Matt's arXiv selection: week ending 5th January 2007.

From: Matthew Davis <>
Date: Thu, 11 Jan 2007 14:38:06 +1000 (EST)

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

It's been a slow start to the year for me, and thankfully for the arXiv as well.
This week there are only 12 new papers and 8 replacements.

Yesterday the 299th subscriber signed up to this list....

Paper: cond-mat/0612685
Date: Fri, 29 Dec 2006 01:21:12 GMT (147kb)

Title: High-Resolution Magnetometry with a Spinor Bose-Einstein Condensate
Authors: M. Vengalattore, J. M. Higbie, S. R. Leslie, J. Guzman, L. E. Sadler
   and D. M. Stamper-Kurn
Categories: cond-mat.other
Subj-class: Other
   We demonstrate a precision magnetic microscope based on direct imaging of the
Larmor precession of a $^{87}$Rb spinor Bose-Einstein condensate. This
magnetometer attains a field sensitivity of 8.3 pT/Hz$^{1/2}$ over a
measurement area of 120 $\mu$m$^2$, an improvement over the low-frequency field
sensitivity of modern SQUID magnetometers. The corresponding atom shot-noise
limited sensitivity is estimated to be 0.15 pT/Hz$^{1/2}$ for unity duty cycle
measurement. The achieved phase sensitivity is close to the atom shot-noise
limit suggesting possibilities of spatially resolved spin-squeezed
magnetometry. This magnetometer marks a significant application of degenerate
atomic gases to metrology.
\\ ( , 147kb)
Paper: cond-mat/0701005
Date: Sat, 30 Dec 2006 07:24:38 GMT (79kb)

Title: Effective Field Theory for Light in Disordered Atomic Medium
Authors: M.B. Smirnov, M.A. Baranov
Categories: cond-mat.other cond-mat.dis-nn
Comments: 22 pages, 1 figure
Subj-class: Other; Disordered Systems and Neural Networks
   We develop a field theory approach to light propagation in a gas of resonant
atoms taking into account vector character of light and atom-atom interactions.
Within this approach, we calculate the propagator of the electric field for
both short and long-range density-density correlation functions of the gas.
\\ ( , 79kb)
Paper: cond-mat/0701028
Date: Mon, 1 Jan 2007 23:21:35 GMT (749kb)

Title: Observation of Faraday Waves in a Bose-Einstein Condensate
Authors: P. Engels, C. Atherton, M. A. Hoefer
Categories: cond-mat.other
Comments: 4 pages, 5 figures
Subj-class: Other
   Faraday waves in a cigar-shaped Bose-Einstein condensate are created. It is
shown that periodically modulating the transverse confinement, and thus the
nonlinear interactions in the BEC, excites small amplitude longitudinal
oscillations through a parametric resonance. It is also demonstrated that even
without the presence of a continuous drive, an initial transverse breathing
mode excitation of the condensate leads to spontaneous pattern formation in the
longitudinal direction. Finally, the effects of strongly driving the transverse
breathing mode with large amplitude are investigated. In this case,
impact-oscillator behavior and intriguing nonlinear dynamics, including the
gradual emergence of multiple longitudinal modes, are observed.
\\ ( , 749kb)
Paper: quant-ph/0701008
Date: Tue, 2 Jan 2007 09:57:57 GMT (371kb)

Title: Theory of Dicke narrowing in coherent population trapping
Authors: O. Firstenberg, M. Shuker, A. Ben-Kish, D. R. Fredkin, N. Davidson, A.
Categories: quant-ph
Comments: 6 pages, 2 figures
   The Doppler effect is one of the dominant broadening mechanisms in thermal
vapor spectroscopy. For two-photon transitions one would naively expect the
Doppler effect to cause a residual broadening, proportional to the wave-vector
difference. In coherent population trapping (CPT), which is a narrow-band
phenomenon, such broadening was not observed experimentally. This has been
commonly attributed to frequent velocity-changing collisions, known to narrow
Doppler-broadened one-photon absorption lines (Dicke narrowing). Here we show
theoretically that such a narrowing mechanism indeed exists for CPT resonances.
The narrowing factor is the ratio between the atom's mean free path and the
wavelength associated with the wave-vector difference of the two radiation
fields. A possible experiment to verify the theory is suggested.
\\ ( , 371kb)
Paper: physics/0701003
Date: Fri, 29 Dec 2006 23:04:02 GMT (407kb)

Title: Coherent Slowing of a Supersonic Beam with an Atomic Paddle
Authors: E. Narevicius, A. Libson, M.F. Riedel, C.G. Parthey, I. Chavez, U.
   Even, and M.G. Raizen
Categories: physics.atom-ph
Subj-class: Atomic Physics
   We report the slowing of a supersonic beam by elastic reflection from a
receding atomic mirror. We use a pulsed supersonic nozzle to generate a 511 +/-
9 m/s beam of helium that we slow by reflection from a Si(111)-H(1x1) crystal
placed on the tip of a spinning rotor. We were able to reduce the velocity of
helium by 246 m/s and show that the temperature of the slowed beam is lower
than 250 mK in the co-moving frame.
\\ ( , 407kb)
Paper: physics/0701018
Date: Sun, 31 Dec 2006 18:46:21 GMT (60kb)

Title: Atom interferometry using wavepackets with constant spatial separations
Authors: Edward J. Su, Saijun Wu, Mara Prentiss
Categories: physics.atom-ph
Subj-class: Atomic Physics
   We demonstrate a standing wave light pulse sequence that places atoms into a
superposition of displaced wavepackets with precisely controlled separations
that remain constant for times as long as 1 s. The separated wavepackets are
subsequently recombined resulting in atom interference patterns that probe
energy differences of approximately 10^-34 J, and can provide acceleration
measurements that are insensitive to platform vibrations.
\\ ( , 60kb)
Paper: physics/0701023
Date: Tue, 2 Jan 2007 10:40:09 GMT (563kb)

Title: Influence of lasers propagation delay on the sensitivity of atom
Authors: J. Le Gou\"et, P. Cheinet, J. Kim, D. Holleville, A. Clairon, A.
   Landragin, F. Pereira Dos Santos
Categories: physics.atom-ph
Comments: 17 pages, 6 figures
Subj-class: Atomic Physics
   In atom interferometers based on two photon transitions, the delay induced by
the difference of the laser beams paths makes the interferometer sensitive to
the fluctuations of the frequency of the lasers. We first study, in the general
case, how the laser frequency noise affects the performance of the
interferometer measurement. Our calculations are compared with the measurements
performed on our cold atom gravimeter based on stimulated Raman transitions. We
finally extend this study to the case of cold atom gradiometers.
\\ ( , 563kb)
Paper: cond-mat/0701044
Date: Tue, 2 Jan 2007 22:48:27 GMT (280kb)

Title: Dynamics of the BCS-BEC crossover from a few-body perspective
Authors: Javier von Stecher, Chris H. Greene
Categories: cond-mat.supr-con
Comments: 5 pages, 3 figures
Subj-class: Superconductivity
   The spectrum of two spin-up and two spin-down fermions in a trap is
calculated using a correlated gaussian basis throughout the range of the
BCS-BEC crossover. The solutions are used to calculate the time-evolution of
the system as the scattering length is changed, mimicking experiments with
Fermi gases near Fano-Feshbach resonances. The dynamics of the system can be
understood as a sequence of Landau-Zener transitions. Finally, we propose a
ramping scheme to study atom-molecule coherence and we study molecular
conversion efficiency from a two-body picture.
\\ ( , 280kb)
Paper: cond-mat/0701050
Date: Wed, 3 Jan 2007 12:55:24 GMT (80kb)

Title: Crossover dark soliton dynamics in ultracold one-dimensional Bose gases
Authors: D.J. Frantzeskakis, P.G. Kevrekidis and N.P. Proukakis
Categories: cond-mat.other
Comments: To appear in Phys. Lett. A
Subj-class: Other
   Ultracold confined one-dimensional atomic gases are predicted to support dark
soliton solutions arising from a nonlinear Schr\"{o}dinger equation of suitable
nonlinearity. In weakly-interacting (high density) gases, the nonlinearity is
cubic, whereas an approximate model for describing the behaviour of strongly -
interacting (low density) gases is one characterized by a quintic nonlinearity.
We use an approximate analytical expression for the form of the nonlinearity in
the intermediate regimes to show that, near the crossover between the two
different regimes, the soliton is predicted and numerically confirmed to
oscillate at a frequency of $\sqrt{2/3}\Omega$, where $\Omega$ is the harmonic
trap frequency.
\\ ( , 80kb)
Paper: cond-mat/0701051
Date: Wed, 3 Jan 2007 15:32:23 GMT (410kb)

Title: Collisional properties of sympathetically cooled $^{39}$K
Authors: L. De Sarlo, P. Maioli, G. Barontini, J. Catani, F. Minardi, and M.
Categories: cond-mat.other
Comments: 7 pages, 4 figures, submitted to Phys. Rev. A
Subj-class: Other
   We report the experimental evidence of the sympathetic cooling of $^{39}$K
with $^{87}$Rb down to 1 $\mu$K, obtained in a novel tight confining magnetic
trap. This allowed us to perform the first direct measurement of the elastic
cross section of $^{39}$K below 50 $\mu$K. The result obtained for the triplet
scattering length, $a_T = -51(7)$ Bohr radii, agrees with previous results
derived from photoassociation spectra and from Feshbach spectroscopy of
\\ ( , 410kb)
Paper: cond-mat/0701057
Date: Wed, 3 Jan 2007 20:12:33 GMT (24kb)

Title: Using time reversal symmetry for sensitive incoherent matter-wave Sagnac
Authors: Y. Japha, O. Arzouan, Y. Avishai and R. Folman
Categories: cond-mat.other
Subj-class: Other
   We present a theory of the transmission of incoherent guided matter-waves
through Sagnac interferometers. Interferometer configurations with only one
input and one output port have a property similar to the phase rigidity
observed in the transmission through Aharonov-Bohm interferometers in coherent
mesoscopic electronics. This property is connected to the existence of
counterpropagating paths of equal length and enables the operation of such
matter-wave interferometers with incoherent sources. High finesse
interferometers of this kind have a rotation sensitivity inversely proportional
to the square root of the finesse.
\\ ( , 24kb)
Paper: cond-mat/0701058
Date: Wed, 3 Jan 2007 21:00:24 GMT (9kb)

Title: Decoherence dynamics in low-dimensional cold atoms interferometers
Authors: A.A. Burkov, M.D. Lukin, Eugene Demler
Categories: cond-mat.supr-con cond-mat.str-el
Comments: 4 pages
Subj-class: Superconductivity; Strongly Correlated Electrons
   We report on a study of the dynamics of decoherence of a matter-wave
interferometer, consisting of a pair of low-dimensional cold atoms condensates
at finite temperature. We identify two distinct regimes in the time dependence
of the coherence factor of the interferometer: quantum and classical. Explicit
analytical results are obtained in both regimes. In particular, in the
two-dimensional (2D) case in the classical (long time) regime, we find that the
dynamics of decoherence is universal, exhibiting a power-law decay with an
exponent, proportional to the ratio of the temperature to the
Kosterlitz-Thouless temperature of a single 2D condensate. In the
one-dimensional (1D) case in the classical regime we find a universal
nonanalytic time dependence of decoherence, which is a consequence of the
nonhydrodynamic nature of damping in 1D liquids.
\\ ( , 9kb)


Paper: cond-mat/0612616
replaced with revised version Fri, 29 Dec 2006 12:23:15 GMT (65kb)

Title: Role of excited states in the splitting dynamics of interacting
   Bose-Einstein condensates when ramping-up a barrier
Authors: Alexej I. Streltsov, Ofir E. Alon and Lorenz S. Cederbaum
Categories: cond-mat.other
Comments: 11 pages, 3 figures
Subj-class: Other
\\ ( , 65kb)
Paper: cond-mat/0604063
replaced with revised version Sat, 30 Dec 2006 10:48:58 GMT (348kb)

Title: Disorder versus the Mermin-Wagner-Hohenberg effect: From classical spin
   systems to ultracold atomic gases
Authors: Jan Wehr (ICFO, University of Arizona), Armand Niederberger (ICFO),
   Laurent Sanchez-Palencia (LCFIO), Maciej Lewenstein (ICFO)
Categories: cond-mat.other
Comments: published version; 8 pages, 3 figures
Proxy: ccsd ccsd-00022177
Subj-class: Other
Journal-ref: Physical Review B 74 (2006) 224448
DOI: 10.1103/PhysRevB.74.224448
\\ ( , 348kb)
Paper: cond-mat/0606201
replaced with revised version Tue, 2 Jan 2007 04:33:13 GMT (95kb)

Title: Quantum limits to center-of-mass measurements
Authors: Timothy Vaughan, Peter Drummond, Gerd Leuchs
Categories: cond-mat.other cond-mat.mes-hall
Comments: 12 pages, 6 figures. Submitted to PRA. Revised to include more
   references as well as a discussion of fermionic center-of-mass
Subj-class: Other; Mesoscopic Systems and Quantum Hall Effect
\\ ( , 95kb)
Paper: cond-mat/0609307
replaced with revised version Mon, 1 Jan 2007 08:38:51 GMT (241kb)

Title: Hidden order in 1D Bose insulators
Authors: Emanuele G. Dalla Torre, Erez Berg, Ehud Altman
Categories: cond-mat.other cond-mat.str-el
Comments: Letter
Subj-class: Other; Strongly Correlated Electrons
\\ ( , 241kb)
Paper: cond-mat/0610071
replaced with revised version Tue, 2 Jan 2007 18:56:30 GMT (359kb)

Title: Ground states of spin-3 Bose-Einstein condensates for conserved
Authors: Harri M\"akel\"a, Kalle-Antti Suominen
Categories: cond-mat.other
Comments: 8 pages, 4 figures; text and references added, one new figure
Subj-class: Other
\\ ( , 359kb)
Paper: cond-mat/0612376
replaced with revised version Tue, 2 Jan 2007 23:27:16 GMT (59kb)

Title: Expansion of a mesoscopic Fermi system from a harmonic trap
Authors: Pavel Nagornykh and Victor Galitski
Categories: cond-mat.mes-hall cond-mat.supr-con
Comments: 4 pages, 1 color figure; v2.: A reference added
Subj-class: Mesoscopic Systems and Quantum Hall Effect; Superconductivity
\\ ( , 59kb)
Paper: cond-mat/0605154
replaced with revised version Wed, 3 Jan 2007 23:44:53 GMT (19kb)

Title: Emergence of Artificial Photons in an Optical Lattice
Authors: Sumanta Tewari, V. W. Scarola, T. Senthil, S. Das Sarma
Categories: cond-mat.str-el
Comments: 4 pages, 2 eps figure
Subj-class: Strongly Correlated Electrons
Journal-ref: Phys. Rev. Lett. 97, 200401 (2006)
DOI: 10.1103/PhysRevLett.97.200401
\\ ( , 19kb)
Paper: physics/0610210
replaced with revised version Wed, 3 Jan 2007 17:01:34 GMT (20kb)

Title: Feshbach resonances in ultracold atomic and molecular collisions:
   threshold behavior and suppression of poles in scattering lengths
Authors: Jeremy M. Hutson
Categories: physics.atom-ph physics.chem-ph
Comments: 4 pages, 1 figure. Version 3 revised to emphasise the importance of
   the_relative_ strength of elastic and inelastic couplings and to explain when
   strong suppression of resonant peaks is (or is not) expected
Subj-class: Atomic Physics; Chemical Physics
\\ ( , 20kb)

Till next time (it won't be as long)

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
Matt's arXiv selection: weekly summary of cold-atom papers from
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Received on Thu Jan 11 2007 - 14:38:06 EST

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