# Matt's arXiv selection: week ending 30 May 2008.

From: Matthew Davis <mdavis_at_physics.uq.edu.au>
Date: Thu, 19 Jun 2008 22:40:30 +1000

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

Still lagging behind... this week there were 26 new preprints and 8 replacements.

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arXiv:0805.3519
Date: Thu, 22 May 2008 18:03:04 GMT (411kb)

Title: Observation of a 2D Bose-gas: from thermal to quasi-condensate to
superfluid
Authors: P. Clad\'e, C. Ryu, A. Ramanathan, K. Helmerson and W. D. Phillips
Categories: cond-mat.other
\\
We present experimental results on a Bose gas in a quasi-2D geometry near the
Berezinskii, Kosterlitz and Thouless (BKT) transition temperature. By measuring
the density profile, \textit{in situ} and after time of flight, and the
coherence length, we identify different states of the gas. In particular, we
observe that the gas develops a bimodal distribution without long range order.
In this state, the gas presents a longer coherence length than the thermal
cloud; it is quasi-condensed but is not superfluid. Experimental evidence
indicates that we observe the superfluid transition (BKT transition).
\\ ( http://arxiv.org/abs/0805.3519 , 411kb)
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arXiv:0805.3663
Date: Fri, 23 May 2008 19:57:53 GMT (481kb)

Title: Phase diagram, extended domain walls, and soft collective modes in a
three component fermionic superfluid
Authors: G. Catelani, E. A. Yuzbashyan
Categories: cond-mat.other cond-mat.supr-con
\\
We study the phase diagram of a three component Fermi gas with weak
attractive interactions, which shows three superfluid and one normal phases. At
weak symmetry breaking between the components the existence of domain walls
interpolating between two superfluids introduces a new length scale much larger
than the coherence length of each superfluid. This, in particular, limits the
applicability of the local density approximation in the trapped case, which we
also discuss. In the same regime the system hosts soft collective modes with a
mass much smaller than the energy gaps of individual superfluids. We derive
their dispersion relations at zero and finite temperatures and demonstrate that
their presence leads to a significant enhancement of fluctuations near the
superfluid-normal transitions.
\\ ( http://arxiv.org/abs/0805.3663 , 481kb)
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arXiv:0805.3667
Date: Fri, 23 May 2008 17:17:37 GMT (30kb)

Title: Spin polarons and molecules in strongly-interacting atomic Fermi gases
Authors: P. Massignan, G. M. Bruun, H. T. C. Stoof
Categories: cond-mat.other
\\
We examine pairing and molecule formation in strongly-interacting Fermi
gases, and we discuss how radio-frequency (RF) spectroscopy can reveal these
features. For the balanced case, the emergence of stable molecules in the BEC
regime results in a two-peak structure in the RF spectrum with clearly visible
medium effects on the low-energy part of the molecular wavefunction. For the
highly-imbalanced case, we show the existence of a well-defined quasiparticle
(a spin polaron) on both sides of the Feshbach resonance, we evaluate its
lifetime, and we illustrate how its energy may be measured by RF spectroscopy.
\\ ( http://arxiv.org/abs/0805.3667 , 30kb)
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arXiv:0805.3680
Date: Fri, 23 May 2008 18:32:18 GMT (754kb)

Title: Quantum behavior of the dc SQUID phase qubit
Authors: Kaushik Mitra, F. W. Strauch, C. J. Lobb, J. R. Anderson, F. C.
Wellstood, and Eite Tiesinga
Categories: cond-mat.supr-con cond-mat.other
\\
We analyze the behavior of a dc Superconducting Quantum Interference Device
(SQUID) phase qubit in which one junction acts as a phase qubit and the rest of
the device provides isolation from dissipation and noise in the bias leads.
Ignoring dissipation, we find the two-dimensional Hamiltonian of the system and
use numerical methods and a cubic approximation to solve Schrodinger's equation
for the eigenstates, energy levels, tunneling rates, and expectation value of
the currents in the junctions. Using these results, we investigate how well
this design provides isolation while preserving the characteristics of a phase
qubit. In addition, we show that the expectation value of current flowing
through the isolation junction depends on the state of the qubit and can be
used for non-destructive read out of the qubit state.
\\ ( http://arxiv.org/abs/0805.3680 , 754kb)
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arXiv:0805.3693
Date: Sun, 25 May 2008 01:47:34 GMT (204kb)

Title: Itinerant Ferromagnetism in an Atom Trap
Authors: Ilya Berdnikov, P. Coleman, Steven H. Simon
Categories: cond-mat.str-el
\\
We propose an experiment to explore the magnetic phase transitions in
interacting fermionic Hubbard systems, and establish signatures of
ferromagnetic correlations in the observed ground states. We find that for
large trap radii (trap radius $R_T > 4$, in units of coherence length $\xi$),
ground states are topological in nature -- a skyrmion'' in 2D, and a
hedgehog'' in 3D. Finally, we describe how to obtain the ferromagnetic phase
diagram of itinerant electron systems from these experiments.
\\ ( http://arxiv.org/abs/0805.3693 , 204kb)
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arXiv:0805.3713
Date: Fri, 23 May 2008 20:36:46 GMT (17kb)

Title: Local stress and superfluid properties of solid Helium-4
Authors: L. Pollet, M. Boninsegni, A. B. Kuklov, N.V. Prokofev, B.V. Svistunov,
M. Troyer
Categories: cond-mat.stat-mech
\\
More than half a century ago Penrose asked: are the superfluid and solid
state of matter mutually exclusive or do there exist "supersolid" materials
where the atoms form a regular lattice and simultaneously flow without
friction? Recent experiments provide evidence that supersolid behavior indeed
exists in Helium-4 -- the most quantum material known in Nature. In this paper
we show that large local strain in the vicinity of crystalline defects is the
origin of supersolidity in Helium-4. Although ideal crystals of Helium-4 are
not supersolid, the gap for vacancy creation closes when applying a moderate
stress. While a homogeneous system simply becomes unstable at this point, the
stressed core of crystalline defects (dislocations and grain boundaries)
undergoes a radical transformation and can become superfluid.
\\ ( http://arxiv.org/abs/0805.3713 , 17kb)
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arXiv:0805.3730
Date: Fri, 23 May 2008 23:31:58 GMT (132kb)

Title: Nonlinear Dynamic Phenomena in Macroscopic Tunneling
Authors: G. Dekel, O.V. Farberovich, A. Soffer, V. Fleurov
Categories: cond-mat.other
\\
Numerical simulations of the NLSE (or GPE) are presented demonstrating
emission of short pulses of the matter (light) density formed in the course of
tunneling in wave-guided light and/or trapped BEC. The phenomenon is observed
under various conditions, for nonlinearities of different signs, zero
nonlinearity included. We study, both numerically and analytically, pulsations
of matter (light) remaining within the trap and use the results in order to
induce emission of sequential pulses by properly narrowing the trap. This
allows us to propose a mechanism for a realization of Atom Pulse Laser.
\\ ( http://arxiv.org/abs/0805.3730 , 132kb)
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arXiv:0805.3734
Date: Sat, 24 May 2008 01:00:22 GMT (681kb)

Title: Stochastic time-dependent current-density functional theory: a
functional theory of open quantum systems
Authors: R. D'Agosta and M. Di Ventra
Categories: cond-mat.str-el cond-mat.mes-hall
Comments: 16 pages, 7 figures, RevTex4
\\
The dynamics of a many-body system coupled to an external environment
represents a fundamentally important problem. To this class of open quantum
systems pertains the study of energy transport and dissipation, dephasing,
quantum measurement and quantum information theory, phase transitions driven by
dissipative effects, etc. Here, we discuss in detail an extension of
time-dependent current-density-functional theory (TDCDFT), we named stochastic
TDCDFT [Phys. Rev. Lett. {\bf 98}, 226403 (2007)], that allows the description
of such problems from a microscopic point of view. We discuss the assumptions
of the theory, its relation to a density matrix formalism, and the limitations
of the latter in the present context. In addition, we describe a numerically
convenient way to solve the corresponding equations of motion, and apply this
theory to the dynamics of a 1D gas of excited bosons confined in a harmonic
potential and in contact with an external bath.
\\ ( http://arxiv.org/abs/0805.3734 , 681kb)
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arXiv:0805.3786
Date: Sun, 25 May 2008 09:52:09 GMT (101kb)

Title: Fermionization and bosonization of expanding 1D anyonic fluids
Authors: A. del Campo
Categories: cond-mat.stat-mech
\\
The momentum distribution of an expanding cloud of one-dimensional hard-core
anyons is studied by an exact numerical approach, and shown to become
indistinguishable from that of a non-interacting spin-polarized Fermi gas for
large enough times (dynamical fermionization). We also consider the expansion
of one-dimensional anyons with strongly attractive short-range interactions
suddenly released from a parabolic external potential, and find that momentum
distribution approaches that of its dual system, the ideal Bose gas (dynamical
bosonization). For both processes the characteristic time scales are
identified, and the effect of the initial confinement is analyzed comparing the
dynamics associated with both harmonic and hard-wall traps.
\\ ( http://arxiv.org/abs/0805.3786 , 101kb)
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arXiv:0805.3870
Date: Mon, 26 May 2008 03:59:40 GMT (379kb)

Title: Stability of the density-wave state of a dipolar condensate in a pancake
trap
Authors: O. Dutta, R. Kanamoto, P. Meystre
Categories: cond-mat.other
\\
We study a dipolar boson-fermion mixture in a pancake geometry at absolute
zero temperature, generalizing our previous work on the stability of polar
condensates and the formation of a density-wave state in cylindrical traps.
After examining the dependence of the polar condensate stability on the
strength of the fermion-induced interaction, we determine the transition point
from a ground-state Gaussian to a hexagonal density-wave state. We use a
variational principle to analyze the stability properties of those density-wave
state.
\\ ( http://arxiv.org/abs/0805.3870 , 379kb)
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arXiv:0805.3889
Date: Mon, 26 May 2008 16:43:33 GMT (57kb)

Title: Effect of disorder on the interacting Fermi gases in a one-dimensional
optical lattice
Authors: Gao Xianlong, M. Polini, M. P. Tosi, and B. Tanatar
Categories: cond-mat.dis-nn cond-mat.str-el
Comments: 11 pages, 6 figures, submitted
\\
Interacting two-component Fermi gases loaded in a one-dimensional (1D)
lattice and subjected to an harmonic trapping potential exhibit interesting
compound phases in which fluid regions coexist with local Mott-insulator and/or
band-insulator regions. Motivated by experiments on cold atoms inside
disordered optical lattices, we present a theoretical study of the effects of a
correlated random potential on these ground-state phases. We employ a lattice
version of density-functional theory within the local-density approximation to
determine the density distribution of fermions in these phases. The
exchange-correlation potential is obtained from the Lieb-Wu exact solution of
Fermi-Hubbard model. On-site disorder (with and without Gaussian correlations)
and harmonic trap are treated as external potentials. We find that disorder has
two main effects: (i) it destroys the local insulating regions if it is
sufficiently strong compared with the on-site atom-atom repulsion, and (ii) it
induces an anomaly in the inverse compressibility at low density from quenching
of percolation. For sufficiently large disorder correlation length the
enhancement in the inverse compressibility diminishes.
\\ ( http://arxiv.org/abs/0805.3889 , 57kb)
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arXiv:0805.3735
Date: Sat, 24 May 2008 01:08:16 GMT (163kb)

Title: Coupling nanomechanical cantilevers to dipolar molecules
Authors: S. Singh, M. Bhattacharya, O. Dutta and P. Meystre
Categories: quant-ph
\\
We investigate the coupling of a nanomechanical oscillator in the quantum
regime with molecular (electric) dipoles. We find theoretically that the
cantilever can produce single-mode squeezing of the center-of-mass motion of an
isolated trapped molecule and two-mode squeezing of the phonons of an array of
molecules. This work opens up the possibility of manipulating dipolar crystals,
which have been recently proposed as quantum memory, and more generally, is
indicative of the promise of nanoscale cantilevers for the quantum detection
and control of atomic and molecular systems.
\\ ( http://arxiv.org/abs/0805.3735 , 163kb)
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arXiv:0805.3797
Date: Sat, 24 May 2008 23:09:20 GMT (500kb,D)

Title: Faraday spectroscopy of atoms confined in a dark optical trap
Authors: Matthew L. Terraciano, Mark Bashkansky, Fredrik Fatemi
Categories: quant-ph
Comments: 6 pages, 8 figures Accepted in Phys. Rev. A
\\
We demonstrate Faraday spectroscopy with high duty cycle and sampling rate
using atoms confined to a blue-detuned optical trap. Our trap consists of a
crossed pair of high-charge-number hollow laser beams, which forms a dark,
box-like potential. We have used this to measure transient magnetic fields in a
500-micron-diameter spot over a 400 ms time window with nearly unit duty cycle
at a 500 Hz sampling rate. We use these measurements to quantify and compensate
time-varying magnetic fields to ~10 nT per time sample.
\\ ( http://arxiv.org/abs/0805.3797 , 500kb)
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arXiv:0805.3801
Date: Sat, 24 May 2008 23:46:47 GMT (42kb)

Title: Photo-detection using Bose-condensed atoms in a micro trap
Authors: S. Wallentowitz, A. B. Klimov
Categories: quant-ph
\\
A model of photo-detection using a Bose--Einstein condensate in an atom-chip
based micro trap is analyzed. Atoms absorb photons from the incident light
field, receive part of the photon momentum and leave the trap potential. Upon
counting of escaped atoms within predetermined time intervals, the photon
statistics of the incident light is mapped onto the atom-count statistics.
Whereas traditional photo-detection theory treats the emission centers of photo
electrons as distinguishable, here the centers of escaping atoms are condensed
and thus indistinguishable atoms. From this a deviation of the commonly known
counting formula is derived.
\\ ( http://arxiv.org/abs/0805.3801 , 42kb)
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arXiv:0805.3854
Date: Mon, 26 May 2008 00:54:53 GMT (206kb)

Title: Single Atom Detection With Optical Cavities
Authors: R. Poldy, B. C. Buchler, J. C. Close
Categories: quant-ph
Comments: 11 pages, 8 figures, submitted to PRA
\\
We present a thorough analysis of single atom detection using optical
cavities. The large set of parameters that influence the signal-to-noise ratio
for cavity detection is considered, with an emphasis on detunings, probe power,
cavity finesse and photon detection schemes. Real device operating restrictions
for single photon counting modules and standard photodiodes are included in our
discussion, with heterodyne detection emerging as the clearly favourable
technique, particularly for detuned detection at high power.
\\ ( http://arxiv.org/abs/0805.3854 , 206kb)
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arXiv:0805.4002
Date: Mon, 26 May 2008 18:23:05 GMT (198kb)

Title: A Wave Function approach to dissipative processes
Authors: Yvan Castin, Jean Dalibard and Klaus Molmer
Categories: quant-ph
\\
Due to growing interest in quantum measurement, control and feedback, we
reproduce a manuscript from 1992, presenting a simple physical and mathematical
derivation of stochastic differential equations for wave functions of probed
quantum systems. V. P. Belavkins seminal quantum filtering theory with similar
equations, developed in the 1980es, was not known to the authors at the time of
writing of the present manuscript.
\\ ( http://arxiv.org/abs/0805.4002 , 198kb)
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arXiv:0805.3708
Date: Fri, 23 May 2008 20:26:38 GMT (164kb,D)

Title: Light Assisted Collisional Loss in a $^{85/87}$Rb Ultracold Optical Trap
Authors: Anthony R. Gorges, Nicholas S. Bingham, Michael K. DeAngelo, Mathew S.
Hamilton, and Jacob L. Roberts
Categories: physics.atom-ph
\\
We have studied hetero- and homonuclear excited state/ground state collisions
by loading both $^{85}$Rb and $^{87}$Rb into a far off resonant trap (FORT).
Because of the relatively weak confinement of the FORT, we expect the hyperfine
structure of the different isotopes to play a crucial role in the collision
rates. This dependence on hyperfine structure allows us to measure collisions
associated with long range interatomic potentials of different structure: such
as long and short ranged; or such as purely attractive, purely repulsive, or
mixed attractive and repulsive. We observe significantly different loss rates
for different excited state potentials. Additionally, we observe that some
collisional channels' loss rates are saturated at our operating intensities
(~15 mW/cm$^{2}$). These losses are important limitations in loading dual
isotope optical traps.
\\ ( http://arxiv.org/abs/0805.3708 , 164kb)
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arXiv:0805.4028
Date: Tue, 27 May 2008 00:59:05 GMT (362kb)

Title: 1D-FFLO state in the absence of time-reversal symmetry breaking
Authors: Trinanjan Datta
Categories: cond-mat.str-el cond-mat.supr-con
\\
A novel route to a one-dimensional Fulde-Ferrell-Larkin-Ovchinnikov (1D-FFLO)
state in the absence of broken time-reversal symmetry is proposed in this
paper. At present such a state may be encouraged in a clean AlAs quantum wire.
Using the AlAs quantum wire as an example it is shown using bosonization and
the renormalization group approach that the 1D-FFLO state can arise due to a
combination of Coulomb interactions and the unique bandstructure arrangement of
the AlAs quantum wire. The present theoretical proposal is very general and is
applicable to other systems with similar fermionic interaction terms.
\\ ( http://arxiv.org/abs/0805.4028 , 362kb)
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arXiv:0805.4036
Date: Tue, 27 May 2008 02:19:32 GMT (37kb)

Title: Diagrammatic calculation of energy spectrum of quantum impurity in
degenerate Bose-Einstein condensate
Authors: Alexey Novikov, Mikhail Ovchinnikov
Categories: quant-ph
\\
In this paper we considered a quantum particle moving through delute
Bose-Einstein condensate at zero temperature. In our formulation the impurity
particle interacts with the gas of uncoupled Bogoliubov's excitations. We
constructed the perturbation theory for the Green's function of the impurity
particle with respect to the impurity-condensate interaction employing the
coherent-state path integral approach. The perturbative expansion for the
Green's function is resumed into the expansion for its poles with the help of
the diagrammatic technique developed in this work. The dispersion relation for
the impurity clothed by condensate excitations is obtained and effective mass
is evaluated beyond the Golden rule approximation.
\\ ( http://arxiv.org/abs/0805.4036 , 37kb)
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arXiv:0805.4198
Date: Tue, 27 May 2008 20:01:04 GMT (40kb)

Title: Realizing the strongly correlated $d$-Mott state in a fermionic cold
atom optical lattice
Authors: Michael R. Peterson, Chuanwei Zhang, Sumanta Tewari, S. Das Sarma
Categories: cond-mat.str-el
\\
We show that a new state of matter, the $d$-Mott state, characterized by a
non-zero expectation value of a local plaquette operator embedded in an
insulating state, can be engineered using ultra-cold atomic fermions in
two-dimensional double-well optical lattices. We characterize and analyze the
parameter regime where the $d$-Mott state is stable. We predict the testable
signatures of the state in the time-of-flight measurements.
\\ ( http://arxiv.org/abs/0805.4198 , 40kb)
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arXiv:0805.4203
Date: Tue, 27 May 2008 20:13:51 GMT (128kb)

Title: $p_{x}+ip_{y}$ superfluid from s-wave interactions of fermionic cold
atoms
Authors: Chuanwei Zhang, Sumanta Tewari, Roman Lutchyn, and S. Das Sarma
Categories: cond-mat.mes-hall cond-mat.str-el
\\
Two-dimensional ($p_{x}+ip_{y}$) superfluids/superconductors offer a
playground for studying intriguing physics such as quantum teleportation,
non-Abelian statistics, and topological quantum computation. Creating such a
superfluid in cold fermionic atom optical traps using p-wave Feshbach resonance
is turning out to be challenging. Here we propose a method to create a
$p_{x}+ip_{y}$ superfluid directly from an s-wave interaction making use of a
topological Berry phase, which can be artificially generated. We discuss ways
to detect the spontaneous Hall mass current, which acts as a diagnostic for the
chiral p-wave superfluid.
\\ ( http://arxiv.org/abs/0805.4203 , 128kb)
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arXiv:0805.4261
Date: Wed, 28 May 2008 05:34:22 GMT (997kb)

Title: Mott Phase in Polarized Two-component Atomic Fermi Lattice Gas:A
Playground for S=1/2 Heisenberg Model in Magnetic Field
Authors: M. Machida, M. Okumura, S. Yamada, T. Deguchi, Y. Ohashi, H. Matsumoto
Categories: cond-mat.str-el
\\
We investigate effects of pseudo-spin population imbalance on Mott phases in
1D trapped two-component atomic Fermi gases loaded on optical lattices based on
the repulsive Hubbard model in harmonic traps. By using the density matrix
renormalization group method, we numerically calculate density profiles of each
component and clarify the pseudo-spin magnetism. In the case of large
population imbalance, we find Wigner crystal like structures for the spatial
distribution of the minority pseudo-spin component inside the central Mott
core. When the population imbalance becomes small, the structure disappears,
and antiferromagnetic configurations instead appear together with their
spin-density wave like modulations. These all features are well described by
S=1/2 antiferromagnetic Heisenberg chain under magnetic field.
\\ ( http://arxiv.org/abs/0805.4261 , 997kb)
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arXiv:0805.4295
Date: Wed, 28 May 2008 11:28:23 GMT (341kb)

Title: Fast Sweeping into Feshbach Molecules as a Probe of Fermionic
Condensates
Authors: S. Matyjaskiewicz, M. H. Szymanska, K. Goral
Categories: cond-mat.other
\\
Fast sweep projection onto Feshbach molecules has been widely used as a probe
to explore the properties of fermionic condensates, in particular the
condensate fraction. By determining the exact dynamics of a pair of atoms in
time varying magnetic fields across a Feshbach resonance, we calculate the
number of condensed and noncondensed molecules created after fast magnetic
field sweeps from the BCS to the BEC side of the resonance. We analyse the
dependence of the molecular conversion efficiency for condensed and
noncondensed molecules on the sweep rate, and on the initial and final magnetic
fields, for $^{40}$K and $^{6}$Li resonances; and discuss the relation between
the initial fermionic condensate fraction and the molecular condensate fraction
measured after the sweep.
\\ ( http://arxiv.org/abs/0805.4295 , 341kb)
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arXiv:0805.4327
Date: Wed, 28 May 2008 12:07:03 GMT (776kb)

Title: Electromagnetically induced transparency of an interacting cold Rydberg
ensemble
Authors: K. J. Weatherill, J. D. Pritchard, R. P. Abel, M. G. Bason, A. K.
Categories: quant-ph
\\
We study electromagnetically induced transparency (EIT) of a weakly
interacting cold Rydberg gas. We show that the onset of interactions is
manifest as a depopulation of the Rydberg state and numerically model this
effect by adding a density-dependent non-linear term to the optical Bloch
equations. In the limit of a weak probe where the depopulation effect is
negligible, we observe no evidence of interaction induced decoherence and
obtain a narrow Rydberg dark resonance with a linewidth of <600 kHz, limited by
the Rabi frequency of the coupling beam
\\ ( http://arxiv.org/abs/0805.4327 , 776kb)
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arXiv:0805.4484
Date: Thu, 29 May 2008 08:49:17 GMT (165kb,D)

Title: The p-band in a rotating optical lattice
Authors: R.O. Umucalilar, M.O. Oktel
Categories: cond-mat.other
\\
We investigate the effects of rotation on the excited bands of a tight
binding lattice, focusing particulary on the first excited (p-) band. Both the
on-site energies and the hopping between lattice sites are modified by the
effective magnetic field created by rotation, causing a non-trivial splitting
and magnetic fine structure of the p-band. We show that Peierls substitution
can be modified to describe p-band under rotation, and use this method to
derive an effective Hamiltonian. We compare the spectrum of the effective
Hamiltonian with a first principles calculation of the magnetic band structure
and find excellent agreement, confirming the validity of our approach. We also
discuss the on-site interaction terms for bosons and argue that many-particle
phenomena in a rotating p-band can be investigated starting from this effective
Hamiltonian.
\\ ( http://arxiv.org/abs/0805.4484 , 165kb)
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arXiv:0805.4447
Date: Wed, 28 May 2008 22:47:05 GMT (3kb)

Title: Stability of Double-Ring Bose-Einstein Condensates
Authors: Joachim Brand, Tania J. Haigh, and Ulrich Z\"ulicke
Categories: quant-ph
Comments: 1 page, comment on Phys. Rev. Lett. 98, 050401 (2007)
[arXiv:quant-ph/0609133v2]
\\
We revisit recent claims about the instability of non-rotating coupled
annular Bose-Einstein condensates (BECs) leading to the emergence of
angular-momentum Josephson oscillation. In their Letter [Phys. Rev. Lett. 98,
050401 (2007), arXiv:quant-ph/0609133v2], Lesanovsky and von Klitzing predict
all stationary states with uniform density to be unstable. This prediction
turns out to be based on faulty calculations leading to incorrect conclusions.
We show that there is a stable non-rotating and uniform ground state for any
value of the tunnel coupling and repulsive interactions. The instability of an
excited state with $\pi$ phase difference between the condensates can be
interpreted in terms of the familiar snake instability.
\\ ( http://arxiv.org/abs/0805.4447 , 3kb)
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The replacements:

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arXiv:0801.2910
replaced with revised version Mon, 26 May 2008 13:35:41 GMT (477kb)

Title: Functional renormalization for Bose-Einstein Condensation
Authors: S. Floerchinger and C. Wetterich
Categories: cond-mat.supr-con cond-mat.str-el hep-th
Journal-ref: Phys. Rev. A 77, 053603 (2008)
DOI: 10.1103/PhysRevA.77.053603
\\ ( http://arxiv.org/abs/0801.2910 , 477kb)
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arXiv:0802.0333
replaced with revised version Mon, 26 May 2008 03:47:30 GMT (205kb)

Title: Magneto-Optical Stern-Gerlach Effect in Atomic Ensemble
Authors: Yu Guo, Lan Zhou, Le-Man Kuang, C.P. Sun
Categories: quant-ph
\\ ( http://arxiv.org/abs/0802.0333 , 205kb)
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arXiv:0802.1585
replaced with revised version Sat, 24 May 2008 02:00:48 GMT (897kb)

Title: Experimental Realization of an Optical One-Way Barrier for Neutral Atoms
Authors: Jeremy J. Thorn, Elizabeth A. Schoene, Tao Li, and Daniel A. Steck
Categories: physics.atom-ph
\\ ( http://arxiv.org/abs/0802.1585 , 897kb)
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arXiv:0801.2056
replaced with revised version Tue, 27 May 2008 09:12:52 GMT (206kb)

Title: Double and negative reflection of cold atoms in non-Abelian gauge
potentials
Authors: Gediminas Juzeliunas, Julius Ruseckas, Andreas Jacob, Luis Santos,
Patrik Ohberg
Categories: cond-mat.other physics.atom-ph quant-ph
Journal-ref: Phys. Rev. Lett. 100, 200405 (2008)
DOI: 10.1103/PhysRevLett.100.200405
\\ ( http://arxiv.org/abs/0801.2056 , 206kb)
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arXiv:0804.0109
replaced with revised version Tue, 27 May 2008 12:41:23 GMT (213kb)

Title: Mechanisms for Lasing with Cold Atoms as the Gain Medium
Authors: William Guerin (INLN), Franck Michaud (INLN), Robin Kaiser (INLN)
Categories: physics.atom-ph cond-mat.dis-nn physics.optics
\\ ( http://arxiv.org/abs/0804.0109 , 213kb)
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arXiv:cond-mat/0702462
replaced with revised version Thu, 29 May 2008 12:20:34 GMT (49kb)

Title: Efimov states near a Feshbach resonance
Authors: P. Massignan and H. T. C. Stoof
Categories: cond-mat.other
Comments: 4 pages, 5 figures; revised discussion after Eq. (2) on the insertion
of a correction to the inverse two-body T-matrix
\\ ( http://arxiv.org/abs/cond-mat/0702462 , 49kb)
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arXiv:0708.1898
replaced with revised version Thu, 29 May 2008 10:47:41 GMT (329kb)

Title: On the dynamics of point vortices in a quantum gas confined in an
annular region
Authors: Markus Lakaniemi
Categories: cond-mat.stat-mech quant-ph
Comments: 14 pages, 4 figures. A new version of the original paper
\\ ( http://arxiv.org/abs/0708.1898 , 329kb)
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arXiv:0803.0183
replaced with revised version Thu, 29 May 2008 16:30:26 GMT (316kb)

Title: Optimal control of atom transport for quantum gates in optical lattices
Authors: G. De Chiara, T. Calarco, M. Anderlini, S. Montangero, P. J. Lee, B.
L. Brown, W. D. Phillips, and J. V. Porto
Categories: quant-ph cond-mat.other
Journal-ref: Phys. Rev. A 77, 052333 (2008)
DOI: 10.1103/PhysRevA.77.052333
\\ ( http://arxiv.org/abs/0803.0183 , 316kb)
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Till next time,
Matt.

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Received on Fri Jul 04 2008 - 08:30:27 EST

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