXiv.org/abs/quant-ph/0606162 , 215kb)

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Paper: quant-ph/0602025

replaced with revised version Tue, 20 Jun 2006 16:54:09 GMT (225kb)

Title: Macroscopic superpositions of superfluid flows

Authors: David W. Hallwood, Jacob Dunningham, Keith Burnett

Comments: 4 pages, 4 figures, submitted to New J. Phys. changed content focus

\\ ( http://arXiv.org/abs/quant-ph/0602025 , 225kb)

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Paper: cond-mat/0606540

Date: Wed, 21 Jun 2006 04:22:44 GMT (524kb)

Title: Axicon Lens for Coherent Matter Waves

Authors: S. R. Muniz, S. D. Jenkins, T. A. B. Kennedy, D. S. Naik, and C. Raman

Comments: 11 pages, 5 figures, Multimedia files (movies) available in our

website: http://www.physics.gatech.edu/chandra/index.htm

Subj-class: Other

\\

We have realized a conical matter wave lens. The repulsive potential of a

focused laser beam was used to launch a Bose-Einstein condensate into a

radially expanding wavepacket whose perfect ring shape was ensured by energy

conservation. In spite of significant interactions between atoms, the spatial

and velocity widths of the ring along its radial dimension remained extremely

narrow, as also confirmed by numerical simulations. Our results open the

possibility for cylindrical atom optics without the perturbing effect of

mean-field interactions.

\\ ( http://arXiv.org/abs/cond-mat/0606540 , 524kb)

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Paper: cond-mat/0606554

Date: Wed, 21 Jun 2006 14:13:32 GMT (168kb)

Title: Input-output theory of cavities in the ultra-strong coupling regime: the

case of a time-independent vacuum Rabi frequency

Authors: Cristiano Ciuti (LPA), Iacopo Carusotto (BEC-CNR-INFM)

Proxy: ccsd ccsd-00080977

Subj-class: Other

\\

We present a full quantum theory for the dissipative dynamics of an optical

cavity in the ultra-strong light-matter coupling regime, in which the vacuum

Rabi frequency is comparable to the electronic transition frequency and the

anti-resonant terms of the light-matter coupling play an important role. In

particular, our model can be applied to the case of intersubband transitions in

doped semiconductor quantum wells embedded in a microcavity. The coupling of

the intracavity photonic mode and of the electronic polarization to the

external, frequency-dependent, dissipation baths is taken into account by means

of quantum Langevin equations in the input-output formalism. Observable spectra

(reflection, absorption, transmission and electroluminescence) are calculated

analytically in the case of a time-independent vacuum Rabi frequency.

\\ ( http://arXiv.org/abs/cond-mat/0606554 , 168kb)

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Paper: cond-mat/0604137

replaced with revised version Wed, 21 Jun 2006 09:35:43 GMT (28kb)

Title: Fermion Cooper Pairing with Unequal Masses: Standard Field Theory

Approach

Authors: Lianyi He, Meng Jin and Pengfei Zhuang

Comments: 13 pages, 2 figures, title changed

Subj-class: Superconductivity

\\ ( http://arXiv.org/abs/cond-mat/0604137 , 28kb)

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Paper: cond-mat/0604183

replaced with revised version Wed, 21 Jun 2006 11:27:57 GMT (26kb)

Title: Collisional relaxation of Feshbach molecules and three-body

recombination in 87Rb Bose-Einstein condensates

Authors: G. Smirne, R. M. Godun, D. Cassettari, V. Boyer, C. J. Foot, T. Volz,

N. Syassen, S. D\"urr, G. Rempe, M. D. Lee, K. Goral, T. Koehler

Comments: 4 pages, 3 eps figures

Subj-class: Other

\\ ( http://arXiv.org/abs/cond-mat/0604183 , 26kb)

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Paper: cond-mat/0605736

replaced with revised version Tue, 20 Jun 2006 22:51:11 GMT (154kb)

Title: Long Distance Transport of Ultracold Atoms using a 1D optical lattice

Authors: Stefan Schmid, Gregor Thalhammer, Klaus Winkler, Florian Lang, and

Johannes Hecker Denschlag

Comments: 15 pages, 8 figures

Subj-class: Other

\\ ( http://arXiv.org/abs/cond-mat/0605736 , 154kb)

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Paper: cond-mat/0606569

Date: Thu, 22 Jun 2006 08:40:38 GMT (236kb)

Title: Critical Temperature of a Chromium Condensate

Authors: Konstantin Glaum, Axel Pelster, Hagen Kleinert, and Tilman Pfau

Subj-class: Statistical Mechanics

\\

We calculate the effect of the magnetic dipole-dipole interaction upon the

Bose-Einstein condensation temperature of chromium in the ongoing Stuttgart

experiment. The dipolar shift of the critical temperature depends on the angle

between the symmetry axes of the trap and the aligned atomic magnetic moments,

and is extremal for parallel or orthogonal orientations, respectively. The

difference of both critical temperatures exhibits most clearly the magnetic

dipole-dipole interaction and can be enhanced by increasing both the number of

chromium atoms and the anisotropy of the trap.

\\ ( http://arXiv.org/abs/cond-mat/0606569 , 236kb)

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Paper: cond-mat/0606571

Date: Thu, 22 Jun 2006 11:05:56 GMT (37kb)

Title: Macro-orbitals and microscopic theory of a system of interacting bosons

Authors: Yatendra S. Jain

Comments: 36 pages with 1 figure, related to superfluidity, BEC states, etc

Subj-class: Soft Condensed Matter

\\

Macro-orbital representation of a particle (detailed account given in

cond-mat/0603784) has been used to develop the microscopic theory of a system

of interacting bosons. It concludes that: (i) below certain temperature (say,

$T_{\lambda}$), particles assume a state of (q, -q) bound pairs, (ii) the

$\lambda-$transition is a consequence of inter-particle quantum correlations

clubbed with zero-point repulsion and inter-particle attraction and represents

an onset of the order-disorder of particles in their $\phi-$space followed

simultaneously by their BEC as (q, -q) bound pairs in a state of q = $q_o =

\pi/d$ and K = 0, (iii) particles at $T \le T_{\lambda}$ acquire collective

binding which locks them at <k> = 0, <r> = $\lambda/2$ and $\Delta\phi = 2n\pi$

(with n = 1, 2, 3, ...), (iv) the entire system assumes mechanical strain in

inter-particle bonds and behaves like a single macroscopic molecule, (v) there

exists an energy gap between the superfluid and normal fluid phases of the

system, (vi) the $\lambda-$transition represents the twin phenomena of broken

gauge symmetry and phase coherence, (vii) the system does not have p = 0

condensate, (viii) a new kind of quantum quasi-particle "omon" (a phononlike

wave of the oscillations of the momentum coordinates of particles) exists in

superfluid phase, etc. It explains the properties of He-II, including the

origin of quantized vortices, critical velocities, logarithmic singularity of

specific heat, etc. at quantitative level and provides microscopic foundation

to two fluid theory, $\Psi-$theory, idea of macroscopic wave function, etc. The

framework of the theory can unify the physics of interacting bosons and

fermions.

\\ ( http://arXiv.org/abs/cond-mat/0606571 , 37kb)

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Paper: quant-ph/0606180

Date: Wed, 21 Jun 2006 20:53:14 GMT (19kb)

Title: Cantilever cooling with radio frequency circuits

Authors: D. J. Wineland, J. Britton, R. J. Epstein, D. Leibfried, R. B.

Blakestad, K. Brown, J. D. Jost, C. Langer, R. Ozeri, S. Seidelin, and J.

Wesenberg

Comments: 4 pages, 1 figure

\\

We consider a method to reduce the kinetic energy in a low-order mode of a

miniature cantilever. If the cantilever contributes to the capacitance of a

driven RF circuit, a force on the cantilever exists due to the electric field

energy stored in the capacitance. If this force acts with an appropriate phase

shift relative to the motion of the cantilever, it can oppose the velocity of

the cantilever, leading to cooling. Such cooling may enable reaching the

quantum regime of cantilever motion.

\\ ( http://arXiv.org/abs/quant-ph/0606180 , 19kb)

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Paper: physics/0606186

Date: Wed, 21 Jun 2006 16:35:20 GMT (6kb)

Date (revised v2): Thu, 22 Jun 2006 18:58:06 GMT (6kb)

Title: Alice and Bob Get Away With It: a playlet

Authors: Anthony Sudbery

Comments: 7 pages

Subj-class: Popular Physics

\\

Alice and Bob use Aravind's version of a Bell-Kochen-Specker paradox to fend

off awkward questions about what exactly they were doing in Amsterdam last

week.

\\ ( http://arXiv.org/abs/physics/0606186 , 6kb)

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Paper: cond-mat/0606592

Date: Fri, 23 Jun 2006 03:33:01 GMT (468kb)

Title: Formation of spatial shell structures in the superfluid to Mott

insulator transition

Authors: Simon Foelling, Artur Widera, Torben Mueller, Fabrice Gerbier and

Immanuel Bloch

Subj-class: Other

\\

We report on the direct observation of the transition from a compressible

superfluid to an incompressible Mott insulator by recording the in-trap density

distribution of a Bosonic quantum gas in an optical lattice. Using spatially

selective microwave transitions and spin changing collisions, we are able to

locally modify the spin state of the trapped quantum gas and record the spatial

distribution of lattice sites with different filling factors. As the system

evolves from a superfluid to a Mott insulator, we observe the formation of a

distinct shell structure, in good agreement with theory.

\\ ( http://arXiv.org/abs/cond-mat/0606592 , 468kb)

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Paper: cond-mat/0606609

Date: Fri, 23 Jun 2006 13:58:16 GMT (139kb)

Title: Quantum dynamics of Bose-Hubbard Hamiltonians beyond

Hartree-Fock-Bogoliubov: The Bogoliubov backreaction approximation

Authors: I. Tikhonenkov, J. R. Anglin, and A. Vardi

Comments: 8 pages, 7 figures

Subj-class: Other

\\

e formulate a method for studying the quantum field dynamics of ultracold

Bose gases confined within optical lattice potentials, within the lowest

Bloch-band Bose-Hubbard model. Our formalism extends the two-sites results of

Phys. Rev. Lett. {\bf86}, 000568 (2001) to the general case of $M$ lattice

sites. The methodology is based on mapping the Bose-Hubbard Hamiltonian to an

$SU(M)$ pseudospin problem and truncating the resulting hierarchy of dynamical

equations for correlation functions, up to pair-correlations between $SU(M)$

generators. Agreement with few-site exact many-particle calculations is

consistently better than the corresponding Hartree-Fock-Bogoliubov

approximation. Moreover, our approximation compares favorably with a more

elaborate two-particle irreducible effective action formalism, at a fraction of

the analytic and numerical effort.

\\ ( http://arXiv.org/abs/cond-mat/0606609 , 139kb)

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Paper: cond-mat/0606617

Date: Fri, 23 Jun 2006 17:31:07 GMT (105kb)

Title: Spatial Correlation Functions of one-dimensional Bose gases at

Equilibrium

Authors: N.P. Proukakis

Subj-class: Other; Statistical Mechanics

\\

The dependence of the three lowest order spatial correlation functions of a

harmonically confined Bose gas on temperature and interaction strength is

presented at equilibrium. Our analysis is based on a stochastic Langevin

equation for the order parameter of a weakly-interacting gas. Comparison of the

predicted first order correlation functions to those of appropriate mean field

theories demonstrates the potentially crucial role of density fluctuations on

the equilibrium coherence length. Furthermore,the change in both coherence

length and shape of the correlation function, from gaussian to exponential,

with increasing temperature is quantified. Moreover, the presented results for

higher order correlation functions are shown to be in agreeement with existing

predictions. Appropriate consideration of density-density correlations is shown

to facilitate a precise determination of quasi-condensate density profiles,

providing an alternative approach to the bimodal density fits typically used

experimentally.

\\ ( http://arXiv.org/abs/cond-mat/0606617 , 105kb)

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Paper: cond-mat/0602037

replaced with revised version Fri, 23 Jun 2006 17:10:08 GMT (158kb)

Title: Validity of the Lowest Landau Level Approximation for Rotating Bose

Gases

Authors: Alexis G. Morris and David L. Feder

Comments: Ver. 2: Minor modifications to results and text, extended discussion.

8 pages, 9 figures

Subj-class: Mesoscopic Systems and Quantum Hall Effect

\\ ( http://arXiv.org/abs/cond-mat/0602037 , 158kb)

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Paper: cond-mat/0603334

replaced with revised version Fri, 23 Jun 2006 08:18:36 GMT (30kb)

Title: Phases of Bosons or Fermions in confined optical lattices

Authors: H. Heiselberg

Comments: 6 pages, 3 figures, revised and extended

Subj-class: Superconductivity

\\ ( http://arXiv.org/abs/cond-mat/0603334 , 30kb)

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Paper: quant-ph/0606200

Date: Fri, 23 Jun 2006 16:26:49 GMT (101kb)

Title: Effective resonant transitions in quantum optical systems: kinematic and

dynamic resonances

Authors: A. B. Klimov, I. Sainz

\\

We show that quantum optical systems preserving the total number of

excitations admit a simple classification of possible resonant transitions

(including effective), which can be classified by analizying the free

Hamiltonian and the corresponding integrals of motion. Quantum systems not

preserving the total number of excitations do not admit such a simple

classification, so that an explicit form of the effective Hamiltonian is needed

to specify the allowed resonances. The structure of the resonant transitions

essentially depends on the algebraic propereties of interacting subsystems.

\\ ( http://arXiv.org/abs/quant-ph/0606200 , 101kb)

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Paper: physics/0603108

replaced with revised version Fri, 23 Jun 2006 02:02:56 GMT (247kb)

Title: Optimizing the Stark-decelerator beamline for the trapping of cold

molecules using evolutionary strategies

Authors: Joop J. Gilijamse, Jochen K\"upper, Steven Hoekstra, Sebastiaan Y. T.

van de Meerakker, Gerard Meijer

Comments: 7 pages, 4 figures (RevTeX); minor corrections (v2)

Subj-class: Instrumentation and Detectors; Accelerator Physics; Atomic Physics

Journal-ref: Phys. Rev. A 73, 063410 (2006)

DOI: 10.1103/PhysRevA.73.063410

\\ ( http://arXiv.org/abs/physics/0603108 , 247kb)

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Paper: cond-mat/0606624

Date: Fri, 23 Jun 2006 22:44:22 GMT (27kb)

Title: Asymmetric two-component Fermi gas with unequal masses

Authors: M. Iskin and C. A. R. Sa de Melo

Comments: 4 pages and 4 figures

Subj-class: Superconductivity; Other

\\

We analyze the zero temperature phase diagram for an asymmetric two-component

Fermi gas as a function of mass anisotropy and population imbalance. We

identify regions corresponding to normal, and uniform or non-uniform superfluid

phases, and find a topological quantum phase transition in the

Bardeen-Cooper-Schrieffer (BCS), unitarity and Bose-Einstein condensation (BEC)

limits. Lastly, we derive the zero temperature low frequency and long

wavelength collective excitation spectrum, and recover the Bogoliubov relation

for weakly interacting dilute bosons in the BEC limit.

\\ ( http://arXiv.org/abs/cond-mat/0606624 , 27kb)

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Paper: cond-mat/0606625

Date: Fri, 23 Jun 2006 22:56:05 GMT (470kb)

Title: Atomtronics: ultracold atom analogs of electronic devices

Authors: B. T. Seaman, M. Kraemer, D. Z. Anderson and M. J. Holland

Subj-class: Statistical Mechanics

\\

Atomtronics focuses on atom analogs of electronic materials, devices and

circuits. A strongly interacting ultracold Bose gas in a lattice potential is

analogous to electrons in solid-state crystalline media. As a consequence of

the band structure, cold atoms in a lattice can exhibit insulator or conductor

properties. P-type and N-type material analogs can be created by introducing

impurity sites into the lattice. Current through an atomtronic wire is

generated by connecting the wire to an atomtronic battery which maintains the

two contacts at different chemical potentials. The design of an atomtronic

diode with a strongly asymmetric current-voltage curve exploits the existence

of superfluid and insulating regimes in the phase diagram. The atomtronic

analog of a bipolar junction transistor exhibits large negative gain. Our

results provide the building blocks for more advanced atomtronic devices and

circuits such as amplifiers, oscillators and fundamental logic gates.

\\ ( http://arXiv.org/abs/cond-mat/0606625 , 470kb)

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\\

Paper: cond-mat/0606638

Date: Sun, 25 Jun 2006 19:17:07 GMT (138kb)

Title: A Degenerate Bose-Fermi Mixture of Metastable Atoms

Authors: J. M. McNamara, T. Jeltes, A. S. Tychkov, W. Hogervorst and W. Vassen

Comments: 4 pages, 3 figures submitted to PRL

Subj-class: Statistical Mechanics

\\

We report the observation of simultaneous quantum degeneracy in a dilute

gaseous Bose-Fermi mixture of metastable atoms. Sympathetic cooling of helium-3

(fermion) by helium-4 (boson), both in the lowest triplet state, allows us to

produce ensembles containing more than 10^6 atoms of each isotope at

temperatures below 1 micro-Kelvin, and achieve a fermionic degeneracy parameter

of T/Tf=0.45. Due to their high internal energy, the detection of individual

metastable atoms with sub-nanosecond time resolution is possible, permitting

the study of bosonic and fermionic quantum gases with unprecedented precision.

This may lead to metastable helium becoming the mainstay of quantum atom

optics.

\\ ( http://arXiv.org/abs/cond-mat/0606638 , 138kb)

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\\

Paper: cond-mat/0606642

Date: Sun, 25 Jun 2006 20:30:23 GMT (698kb)

Title: Imaging the Mott Insulator Shells using Atomic Clock Shifts

Authors: Gretchen K. Campbell, Jongchul Mun, Micah Boyd, Patrick Medley, Aaron

E. Leanhardt, Luis Marcassa, David E. Pritchard, and Wolfgang Ketterle

Subj-class: Other

\\

Microwave spectroscopy was used to probe the superfluid-Mott Insulator

transition of a Bose-Einstein condensate in a 3D optical lattice. Using density

dependent transition frequency shifts we were able to spectroscopically

distinguish sites with different occupation numbers, and to directly image

sites with occupation number n=1 to n=5 revealing the shell structure of the

Mott Insulator phase. We use this spectroscopy to determine the onsite

interaction and lifetime for individual shells.

\\ ( http://arXiv.org/abs/cond-mat/0606642 , 698kb)

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\\

Paper: cond-mat/0606654

Date: Mon, 26 Jun 2006 09:50:28 GMT (13kb)

Title: Nonequilibrium Bose systems and nonground-state Bose-Einstein

condensates

Authors: V.I. Yukalov

Comments: Latex file, 16 pages, no figures

Subj-class: Statistical Mechanics; Mesoscopic Systems and Quantum Hall Effect

Journal-ref: Laser Phys. Lett. 3 (2006) 406-414

\\

The theory of resonant generation of nonground-state Bose-Einstein

condensates is extended to Bose-condensed systems at finite temperature. The

generalization is based on the notion of representative statistical ensembles

for Bose systems with broken global gauge symmetry. Self-consistent equations

are derived describing an arbitrary nonequilibrium nonuniform Bose system. The

notion of finite-temperature topological coherent modes, coexisting with a

cloud of noncondensed atoms, is introduced. It is shown that resonant

generation of these modes is feasible for a gas of trapped Bose atoms at finite

temperature.

\\ ( http://arXiv.org/abs/cond-mat/0606654 , 13kb)

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\\\

Paper: cond-mat/0604164

replaced with revised version Mon, 26 Jun 2006 07:58:08 GMT (385kb)

Title: Fragmented condensates due to frustration of cold atoms in optical

lattices

Authors: J. J. Garcia-Ripoll, J. Pachos

Subj-class: Strongly Correlated Electrons

\\ ( http://arXiv.org/abs/cond-mat/0604164 , 385kb)

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\\

Paper: quant-ph/0606210

Date: Mon, 26 Jun 2006 07:31:14 GMT (531kb)

Title: Quantum study of information delay in electromagetically induced

transparency

Authors: Magnus T.L. Hsu, Gabriel Hetet, Oliver Glockl, Jevon J. Longdell, Ben

C. Buchler, Hans-A. Bachor, and Ping Koy Lam

Comments: 4 pages, 4 figures

\\

Using electromagnetically induced transparency (EIT), it is possible to delay

and store light in atomic ensembles. Theoretical modelling and recent

experiments have suggested that the EIT storage mechanism can be used as a

memory for quantum information. We present experiments that quantify the noise

performance of an EIT system for conjugate amplitude and phase quadratures. It

is shown that our EIT system adds excess noise to the delayed light that has

not hitherto been predicted by published theoretical modelling. In analogy with

other continuous-variable quantum information systems, the performance of our

EIT system is characterised in terms of conditional variance and signal

transfer.

\\ ( http://arXiv.org/abs/quant-ph/0606210 , 531kb)

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\\

Paper: physics/0606214

Date: Mon, 26 Jun 2006 10:09:25 GMT (90kb)

Title: Optical Lattice Polarization Effects on Hyperpolarizability of Atomic

Clock Transitions

Authors: A. V. Taichenachev and V. I. Yudin, V. D. Ovsiannikov, V. G.

Pal'chikov

Comments: 4 pages, RevTeX4, 2 eps figs

Subj-class: Atomic Physics; Optics

\\

The light-induced frequency shift due to the hyperpolarizability (i.e. terms

of second-order in intensity) is studied for a forbidden optical transition,

$J$=0$\to$$J$=0. A simple universal dependence on the field ellipticity is

obtained. This result allows minimization of the second-order light shift with

respect to the field polarization for optical lattices operating at a magic

wavelength (at which the first-order shift vanishes). We show the possibility

for the existence of a magic elliptical polarization, for which the

second-order frequency shift vanishes. The optimal polarization of the lattice

field can be either linear, circular or magic elliptical. The obtained results

could improve the accuracy of lattice-based atomic clocks.

\\ ( http://arXiv.org/abs/physics/0606214 , 90kb)

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\\

Paper: physics/0606223

Date: Mon, 26 Jun 2006 14:21:28 GMT (396kb)

Title: Tailoring of motional states in double-well potentials by time-dependent

processes

Authors: Kari Harkonen, Ollijuhani Karki, Kalle-Antti Suominen

Comments: 9 pages, 11 figures, 25 references; submitted to PRA

Subj-class: Atomic Physics

\\

We show that the vibrational state tailoring method developed for molecular

systems can be applied for cold atoms in optical lattices. The original method

is based on a three-level model interacting with two strong laser pulses in a

counterintuitive sequence [M. Rodriguez et al., Phys. Rev. A 62, 053413

(2000)]. Here we outline the conditions for achieving similar dynamics with

single time-dependent potential surfaces. It is shown that guided switching

between diabatic and adiabatic evolution has an essential role in this system.

We also show that efficient and precise tailoring of motional states in optical

lattices can be achieved, for instance, simply by superimposing two lattices

and moving them with respect to each other.

\\ ( http://arXiv.org/abs/physics/0606223 , 396kb)

------------------------------------------------------------------------------

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/ ========================================================================= 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 Tue Jun 27 2006 - 15:09:29 EST

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