Matt's arXiv selection, Wednesday 30th August 2006.

From: Matthew Davis <>
Date: Wed, 30 Aug 2006 10:37:44 +1000 (EST)

The following message was sent to the matts_arxiv list by Matthew Davis <>

Another delayed arXiv mailing this week. Next week I hope things will be back
to normal!

Home page:

The abstracts:

Paper: cond-mat/0410417
replaced with revised version Fri, 18 Aug 2006 06:53:33 GMT (544kb)

Title: Universality in Few-body Systems with Large Scattering Length
Authors: Eric Braaten (Ohio State U.), H.-W. Hammer (INT and Bonn U.)
Comments: 219 pages, 58 figures, accepted for publication in Physics Reports,
   erroneous footnote on p. 200 removed
Report-no: INT-PUB 04-27, HISKP-TH-06-07
Subj-class: Other; Soft Condensed Matter
Journal-ref: Phys.Rept. 428 (2006) 259-390
\\ ( , 544kb)
Paper: cond-mat/0602475
replaced with revised version Fri, 18 Aug 2006 14:59:22 GMT (168kb)

Title: Full quantum distribution of contrast in interference experiments
   between interacting one dimensional Bose liquids
Authors: Vladimir Gritsev, Ehud Altman, Eugene Demler, Anatoli Polkovnikov
Comments: 9 pages, 5 figures; Accepted for publication in Nature Physics
Subj-class: Strongly Correlated Electrons; Mesoscopic Systems and Quantum Hall
\\ ( , 168kb)
Paper: cond-mat/0606672
replaced with revised version Fri, 18 Aug 2006 12:37:14 GMT (15kb)

Title: Shot noise of interference between independent atomic systems
Authors: Anatoli Polkovnikov
Comments: 5 pages, 1 figure, revised version, added discussion of shot noise
   for extended systems
Subj-class: Statistical Mechanics; Disordered Systems and Neural Networks
\\ ( , 15kb)
Paper: quant-ph/0608140
Date: Fri, 18 Aug 2006 19:01:11 GMT (2402kb)

Title: 1951 Lectures on Advanced Quantum Mechanics Second Edition
Authors: Freeman J. Dyson
Comments: 149 page 10pt report class LateX document using many special
   formatting packages and including 10 EPS graphics files loaded with the
   graphicx package
   The legendary 1951 Dyson Lectures on Advanced Quantum Mechanics are finally
LaTeXed, with thorough annotations and an index as an added bonus. See the
Typist's Afterward preceding the backmatter for an explanation of this new
version, and for the historical context see the website: as well as the author's
website at the Princeton Institute for Advanced Study:
\\ ( , 2402kb)
Paper (*cross-listing*): gr-qc/0608081
Date: Thu, 17 Aug 2006 08:38:29 GMT (7kb)

Title: Optical Clocks in Space
Authors: S. Schiller, A. Goerlitz, A. Nevsky, J.C.J. Koelemeij, A. Wicht, P.
   Gill, H. A. Klein, H. S. Margolis, G. Mileti, U. Sterr, F. Riehle, E. Peik,
   Chr. Tamm, W. Ertmer, E. Rasel, V. Klein, C. Salomon, G.M. Tino, P. Lemonde,
   R. Holzwarth, T.W. Haensch
Comments: Proc. III International Conference on Particle and Fundamental
   Physics in Space (SpacePart06), Beijing 19 - 21 April 2006, to appear in
   Nucl. Phys. B
   The performance of optical clocks has strongly progressed in recent years,
and accuracies and instabilities of 1 part in 10^18 are expected in the near
future. The operation of optical clocks in space provides new scientific and
technological opportunities. In particular, an earth-orbiting satellite
containing an ensemble of optical clocks would allow a precision measurement of
the gravitational redshift, navigation with improved precision, mapping of the
earth's gravitational potential by relativistic geodesy, and comparisons
between ground clocks.
\\ ( , 7kb)
Paper: quant-ph/0606082
replaced with revised version Fri, 18 Aug 2006 18:18:26 GMT (165kb)

Title: Microwave potentials and optimal control for robust quantum gates on an
   atom chip
Authors: Philipp Treutlein, Theodor W. H\"ansch, Jakob Reichel, Antonio
   Negretti, Markus A. Cirone, Tommaso Calarco
Comments: 14 pages, 7 figures, 1 table. Published version (minor changes)
Journal-ref: Phys. Rev. A 74, 022312 (2006)
\\ ( , 165kb)
Paper: physics/0608189
Date: Fri, 18 Aug 2006 10:39:00 GMT (523kb)

Title: Detecting Neutral Atoms on an Atom Chip
Authors: M. Wilzbach, A. Haase, M. Schwarz, D. Heine, K. Wicker, X. Liu, K.-H.
   Brenner, S. Groth, Th. Fernholz, B. Hessmo, J. Schmiedmayer
Comments: 13 pages, 12 figures
Subj-class: Atomic Physics
Journal-ref: Fortschr. Phys. 54 (2006), 746 - 764
DOI: 10.1002/prop.200610323
   Detecting single atoms (qubits) is a key requirement for implementing quantum
information processing on an atom chip. The detector should ideally be
integrated on the chip. Here we present and compare different methods capable
of detecting neutral atoms on an atom chip. After a short introduction to
fluorescence and absorption detection we discuss cavity enhanced detection of
single atoms. In particular we concentrate on optical fiber based detectors
such as fiber cavities and tapered fiber dipole traps. We discuss the various
constraints in building such detectors in detail along with the current
implementations on atom chips. Results from experimental tests of fiber
integration are also described. In addition we present a pilot experiment for
atom detection using a concentric cavity to verify the required scaling.
\\ ( , 523kb)
Paper: cond-mat/0608449
Date: Mon, 21 Aug 2006 04:21:31 GMT (229kb)

Title: Investigation and comparison of multi-state and two-state atom laser
Authors: J. Dugue, N. P. Robins, C. Figl, M. Jeppesen, P. Summers, J. J. Hope
   and J. D. Close
Comments: 9 pages, 8 figures
Subj-class: Other
   We investigate the spatial structure and temporal dynamics created in a
Bose-Einstein condensate (BEC) by radio-frequency (RF) atom laser
output-couplers using a one-dimensional mean-field model. We compare the
behavior of a `pure' two-state atom laser to the multi-level systems
demonstrated in laboratories. In particular, we investigate the peak
homogeneous output flux, classical fluctuations in the beam and the onset of a
bound state which shuts down the atom laser output.
\\ ( , 229kb)
Paper: cond-mat/0608454
Date: Mon, 21 Aug 2006 09:57:11 GMT (128kb)

Title: Stability conditions and phase diagrams for two component Fermi gases
   with population imbalance
Authors: Qijin Chen, Yan He, Chih-Chun Chien, and K. Levin
Comments: 11 pages, 8 figures
Subj-class: Superconductivity; Strongly Correlated Electrons
   Superfluidity in atomic Fermi gases with population imbalance has recently
become an exciting research focus. There is considerable disagreement in the
literature about the appropriate stability conditions for states in the phase
diagram throughout the BCS to Bose-Einstein condensation (BEC) crossover. Here
we discuss these stability conditions for homogeneous polarized superfluid
phases, and compare with recent alternative proposals. The requirement of a
positive second order partial derivative of the thermodynamic potential with
respect to the fermionic excitation gap $\Delta$ (at fixed chemical potentials)
is demonstrated to be equivalent to the positive definiteness of the particle
number susceptibility matrix. In addition, we show the positivity of the
effective pair mass constitutes another nontrivial stability condition. These
conditions determine the stability of the system towards phase separation of
one form or another. We also study systematically the effects of finite
temperature and the related pseudogap on the phase diagrams defined by our
stability conditions.
\\ ( , 128kb)
Paper: cond-mat/0608455
Date: Mon, 21 Aug 2006 17:51:55 GMT (863kb)

Title: Deformation of Trapped Fermi Gases with Unequal Spin Populations
Authors: G. B. Partridge, W. Li, Y. A. Liao, R. G. Hulet, M. Haque & H. T. C.
Subj-class: Other; Superconductivity
   The formation of electron pairs, each pair consisting of a spin-up and a
spin-down electron, underlies the phenomenon of superconductivity. While the
population of each spin component is generally equal in superconductors, an
imbalance is readily produced in experiments with gases of trapped, ultracold
fermionic atoms, as was recently demonstrated. Exotic new states of matter are
predicted for the unbalanced system that, if realized, may have important
implications for our understanding of nuclei, compact stars, and quantum
chromodynamics. We previously reported evidence for a phase separation in a
strongly-interacting two-component Fermi gas to a state containing a paired
central core, with the excess unpaired atoms residing outside this core. We
show here that the real-space distributions of the gas deform markedly with
increasing imbalance in order to produce a core that is uniformly paired. These
deformations are inconsistent with local space isotropy as embodied by the
local-density approximation (LDA). The breakdown of the LDA is surprising as
the correlation length is small compared with the characteristic size of the
gas. A possible explanation, considered here, is that an anisotropic nematic
ordering develops. The observed violations of the LDA may be facilitated by the
high aspect ratio trapping geometry employed in the experiment. We find that
these deformations can be suppressed at higher temperature.
\\ ( , 863kb)
Paper: physics/0608060
Date: Sat, 5 Aug 2006 10:27:45 GMT (412kb)

Title: Matter-wave soliton control in optical lattices with topological
Authors: Yaroslav V. Kartashov, Lluis Torner
Comments: 15 pages, 4 figures, to appear in Physical Review A
Subj-class: Optics; Materials Science
   We address the concept of guiding and transporting matter-wave solitons along
the channels of optical lattices made by interference patterns of beams
containing topological wavefront dislocations. The local lattice distortions
that occur around the dislocations cause solitons to move along reconfigurable
paths, a phenomenon that may be used for controlled all-optical manipulation of
Bose-Einstein condensates. Multiple dislocations form traps that can capture
and hold moving solitons.
\\ ( , 412kb)
Paper: cond-mat/0604557
replaced with revised version Fri, 18 Aug 2006 23:06:10 GMT (140kb)

Title: Stable Skyrmions in spinor condensates
Authors: Igor F. Herbut and Masaki Oshikawa
Comments: 4 pages, 2 figures; few typos corrected, references updated, to
   appear in Phys. Rev. Lett
Subj-class: Superconductivity; Statistical Mechanics; Pattern Formation and
\\ ( , 140kb)
Paper: cond-mat/0604558
replaced with revised version Mon, 21 Aug 2006 17:19:59 GMT (946kb)

Title: Phase diagram of a polarized Fermi gas across a Feshbach resonance in a
   potential trap
Authors: W. Yi and L.-M. Duan
Comments: 9 pages, 4 figures
Subj-class: Other
Journal-ref: Phys. Rev. A. 74, 013610 (2006)
DOI: 10.1103/PhysRevA.74.013610
\\ ( , 946kb)
Paper: cond-mat/0607361
replaced with revised version Mon, 21 Aug 2006 07:34:56 GMT (101kb)

Title: Collective excitations of a Bose-Einstein condensate in an anharmonic
Authors: Guan-Qiang Li, Li-Bin Fu, Ju-Kui Xue, Xu-Zong Chen, and Jie Liu
Comments: 5 pages, 4 figures
Subj-class: Mesoscopic Systems and Quantum Hall Effect
\\ ( , 101kb)
Paper: cond-mat/0607453
replaced with revised version Mon, 21 Aug 2006 15:43:28 GMT (48kb)

Title: Orthogonality catastrophe and shock waves in a non-equilibrium Fermi gas
Authors: E. Bettelheim, A. G. Abanov, and P. Wiegmann
Comments: 5 pages, 1 figure, revtex4, prl
Subj-class: Strongly Correlated Electrons; Mesoscopic Systems and Quantum Hall
\\ ( , 48kb)
Paper: quant-ph/0608158
Date: Mon, 21 Aug 2006 15:49:45 GMT (88kb)

Title: How much entanglement can be generated between two atoms by detecting
Authors: L. Lamata, J.J. Garcia-Ripoll, J.I. Cirac
Comments: 4 pages, 3 figures
   It is possible to achieve an arbitrary amount of entanglement between two
atoms using only spontaneously emitted photons, linear optics, single photon
sources and projective measurements. This is in contrast to all current
experimental proposals for entangling two atoms, which are fundamentally
restricted to one ebit.
\\ ( , 88kb)
Paper: physics/0608200
Date: Sat, 19 Aug 2006 00:13:49 GMT (250kb)

Title: Cold collisions of OH and Rb. I: the free collision
Authors: Manuel Lara, John L. Bohn, Daniel E. Potter, Pavel Sold\'an and Jeremy
   M. Hutson
Comments: 20 pages, 16 figures
Subj-class: Atomic Physics; Chemical Physics
   We have calculated elastic and state-resolved inelastic cross sections for
cold and ultracold collisions in the Rb($^1 S$) + OH($^2 \Pi_{3/2}$) system,
including fine-structure and hyperfine effects. We have developed a new set of
five potential energy surfaces for Rb-OH($^2 \Pi$) from high-level {\em ab
initio} electronic structure calculations, which exhibit conical intersections
between covalent and ion-pair states. The surfaces are transformed to a
quasidiabatic representation. The collision problem is expanded in a set of
channels suitable for handling the system in the presence of electric and/or
magnetic fields, although we consider the zero-field limit in this work.
Because of the large number of scattering channels involved, we propose and
make use of suitable approximations. To account for the hyperfine structure of
both collision partners in the short-range region we develop a
frame-transformation procedure which includes most of the hyperfine
Hamiltonian. Scattering cross sections on the order of $10^{-13}$ cm$^2$ are
predicted for temperatures typical of Stark decelerators. We also conclude that
spin orientation of the partners is completely disrupted during the collision.
Implications for both sympathetic cooling of OH molecules in an environment of
ultracold Rb atoms and experimental observability of the collisions are
\\ ( , 250kb)
Paper: cond-mat/0608472
Date: Tue, 22 Aug 2006 10:05:42 GMT (20kb)

Title: Conserving Gapless Mean-Field Theory of a Multi-Component Bose-Einstein
Authors: Yoshiyuki Kondo, Takafumi Kita
Comments: 7 pages, 7 figures
Subj-class: Statistical Mechanics
   We develop a mean-field theory for Bose-Einstein condensation of spin-1 atoms
with internal degrees of freedom. It is applicable to nonuniform systems at
finite temperatures with a plausible feature of satisfying the Hugenholtz-Pines
theorem and various conservation laws simultaneously. Using it, we clarify
thermodynamic properties and the excitation spectra of a uniform gas. The
condensate is confirmed to remain in the same internal state from T=0 up to
$T_{c}$ for both antiferromagnetic and ferromagnetic interactions. The
excitation spectra of the antiferromagnetic (ferromagnetic) interaction are
found to have only a single gapless mode, contrary to the prediction of the
Bogoliubov theory where three (two) of them are gapless.
\\ ( , 20kb)
Paper: cond-mat/0608477
Date: Tue, 22 Aug 2006 14:11:48 GMT (44kb)

Title: NNLO epsilon expansion for a Fermi gas at infinite scattering length
Authors: Peter Arnold, Joaquin E. Drut, and Dam Thanh Son
Comments: 26 pages, 14 figures
Report-no: INT PUB 06-12
Subj-class: Other
   We extend previous work on applying the epsilon-expansion to universal
properties of a cold, dilute Fermi gas in the unitary regime of infinite
scattering length. We compute the ratio xi = mu/epsilon_F of chemical potential
to ideal gas Fermi energy to next-to-next-to-leading order (NNLO) in
epsilon=4-d, where d is the number of spatial dimensions. We also explore the
nature of corrections from the order after NNLO.
\\ ( , 44kb)
Paper: cond-mat/0608491
Date: Tue, 22 Aug 2006 19:56:06 GMT (310kb)

Title: Supersolids in Confined Fermions on One-Dimensional Optical Lattices
Authors: F. Karim Pour, M. Rigol, S. Wessel, A. Muramatsu
Comments: 4 pages, 4 figures
Subj-class: Strongly Correlated Electrons; Superconductivity
   Using quantum Monte Carlo simulations, we show that density-density and
pairing correlation functions of the one-dimensional attractive fermionic
Hubbard model in a harmonic confinement potential are characterized by the
anomalous dimension $K_\rho$ of a corresponding periodic system. This allows to
determine conditions for a supersolid state inside a harmonic trap. We show
explicitely, that under such conditions the structure form factors for both
correlation functions diverge with the same exponent upon increasing the system
size, thus giving rise to a (quasi-)supersolid.
\\ ( , 310kb)
Paper: cond-mat/0607334
replaced with revised version Tue, 22 Aug 2006 09:24:29 GMT (63kb)

Title: Bragg Spectroscopy of Cold Atomic Fermi Gases
Authors: G. M. Bruun, Gordon Baym
Comments: 8 pages, 9 figures
Subj-class: Superconductivity
\\ ( , 63kb)
Paper: quant-ph/0508185
replaced with revised version Tue, 22 Aug 2006 10:27:38 GMT (10kb)

Title: Dynamic response of interacting one-dimensional fermions in the harmonic
   atom trap: Phase response and the inhomogeneous mobility
Authors: W. Wonneberger
Comments: 16 pages, LaTex, changed content
Journal-ref: Physics Letters A 356 (2006) 272-276
\\ ( , 10kb)
Paper: cond-mat/0608501
Date: Wed, 23 Aug 2006 08:56:31 GMT (47kb)

Title: Reply to Comment on "Superfluid stability in the BEC-BCS crossover" by
   Sheehy and Radzihovsky
Authors: C.-H. Pao, S.-T. Wu and S.-K. Yip
Comments: 6 pages, 1 figure
Subj-class: Superconductivity; Strongly Correlated Electrons
   The reason behind the discrepancy between the phase diagrams of our earlier
work [1] and the comment of Sheehy and Radzihovsky [2] is discussed. We show
that, in contrast to what is claimed in [2], the requirement of positive
susceptibility is sufficient to rule out states that are local maximum of the
free energy (as a function of the order parameter $\Delta$
\\ ( , 47kb)
Paper: quant-ph/0608177
Date: Wed, 23 Aug 2006 12:57:39 GMT (11kb)

Title: Fermionic coherent states for pseudo-Hermitian two-level Systems
Authors: O. Cherbal, M. Drir, M. Maamache, and D.A. Trifonov
Comments: 13 pages (Latex, article class), no figures
   We introduce creation and annihilation operators of pseudo-Hermitian fermions
for two-level systems described by pseudo-Hermitian Hamiltonian with real
eigenvalues. This allows the generalization of the fermionic coherent states
approach to such systems. Pseudo-fermionic coherent states are constructed as
eigenstates of two pseudo-fermion annihilation operators. These coherent states
form a bi-normal and bi-overcomplete system, and their evolution governed by
the pseudo-Hermitian Hamiltonian is temporally stable. In terms of the
introduced pseudo-fermion operators the two-level system' Hamiltonian takes a
factorized form similar to that of a harmonic oscillator.
\\ ( , 11kb)
Paper: quant-ph/0608182
Date: Wed, 23 Aug 2006 18:15:27 GMT (269kb)

Title: Quantum phase gate and controlled entanglement with polar molecules
Authors: Eric Charron (PPM), P\'{e}rola Milman (PPM, CERMICS), Arne Keller
   (PPM), Osman Atabek (PPM)
Proxy: ccsd ccsd-00089723
   We propose an alternative scenario for the generation of entanglement between
rotational quantum states of two polar molecules. This entanglement arises from
dipole-dipole interaction, and is controlled by a sequence of laser pulses
simultaneously exciting both molecules. We study the efficiency of the process,
and discuss possible experimental implementations with cold molecules trapped
in optical lattices or in solid matrices. Finally, various entanglement
detection procedures are presented, and their suitability for these two
physical situations is analyzed.
\\ ( , 269kb)
Paper: quant-ph/0608002
replaced with revised version Wed, 23 Aug 2006 12:03:03 GMT (11kb)

Title: Relation between quantum tunneling times for bosons
Authors: C.A. Bonin, J.T. Lunardi, L.A. Manzoni, and B.M. Pimentel
Comments: 4 pages, no figures. It was added the new reference [6] and a
   corresponding note in the Introduction. To appear in Phys. Rev. A - Brief
\\ ( , 11kb)
Paper: cond-mat/0608522
Date: Thu, 24 Aug 2006 02:32:00 GMT (720kb)

Title: Thermodynamics of quantum degenerate gases in optical lattices
Authors: P. B. Blakie, A.-M. Rey, and A. Bezett
Comments: 6 pages, 4 figures. Submitted to proceedings of Laser Physics 2006
Subj-class: Statistical Mechanics
   The entropy-temperature curves are calculated for non-interacting Bose and
Fermi gases in a 3D optical lattice. These curves facilitate understanding of
how adiabatic changes in the lattice depth affect the temperature, and we
demonstrate regimes where the atomic sample can be significantly heated or
cooled by the loading process. We assess the effects of interactions on a Bose
gas in a deep optical lattice, and show that interactions ultimately limit the
extent of cooling that can occur during lattice loading.
\\ ( , 720kb)
Paper: cond-mat/0608532
Date: Thu, 24 Aug 2006 11:24:19 GMT (197kb)

Title: Dynamical stability of a doubly quantized vortex in a three-dimensional
Authors: Emil Lundh, Halvor M. Nilsen
Comments: 23 pages, 11 figures
Subj-class: Other
   The Bogoliubov equations are solved for a three-dimensional Bose-Einstein
condensate containing a doubly quantized vortex, trapped in a harmonic
potential. Complex frequencies, signifying dynamical instability, are found for
certain ranges of parameter values. The existence of alternating windows of
stability and instability, respectively, is explained qualitatively and
quantitatively using variational calculus and direct numerical solution. It is
seen that the windows of stability are much smaller for a cigar shaped
condensate than for a pancake shaped one, which is consistent with the findings
of recent experiments.
\\ ( , 197kb)
Paper: cond-mat/0608542
Date: Thu, 24 Aug 2006 19:48:57 GMT (159kb)

Title: Three-body recombination in a cesium gas at ultralow temperatures
Authors: M.T. Yamashita, T. Frederico and Lauro Tomio
Subj-class: Soft Condensed Matter
   We calculate the three-body recombination length of cesium atoms to deeply
bound molecules up to 500 nK. We include the effects of triatomic continuum
resonances for large negative scattering lengths ($a$) and positive energies
generalizing the recombination rate equation for finite temperatures. We
calculate the position and width of the continuum resonances near the Feshbach
resonance for the experimental setup [T. Kraemer et al., Nature {\bf 440}, 315
(2006)]. Our results give a good quantitative description of the experimental
recombination length as a function of $a$ and the trap temperature, $T$, with
no new free parameters. The increase of $T$ moves the resonance peak of the
three-body recombination rate to lower values of $|a|$ exhibiting a saturation
behavior, this result is consistent with the experimental data.
\\ ( , 159kb)
Paper: cond-mat/0603639
replaced with revised version Thu, 24 Aug 2006 04:27:19 GMT (11kb)

Title: Resonance reactions and enhancement of weak interactions in collisions
   of cold molecules
Authors: V.V. Flambaum, J.S.M. Ginges
Comments: 5 pages. Included discussion of expected size of effects
Subj-class: Other; Chemical Physics; Atomic Physics
Journal-ref: Phys. Rev. A 74 (2006) 025601
\\ ( , 11kb)
Paper: quant-ph/0601137
replaced with revised version Thu, 24 Aug 2006 07:43:20 GMT (466kb)

Title: Theoretical study of a cold atom beam splitter
Authors: Naceur Gaaloul (PPM, LSAMA), Annick Suzor-Weiner (PPM), Laurence
   Pruvost (LAC), Mourad Telmini (LSAMA), Eric Charron (PPM)
Proxy: ccsd ccsd-00017414
\\ ( , 466kb)
Paper: physics/0608233
Date: Thu, 24 Aug 2006 13:37:17 GMT (68kb)

Title: Cooling and trapping of ultra-cold strontium isotopic mixtures
Authors: N. Poli, R. E. Drullinger, G. Ferrari, J. Leonard, F. Sorrentino, and
   G. M. Tino
Subj-class: Atomic Physics
Journal-ref: Phys. Rev. A 71, 061403(R) (2005)
DOI: 10.1103/PhysRevA.71.061403
   We present the simultaneous cooling and trapping of an isotopic mixture in a
magneto-optical trap and we describe the transfer of the mixture into a
conservative, far-off resonant dipole trap. The mixture is prepared with a new
technique that applies to intermediate and heavy alkaline earth like atoms. In
this work, 88Sr and 86Sr are simultaneously loaded first into the
magneto-optical trap operated on the 1S0-3P1 spin-forbidden line at 689 nm, and
then transferred into the dipole trap. We observe fast inter-species
thermalization in the dipole trap which allows one to set a lower bound on the
88Sr-86Sr elastic cross section.
\\ ( , 68kb)
Paper: physics/0608235
Date: Thu, 24 Aug 2006 15:18:12 GMT (252kb)

Title: Is it possible to observe experimentally a metal-insulator transition in
   ultra cold atoms?
Authors: Antonio M. Garcia-Garcia, Jiao Wang
Comments: 7 pages, 3 figures
Subj-class: Atomic Physics
   Kicked rotors with certain non-analytic potentials avoid dynamical
localization and undergo a metal-insulator transition. We show that typical
properties of this transition are still present as the non-analyticity is
progressively smoothed out provided that the smoothing is less than a certain
limiting value. We have identified a smoothing dependent time scale such that
full dynamical localization is absent and the quantum momentum distribution
develops power-law tails with anomalous decay exponents as in the case of a
conductor at the metal-insulator transition. We discuss under what conditions
these findings may be verified experimentally by using ultra cold atoms
techniques. It is found that ultra-cold atoms can indeed be utilized for the
experimental investigation of the metal-insulator transition.
\\ ( , 252kb)
Paper: physics/0604082
replaced with revised version Tue, 22 Aug 2006 23:33:31 GMT (231kb)

Title: Atom interferometer as a selective sensor of rotation or gravity
Authors: B. Dubetsky and M. A. Kasevich
Comments: 21 pages, 4 figures, extended references, discussion, and motivation
Subj-class: Atomic Physics
Journal-ref: Phys. Rev. A 74, 023615 (2006)
\\ ( , 231kb)
Paper: cond-mat/0608553
Date: Fri, 25 Aug 2006 09:07:40 GMT (103kb)

Title: Ultracold atomic quantum gases far from equilibrium
Authors: T. Gasenzer, J. Berges, M.G. Schmidt, and M. Seco
Comments: 4 pages, SEWM06 proceedings
Subj-class: Other
   We calculate the time evolution of a far-from-equilibrium initial state of a
non-relativistic ultracold Bose gas in one spatial dimension. The
non-perturbative approximation scheme is based on a systematic expansion of the
two-particle irreducible effective action in powers of the inverse number of
field components. This yields dynamic equations which contain direct
scattering, memory and off-shell effects that are not captured in mean-field
\\ ( , 103kb)
Paper: cond-mat/0608566
Date: Fri, 25 Aug 2006 18:01:43 GMT (653kb)

Title: Excitations from a Bose-Einstein condensate of magnons in coupled spin
Authors: V. O. Garlea, A. Zheludev, T. Masuda, H. Manaka, J.-H. Chung, Y. Qiu,
   K. Habicht, K. Kiefer
Comments: 11 pages, 3 figures
Subj-class: Strongly Correlated Electrons; Superconductivity
   Field-induced transitions in quantum magnets can often be interpreted in
terms of Bose-Eistein condensation (BEC) of magnons. Such transitions are fully
equivalent to BEC of atoms in liquid He, laser-cooled gasses in magnetic traps,
or Cooper pairs in superconductors. An interesting conundrum is presented by
BEC of magnons in weakly interacting gapped quantum spin chains or ladders.
Here the disordered ``spin liquid'' normal state is a unique property of
1-dimensional (1D) topology. In contrast, the stability of the magnon
condensate at high fields is necessarily a 3D effect, and relies on residual
inter-chain interactions. The phenomenon is therefore one of the more striking
examples of dimensional crossover in many-body quantum mechanics. Do the
topology and one-dimensionality of the normal state influence in the properties
of the condensate? Below we answer this question experimentally, through a
study of field-induced BEC and relevant collective excitations in a
prototypical spin ladder material.
\\ ( , 653kb)
Paper: cond-mat/0603030
replaced with revised version Thu, 24 Aug 2006 21:44:38 GMT (24kb)

Title: The Mott insulator phase of the one dimensional Bose-Hubbard model: a
   high order perturbative study
Authors: Bogdan Damski and Jakub Zakrzewski
Comments: 7 pages, 4 figures, 1 table. Significantly expanded version with
   respect to former submission (to appear in Phys. Rev. A)
Report-no: LAUR-06-1357
Subj-class: Other
\\ ( , 24kb)
Paper: quant-ph/0608197
Date: Fri, 25 Aug 2006 09:05:11 GMT (40kb)

Title: Matrix Product State Representations
Authors: D. Perez-Garcia, F. Verstraete, M.M. Wolf, J.I. Cirac
   This work gives a detailed investigation of matrix product state (MPS)
representations for multipartite quantum states. We determine the freedom in
representations with and without translation symmetry, derive respective
canonical forms and provide efficient methods for obtaining them. Results on
frustration free Hamiltonians and the generation of MPS are extended, and the
use of the MPS-representation for classical simulations of quantum systems is
\\ ( , 40kb)
Paper: physics/0603145
replaced with revised version Fri, 25 Aug 2006 16:55:47 GMT (473kb)

Title: Slow Light Propagation in a Linear-Response Three-Level Atomic Vapor
Authors: Wenhai Ji, Chunbai Wu and M. G. Raymer
Comments: 21 pages, 8 figures. submitted to JOSAB
Subj-class: Optics
\\ ( , 473kb)
Paper: cond-mat/0608571
Date: Fri, 25 Aug 2006 21:02:24 GMT (251kb)

Title: Bosonic molecules in rotating traps
Authors: Igor Romanovsky, Constantine Yannouleas, Leslie O. Baksmaty, Uzi
Comments: To appear in Phys. Rev. Lett. LATEX, 5 pages with 5 figures. For
   related papers, see
Subj-class: Soft Condensed Matter; Mesoscopic Systems and Quantum Hall Effect
   We present a variational many-body wave function for repelling bosons in
rotating traps, focusing on rotational frequencies that do not lead to
restriction to the lowest Landau level. This wave function incorporates
correlations beyond the Gross-Pitaevskii (GP) mean field approximation, and it
describes rotating boson molecules (RBMs) made of localized bosons that form
polygonal-ring-like crystalline patterns in their intrinsic frame of reference.
The RBMs exhibit characteristic periodic dependencies of the ground-state
angular momenta on the number of bosons in the polygonal rings. For small
numbers of neutral bosons, the RBM ground-state energies are found to be always
lower than those of the corresponding GP solutions, in particular in the regime
of GP vortex formation.
\\ ( , 251kb)
Paper: cond-mat/0608585
Date: Sun, 27 Aug 2006 00:01:35 GMT (936kb)

Title: Long Phase Coherence Time and Number Squeezing of two Bose-Einstein
   Condensates on an Atom Chip
Authors: G.-B. Jo, Y. Shin, S. Will, T. A. Pasquini, M. Saba, W. Ketterle, D.
   E. Pritchard, M. Vengalattore, and M. Prentiss
Subj-class: Other
   We measured the relative phase of two Bose-Einstein condensates confined in
an radio frequency induced double well potential on an atom chip. We observed
phase coherence between the separated condensates for times up to 200 ms after
splitting, a factor of 10 beyond the phase diffusion limit expected for a
coherent state in our experimental conditions (20 ms). The enhanced coherence
time is attributed to number squeezing of the initial state by a factor of 10.
In addition, we demonstrated a rotationally sensitive (Sagnac) geometry for a
guided atom interferometer by propagating the split condensates.
\\ ( , 936kb)
Paper: cond-mat/0608602
Date: Mon, 28 Aug 2006 14:16:25 GMT (8kb)

Title: The Bose Gas Low Momentum Limit Revisited
Authors: H. Perez Rojas and D. Oliva
Comments: 5 pages, RevTex 4
Subj-class: Statistical Mechanics; Superconductivity
   We discuss the standard approach to the problem of the low momentum limit of
the spectrum for a weakly interacting Bose gas. The Bogoliubov's spectrum is
shown to be obtained as a Goldstone mode thanks to the introduction of a
chemical potential $\mu$. This procedure has, however, difficulties since the
breaking of the gauge symmetry implies that the corresponding chemical
potential must be taken as zero, unless it is introduced before breaking the
symmetry. But if this is done, after the symmetry breaking $\mu$ loses its
meaning as a chemical potential. An alternative two-mode solution is suggested
having two modes, one of them being the free-particle quadratic in momentum
spectrum, the second bearing a gap. This gap leads to a $\lambda$-type behavior
of the specific heat near the critical temperature.
\\ ( , 8kb)
Paper: cond-mat/0506766
replaced with revised version Mon, 28 Aug 2006 10:06:14 GMT (234kb)

Title: Quantum lattice solitons in ultracold bosons near Feshbach resonance
Authors: K.V.Krutitsky and D.V.Skryabin
Subj-class: Other
Journal-ref: J. Phys. B 39, 3507-3517 (2006)
DOI: 10.1088/0953-4075/39/17/008
\\ ( , 234kb)
Paper: cond-mat/0604572
replaced with revised version Mon, 28 Aug 2006 09:24:39 GMT (80kb)

Title: Resonant pairing between Fermions with unequal masses
Authors: S.-T. Wu, C.-H. Pao and S.-K. Yip
Comments: 10 pages, 4 figures
Subj-class: Superconductivity; Other
\\ ( , 80kb)
Paper: cond-mat/0605335
replaced with revised version Mon, 28 Aug 2006 07:58:02 GMT (214kb)

Title: Ultracold polarized Fermi gas at intermediate temperatures
Authors: Jani-Petri Martikainen
Comments: Final published version
Subj-class: Statistical Mechanics
Journal-ref: Phys. Rev. A 74, 013602 (2006)
\\ ( , 214kb)
Paper: cond-mat/0606697
replaced with revised version Mon, 28 Aug 2006 05:23:11 GMT (331kb)

Title: Fermionic atoms trapped in one-dimensional optical superlattice with
   harmonic confinement
Authors: Takanori Yamashita, Norio Kawakami, Makoto Yamashita
Comments: 8 pages, 9 figures, revised version, figures rearranged
Subj-class: Statistical Mechanics
\\ ( , 331kb)
Paper: quant-ph/0608210
Date: Mon, 28 Aug 2006 08:32:01 GMT (260kb)

Title: Multi-dark-state resonances in cold multi-Zeeman-sublevel atoms
Authors: Bo Wang, Yanxu Han, Jintao Xiao, Xudong Yang, Changde Xie, Hai Wang,
   Min Xiao
Comments: 11pages, 4figures
   We present our experimental and theoretical studies of multi-dark-state
resonances (MDSRs) generated in a unique cold rubidium atomic system with only
one coupling laser beam. Such MDSRs are caused by different transition
strengths of the strong coupling beam connecting different Zeeman sublevels.
Controlling the transparency windows in such electromagnetically induced
transparency system can have potential applications in multi-wavelength optical
communication and quantum information processing.
\\ ( , 260kb)
Paper: quant-ph/0608214
Date: Mon, 28 Aug 2006 12:33:59 GMT (110kb)

Title: Quantum sensitivity limit of a Sagnac hybrid interferometer based on
   slow-light propagation in ultra-cold gases
Authors: F. E. Zimmer, M. Fleischhauer
Comments: 12 pages, 6 figures
   The light--matter-wave Sagnac interferometer based on ultra-slow light
proposed recently in (Phys. Rev. Lett. 92, 253201 (2004)) is analyzed in
detail. In particular the effect of confining potentials is examined and it is
shown that the ultra-slow light attains a rotational phase shift equivalent to
that of a matter wave, if and only if the coherence transfer from light to
atoms associated with slow light is associated with a momentum transfer and if
an ultra-cold gas in a ring trap is used. The quantum sensitivity limit of the
Sagnac interferometer is determined and the minimum detectable rotation rate
calculated. It is shown that the slow-light interferometer allows for a
significantly higher signal-to-noise ratio as possible in current matter-wave
\\ ( , 110kb)
Paper: quant-ph/0508135
replaced with revised version Mon, 28 Aug 2006 16:54:32 GMT (36kb)

Title: Superradiance in ultracold Rydberg gases
Authors: Tun Wang, S. F. Yelin, R. Cote, E. E. Eyler, S. M. Farooqi, P. L.
   Gould, M. Kostrun, D. Tong, D. Vrinceanu
Comments: 4 pages, 4 figures
\\ ( , 36kb)

Till next time,

Dr M. J. Davis,               Senior Lecturer in Physics
School of Physical Sciences,  email:
University of Queensland,     ph   : +61 7 334 69824
Brisbane, QLD 4072,           fax  : +61 7 336 51242
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Received on Wed Aug 30 2006 - 10:37:44 EST

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