# Matt's arXiv selection: week ending 13 June 2008

From: Matthew Davis <mdavis_at_physics.uq.edu.au>
Date: Fri, 27 Jun 2008 09:40:52 +1000

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

Now only two weeks behind... this week there were 28 new preprints and 12
replacements.

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arXiv:0806.1114
Date: Fri, 6 Jun 2008 09:33:18 GMT (51kb)

Title: Finite size Berezinski-Kosterlitz-Thouless transition at grain
boundaries in solid $^4$He and role of $^3$He impurities
Authors: S. Gaudio, E. Cappelluti, G. Rastelli, L. Pietronero
Categories: cond-mat.other
\\
We analyze the complex phenomenology of the Non-Classical Rotational Inertia
(NCRI) observed at low temperature in solid $^4$He within the context of a two
dimensional Berezinski-Kosterlitz-Thouless transition in a premelted $^4$He
film at the grain boundaries. We show that both the temperature and $^3$He
doping dependence of the NCRI fraction (NCRIF) can be ascribed to finite size
effects induced by the finite grain size. We give an estimate of the average
size of the grains which we argue to be limited by the isotopic $^3$He
impurities and we provide a simple power-law relation between the NCRIF and the
$^3$He concentration.
\\ ( http://arxiv.org/abs/0806.1114 , 51kb)
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arXiv:0806.1181
Date: Fri, 6 Jun 2008 15:00:36 GMT (24kb)

Title: Some remarks on the coherent-state variational approach to nonlinear
boson models
Authors: P. Buonsante and V. Penna (Politecnico di Torino)
Categories: cond-mat.other cond-mat.stat-mech
Journal-ref: J. Phys. A: Math. Theor., 41 (2008) 175301
DOI: 10.1088/1751-8113/41/17/175301
\\
The mean-field pictures based on the standard time-dependent variational
approach have widely been used in the study of nonlinear many-boson systems
such as the Bose-Hubbard model. The mean-field schemes relevant to
Gutzwiller-like trial states $|F>$, number-preserving states $|\xi >$ and
Glauber-like trial states $|Z>$ are compared to evidence the specific
properties of such schemes. After deriving the Hamiltonian picture relevant to
$|Z>$ from that based on $|F>$, the latter is shown to exhibit a Poisson
algebra equipped with a Weyl-Heisenberg subalgebra which preludes to the
$|Z>$-based picture. Then states $|Z>$ are shown to be a superposition of $\cal N$-boson states $|\xi>$ and the similarities/differences of the $|Z>$-based and
$|\xi>$-based pictures are discussed. Finally, after proving that the simple,
symmetric state $|\xi>$ indeed corresponds to a SU(M) coherent state, a dual
version of states $|Z>$ and $|\xi>$ in terms of momentum-mode operators is
discussed together with some applications.
\\ ( http://arxiv.org/abs/0806.1181 , 24kb)
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arXiv:0806.1201
Date: Fri, 6 Jun 2008 16:23:47 GMT (19kb)

Title: Stability of persistent currents in a Bose-Einstein condensate confined
in a toroidal trap
Authors: M. Ogren, G. M. Kavoulakis
Categories: cond-mat.other
\\
Motivated by recent experiments in Bose-Einstein condensed atoms that have
been confined in toroidal traps, we examine the stability of persistent
currents in such systems. We investigate the extent that the stability of these
currents may be tunable, and the possible difficulties in their creation and
detection.
\\ ( http://arxiv.org/abs/0806.1201 , 19kb)
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arXiv:0806.1220
Date: Fri, 6 Jun 2008 19:59:48 GMT (400kb)

Title: Quantum-Fluctuation-Driven Coherent Spin Dynamics in Small Condensates
Authors: Xiaoling Cui, Yupeng Wang and Fei Zhou
Categories: cond-mat.other
\\
We have studied quantum spin dynamics of small condensates of cold sodium
atoms. For a condensate initially prepared in a mean field ground state, we
show that coherent spin dynamics are {\em purely} driven by quantum
fluctuations of collective spin coordinates and can be tuned by quadratic
Zeeman coupling and magnetization. These dynamics in small condensates can be
probed in a high-finesse optical cavity where temporal behaviors of excitation
spectra of a coupled condensate-photon system reveal the time evolution of
populations of atoms at different hyperfine spin states.
\\ ( http://arxiv.org/abs/0806.1220 , 400kb)
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arXiv:0805.1402 (*cross-listing*)
Date: Fri, 9 May 2008 19:47:31 GMT (216kb)

Title: QND measurements and state preparation in quantum gases by light
detection
Authors: Igor B. Mekhov, Helmut Ritsch
Categories: quant-ph cond-mat.other physics.atom-ph physics.optics
\\
We consider light scattering from ultracold atoms trapped in an optical
lattice into a cavity. The measurement of photons leaking out the cavity
Depending on the chosen geometry the time resolved light detection projects the
atomic quantum state to various atom-number squeezed and Schroedinger cat
states. Modifications of the atomic and light properties at a single quantum
trajectory are demonstrated. The quantum structure of final states can be
revealed by further observations of the same sample.
\\ ( http://arxiv.org/abs/0805.1402 , 216kb)
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arXiv:0806.1048
Date: Fri, 6 Jun 2008 19:32:20 GMT (53kb)

Title: Spin squeezing and entanglement
Authors: Geza Toth, Christian Knapp, Otfried G\"uhne, Hans J. Briegel
Categories: quant-ph
Comments: 13 pages including 6 figures and 2 tables, revtex4
\\
What is the relation between spin squeezing and entanglement? To clarify
this, we derive the full set of generalized spin squeezing inequalities for the
detection of entanglement. These are inequalities for the mean values and
variances of the collective angular momentum components J_k. They can be used
for the experimental detection of entanglement in a system of spin-1/2
particles in which the spins cannot be individually addressed. We present
various sets of inequalities that can detect all entangled states that can be
detected based on the knowledge of: (i) the mean values and variances of J_k in
three orthogonal directions, or (ii) the variances of J_k in three orthogonal
directions, or (iii) the mean values of J_k^2 in three orthogonal directions or
(iv) the mean values and variances of J_k in arbitrary directions. We compare
our inequalities to known spin squeezing entanglement criteria and discuss to
which extent spin squeezing is related to entanglement in the reduced two-qubit
states. Finally, we apply our criteria for entanglement detection in spin
models, showing that they can be used to detect bound entanglement in these
systems.
\\ ( http://arxiv.org/abs/0806.1048 , 53kb)
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arXiv:0806.1196
Date: Fri, 6 Jun 2008 16:03:57 GMT (142kb)

Title: Creating ultracold molecules by collisions with ultracold rare gas atoms
in an optical trap
Authors: P. Barletta, J. Tennyson, P. F. Barker
Categories: physics.atom-ph physics.chem-ph
Comments: 5 pages, 1 figure, 1 table, submitted for publication
\\
We study collisions of para-H$_2$ with five rare gas atomic species (He, Ne,
Ar, Kr and Xe) over the range from 1 K to 1 $\mu$ K and evaluate the
feasibility of sympathetic cooling H$_2$ with ultracold ground state rare gas
atoms co-trapped within a deep optical trap. Collision cross-sections over this
large temperature range show that all of these species could be used to cool
H$_2$ to ultracold temperatures and that argon and helium are the most
promising species for future experiments.
\\ ( http://arxiv.org/abs/0806.1196 , 142kb)
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arXiv:0806.1517
Date: Mon, 9 Jun 2008 18:47:15 GMT (842kb,D)

Title: Stirring trapped atoms into fractional quantum Hall puddles
Authors: Stefan K. Baur, Kaden R. A. Hazzard, and Erich J. Mueller (Cornell)
Categories: cond-mat.mes-hall cond-mat.other
Comments: 4 pages, 3 figures (13 subfigures)
\\
We theoretically explore the generation of few-body analogs of fractional
quantum Hall states. We consider an array of identical few-atom clusters
(n=2,3,4), each cluster trapped at the node of an optical lattice. By
temporally varying the amplitude and phase of the trapping lasers, one can
introduce a rotating deformation at each site. We analyze protocols for
coherently transferring ground state clusters into highly correlated states,
producing theoretical fidelities in excess of 99%.
\\ ( http://arxiv.org/abs/0806.1517 , 842kb)
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arXiv:0806.1295
Date: Sat, 7 Jun 2008 18:55:32 GMT (343kb)

Title: Giant formation rates of ultracold molecules via Feshbach Optimized
Photoassociation
Authors: Philippe Pellegrini, Marko Gacesa, and Robin C\^ot\'e
Categories: quant-ph
\\
Ultracold molecules offer a broad variety of applications, ranging from
metrology to quantum computing. However, forming "real" ultracold molecules,
{\it i.e.} in deeply bound levels, is a very difficult proposition. Here, we
show how photoassociation in the vicinity of a Feshbach resonance enhance
molecular formation rates by several orders of magnitude. We illustrate this
effect in heteronuclear systems, and find giant rate coefficients even in
deeply bound levels. We also give a simple analytical expression for the
photoassociation rates, and discuss future applications of the Feshbach
Optimized Photoassociation, or FOPA, technique.
\\ ( http://arxiv.org/abs/0806.1295 , 343kb)
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arXiv:0806.1479
Date: Mon, 9 Jun 2008 15:49:23 GMT (7kb)

Title: Exciton BCS or BEC state in a semiconductor bilayer system?
Authors: E. H. Martins Ferreira, Tathiana Moreira, M. C. Nemes
Categories: quant-ph
\\
We calculate the off-diagonal long range order (ODLRO) terms of the
exciton--exciton correlation function of a semiconductor bilayer system with
Coulomb interaction and a transverse magnetic field. We show that the formation
of a BEC state is very sensitive to the width of the interaction in momentum
space. This dependence is analytically derived and represents the key physical
ingredient for the formation (or not) of an exciton condensate state.
\\ ( http://arxiv.org/abs/0806.1479 , 7kb)
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arXiv:0806.1368
Date: Mon, 9 Jun 2008 03:36:56 GMT (59kb)

Title: Application of B-splines to determining eigen-spectrum of Feshbach
molecules
Authors: A. Derevianko, E. Luc-Koenig, and F. Masnou-Seeuws
Categories: physics.atom-ph physics.comp-ph
Comments: submitted to can j phys: Walter Johnson symposum
\\
The B-spline basis set method is applied to determining the rovibrational
eigen-spectrum of diatomic molecules. A particular attention is paid to a
challenging numerical task of an accurate and efficient description of the
vibrational levels near the dissociation limit (halo-state and Feshbach
molecules). Advantages of using B-splines are highlighted by comparing the
performance of the method with that of the commonly-used discrete variable
representation (DVR) approach. Several model cases, including the Morse
potential and realistic potentials with 1/R^3 and 1/R^6 long-range dependence
of the internuclear separation are studied. We find that the B-spline method is
superior to the DVR approach and it is robust enough to properly describe the
Feshbach molecules. The developed numerical method is applied to studying the
universal relation of the energy of the last bound state to the scattering
length. We numerically illustrate the validity of the quantum-defect-theoretic
formulation of such a relation for a 1/R^6 potential.
\\ ( http://arxiv.org/abs/0806.1368 , 59kb)
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arXiv:0806.1627
Date: Tue, 10 Jun 2008 10:39:49 GMT (96kb)

Title: Atom-atom correlations and relative number squeezing in dissociation of
spatially inhomogeneous molecular condensates
Authors: Magnus Ogren and K. V. Kheruntsyan
Categories: cond-mat.stat-mech cond-mat.other
\\
We study atom-atom correlations and relative number squeezing in the
dissociation of a Bose-Einstein condensate (BEC) of molecular dimers made of
either bosonic or fermionic atom pairs. Our treatment addresses the role of the
spatial inhomogeneity of the molecular BEC on the strength of correlations in
the short time limit. We obtain explicit analytic results for the
density-density correlation functions in momentum space, and show that the
correlation widths and the degree of relative number squeezing are determined
merely by the shape of the molecular condensate.
\\ ( http://arxiv.org/abs/0806.1627 , 96kb)
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arXiv:0806.1688
Date: Tue, 10 Jun 2008 15:16:44 GMT (216kb)

Title: Anyons from fermions with conventional two-body interactions
Authors: Yue Yu, Yi Li
Categories: cond-mat.other cond-mat.str-el
\\
Emergent anyonic excitations are the key elements to reach the fault-tolerant
topological quantum computation, which was first recognized by Kitaev in the
study of the toric code model. However, it is difficult to realize these toric
codes in a practical system because of unconventional interactions in the model
Hamiltonian. We propose a two-component fermion model with conventional
interaction from which anyons emerge. We show that the low-lying excitations in
this model obey the same fusion rules as those of the toric code model and the
vortices are mutual semions. After switching on the mutual component
interaction between fermions, non-abelian anyons emerge. We discuss the
possible practical systems for these anyons and found the anyons may be
observed in systems of cold dipolar Fermi atoms, e.g., Ytterbium, and cold
dipolar fermionic heteronuclear molecules, e.g., $^{40}$K$^{87}$Rb, in optical
lattice. We can create and manipulate these anyons by laser beams acting on
lattice sites.
\\ ( http://arxiv.org/abs/0806.1688 , 216kb)
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arXiv:0806.1553
Date: Tue, 10 Jun 2008 18:07:52 GMT (673kb)

Title: Amplification of Fluctuations in a Spinor Bose Einstein Condensate
Authors: S. R. Leslie, J. Guzman, M. Vengalattore, J. D. Sau, M. L. Cohen, D.
M. Stamper-Kurn
Categories: quant-ph
\\
Dynamical instabilities due to spin-mixing collisions in a $^{87}$Rb F=1
spinor Bose-Einstein condensate are used as an amplifier of quantum spin
fluctuations. We demonstrate the spectrum of this amplifier to be tunable, in
quantitative agreement with mean-field calculations. We quantify the
microscopic spin fluctuations of the initially paramagnetic condensate by
applying this amplifier and measuring the resulting macroscopic magnetization.
The magnitude of these fluctuations is consistent with predictions of a
beyond-mean-field theory. The spinor-condensate-based spin amplifier is thus
shown to be nearly quantum-limited at a gain as high as 30 dB.
\\ ( http://arxiv.org/abs/0806.1553 , 673kb)
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arXiv:0806.1697
Date: Tue, 10 Jun 2008 15:59:29 GMT (667kb)

Title: Diffraction of fast atoms and molecules from surfaces
Authors: J. R. Manson, Hocine Khemliche, Philippe Roncin
Categories: physics.atom-ph
Comments: 37 pages including 3 figures
\\
Prompted by recent experimental developments, a theory of surface scattering
of fast atoms at grazing incidence is developed. The theory gives rise to a
quantum mechanical limit for ordered surfaces that describes coherent
diffraction peaks whose thermal attenuation is governed by a Debye-Waller
factor, however, this Debye-Waller factor has values much larger than would be
calculated using simple models. A classical limit for incoherent scattering is
obtained for high energies and temperatures. Between these limiting classical
and quantum cases is another regime in which diffraction features appear that
are broadened by the motion in the fast direction of the scattered beam but
whose intensity is not governed by a Debye-Waller factor. All of these limits
appear to be accessible within the range of currently available experimental
conditions.
\\ ( http://arxiv.org/abs/0806.1697 , 667kb)
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arXiv:0806.1747
Date: Tue, 10 Jun 2008 20:19:40 GMT (171kb)

Title: Exact quantum Monte Carlo study of one dimensional trapped fermions with
attractive contact interactions
Authors: Michele Casula, D. M. Ceperley, and Erich J. Mueller
Categories: cond-mat.other cond-mat.supr-con
\\
Using exact continuous quantum Monte Carlo techniques, we study the zero and
finite temperature properties of a system of harmonically trapped one
dimensional spin 1/2 fermions with short range interactions. Motivated by
experimental searches for modulated Fulde-Ferrel-Larkin-Ovchinikov states, we
systematically examine the impact of a spin imbalance on the density profiles.
We quantify the accuracy of the Thomas-Fermi approximation, finding that for
sufficiently large particle numbers (N > 100) it quantitatively reproduces most
features of the exact density profile. The Thomas-Fermi approximation fails to
capture small Friedel-like spin and density oscillations and overestimates the
size of the fully paired region in the outer shell of the trap. Based on our
results, we suggest a range of experimentally tunable parameters to maximize
the visibility of the double shell structure of the system and the
Fulde-Ferrel-Larkin-Ovchinikov state in the one dimensional harmonic trap.
Furthermore, we analyze the fingerprints of the attractive contact interactions
in the features of the momentum and pair momentum distributions.
\\ ( http://arxiv.org/abs/0806.1747 , 171kb)
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arXiv:0806.1761
Date: Tue, 10 Jun 2008 21:57:30 GMT (39kb)

Title: Exact Ground State Energy of Hubbard Rings in the Atomic Limit
Authors: W. B. Hodge, N. A. W. Holzwarth, W. C. Kerr
Categories: cond-mat.str-el
Comments: 4 pages, 4 figure files for 3 figures
\\
Making some reasonable assumptions, we derive an expression for the ground
state energy of a one-dimensional Hubbard ring in the atomic limit, valid for
systems of finite size. In doing so, we show that a straightforward solution to
equations derived by Lieb and Wu does not obtain the expected ground state
energy in this limit.
\\ ( http://arxiv.org/abs/0806.1761 , 39kb)
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arXiv:0806.1773
Date: Wed, 11 Jun 2008 00:51:43 GMT (62kb)

Title: Exact solution for strongly interacting Fermi gases in tight waveguides
Authors: Liming Guan, Shu Chen, Yupeng Wang, Zhong-Qi Ma
Categories: cond-mat.str-el cond-mat.stat-mech
\\
We present an exact analytical solution of the fundamental systems of
quasi-one-dimensional spin-1/2 fermions with infinite repulsion for arbitrary
confining potential. The eigenfunctions are constructed by the combination of
Gireardeau's hard-core contacting boundary condition and group theoretical
method which guarantees the obtained states to be simultaneously the
eigenstates of $S$ and $S_z$ and fulfill the antisymmetry under odd
permutation. We show that the total ground-state density profile behaves like
the polarized noninteracting fermions, whereas the spin-dependent densities
display different properties for different spin configurations. We also discuss
the splitting of the ground states for large but finite repulsion.
\\ ( http://arxiv.org/abs/0806.1773 , 62kb)
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arXiv:0806.1777
Date: Wed, 11 Jun 2008 01:46:40 GMT (204kb)

Title: Spin echo in spinor dipolar Bose-Einstein condensates
Authors: Masashi Yasunaga and Makoto Tsubota
Categories: cond-mat.other
\\
We theoretically propose and numerically realize spin echo in a spinor
Bose--Einstein condensate (BEC). We investigate the influence on the spin echo
of phase separation of the condensate. The equation of motion of the spin
density exhibits two relaxation times. We use two methods to separate the
relaxation times and hence demonstrate a technique to reveal magnetic
dipole--dipole interactions in spinor BECs.
\\ ( http://arxiv.org/abs/0806.1777 , 204kb)
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arXiv:0806.1799
Date: Wed, 11 Jun 2008 09:17:21 GMT (196kb)

Title: Construction of localized atomic wave packets
Authors: S. Sree Ranjani, P. K. Panigrahi and A. K. Kapoor
Categories: cond-mat.other
\\
It is shown that highly localized solitons can be created in lower
dimensional Bose-Einstein condensates (BEC), trapped in a regular harmonic
trap, by temporally varying the trap frequency. A BEC trapped in such a trap
can be effectively used to construct a pulsed atomic laser emitting coherent
atomic wave packets. It is also shown that one has complete control over the
spatio-temporal dynamics of the solitons. The dynamics of these solitons are
compared with those constructed in a BEC where the trap frequency is constant.
\\ ( http://arxiv.org/abs/0806.1799 , 196kb)
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arXiv:0806.1885
Date: Wed, 11 Jun 2008 14:55:47 GMT (765kb)

Title: Unitary polarized Fermi gas under adiabatic rotation
Authors: I. Bausmerth, A. Recati, S. Stringari
Categories: cond-mat.other
\\
We discuss the effect of an adiabatic rotation on the phase separation
between the superfluid and normal component of a trapped polarized Fermi gas at
unitarity and zero temperature, under the assumption that quantized vortices
are not formed. We show that the Chandrasekhar-Clogston limit
$n_{\downarrow}/\n_{\uparrow}$ characterizing the local polarization in the
normal phase at the interface is enhanced by the rotation as a consequence of
the centrifugal effect. The density profiles (local and column integral) of the
two spin species are calculated as a function of the angular velocity for
different values of the polarization. The critical value of the angular
velocity at which the superfluid exhibits a spontaneous quadrupole deformation
is also calculated for the unpolarized case.
\\ ( http://arxiv.org/abs/0806.1885 , 765kb)
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arXiv:0806.1889
Date: Wed, 11 Jun 2008 14:52:36 GMT (19kb)

Title: Hydrodynamic equations of anisotropic, polarized and inhomogeneous
superfluid vortex tangles
Authors: David Jou, Maria Stella Mongiov\i, Michele Sciacca
Categories: cond-mat.other
\\
We include the effects of anisotropy and polarization in the hydrodynamics of
inhomogeneous vortex tangles, thus generalizing the well known
Hall-Vinen-Bekarevich-Khalatnikov equations, which do not take them in
consideration. These effects contribute to the mutual friction force ${\bf F}_{ns}$ between normal and superfluid components and to the vortex tension
force $\rho_s{\bf T}$. These equations are complemented by an evolution
equation for the vortex line density, which takes into account these
contributions.
\\ ( http://arxiv.org/abs/0806.1889 , 19kb)
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arXiv:0806.1789
Date: Wed, 11 Jun 2008 05:18:29 GMT (322kb)

Title: Towards a guided atom interferometer based on a superconducting atom
chip
Authors: T. Mueller, X. Wu, A. Mohan, A. Eyvazov, Y. Wu and R. Dumke
Categories: physics.atom-ph
Comments: 14 pages, 7 figures, accepted for New Journal of Physics
\\
We evaluate the realization of a novel geometry of a guided atom
interferometer based on a high temperature superconducting microstructure. The
interferometer type structure is obtained with a guiding potential realized by
two current carrying superconducting wires in combination with a closed
superconducting loop sustaining a persistent current. We present the layout and
realization of our superconducting atom chip. By employing simulations we
discuss the critical parameters of the interferometer guide in particular near
the splitting regions of the matter waves. Based on measurements of the
relevant chip properties we discuss the application of a compact and reliable
on-chip atom interferometer.
\\ ( http://arxiv.org/abs/0806.1789 , 322kb)
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arXiv:0806.1991
Date: Thu, 12 Jun 2008 03:08:20 GMT (696kb)

Title: Roton softening and supersolidity in Rb spinor condensates
Authors: R. W. Cherng, E. Demler
Categories: cond-mat.other
\\
Superfluids with a tendency towards periodic crystalline order have both a
phonon and roton like spectrum of collective modes. The softening of the roton
spectrum provides one route to a supersolid. We show that roton softening
occurs in 87Rb spinor condensates once dipolar interactions and spin dynamics
are taken into account. By including the effects of a quasi-two-dimensional
geometry and rapid Larmor precession, we show a dynamical instability develops
in the collective mode spectrum at finite wavevectors. We construct phase
diagrams showing a variety of instabilities as a function of the direction of
the magnetic field and strength of the quadratic Zeeman shift. Our results
provide a possible explanation of current experiments in the Berkeley group
Phys. Rev. Lett. 100:170403 (2008).
\\ ( http://arxiv.org/abs/0806.1991 , 696kb)
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arXiv:0806.2012
Date: Thu, 12 Jun 2008 07:09:48 GMT (261kb)

Title: Uniformly frustrated bosonic Josephson-junction arrays
Authors: Kenichi Kasamatsu
Categories: cond-mat.stat-mech cond-mat.mes-hall
\\
We derive an uniformly frustrated XY model that describes two-dimensional
Josephson junction arrays consisting of rotating Bose-Einstein condensates
trapped by both a harmonic trap and a corotating deep optical lattice. The
harmonic trap makes the coupling constant of the model have a nonuniform
parabolic dependance. We study the ground state through Monte Carlo simulations
in a wide range of the frustration parameter $f$, revealing a rich variety of
vortex patterns.
\\ ( http://arxiv.org/abs/0806.2012 , 261kb)
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arXiv:0806.2077
Date: Thu, 12 Jun 2008 13:42:38 GMT (127kb)

Title: Vortex dynamics in trapped Bose-Einstein condensate
Authors: E. J. M. Madarassy and C. F. Barenghi
Categories: cond-mat.stat-mech
Comments: 16 pages, 18 figures, accepted to JLTP
\\
We perform numerical simulations of vortex motion in a trapped Bose-Einstein
condensate by solving the two-dimensional Gross-Pitaevskii Equation in the
presence of a simple phenomenological model of interaction between the
condensate and the finite temperature thermal cloud. At zero temperature, the
trajectories of a single, off - centred vortex precessing in the condensate,
and of a vortex - antivortex pair orbiting within the trap, excite acoustic
emission. At finite temperatures the vortices move to the edge of the
condensate and vanish. By fitting the finite -temperature trajectories, we
relate the phenomenological damping parameter to the friction coefficients
$\alpha$ and $\alpha^{'}$, which are used to describe the interaction between
quantised vortices and the normal fluid in superfluid helium.
\\ ( http://arxiv.org/abs/0806.2077 , 127kb)
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arXiv:0806.2093
Date: Thu, 12 Jun 2008 15:06:36 GMT (357kb)

Title: Detuning effects in the vertical cold-atom micromaser
Authors: John Martin and Thierry Bastin
Categories: quant-ph
Journal-ref: Eur. Phys. J. D 48, 301 (2008)
DOI: 10.1140/epjd/e2008-00108-1
\\
The quantum theory of the cold atom micromaser including the effects of
gravity is established in the general case where the cavity mode and the atomic
transition frequencies are detuned. We show that atoms which classically would
not reach the interaction region are able to emit a photon inside the cavity.
The system turns out to be extremely sensitive to the detuning and in
particular to its sign. A method to solve the equations of motion for non
resonant atom-field interaction and arbitrary cavity modes is presented.
\\ ( http://arxiv.org/abs/0806.2093 , 357kb)
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arXiv:0806.1982
Date: Thu, 12 Jun 2008 00:45:47 GMT (160kb)

Title: Universal resonant ultracold molecular scattering
Authors: Vladimir Roudnev and Michael Cavagnero
Categories: physics.atom-ph physics.atm-clus
Comments: 4 pages, 4 figures, 1 table
\\
The elastic scattering amplitudes of indistinguishable, bosonic,
strongly-polar molecules possess near-threshold resonance features that can be
tuned with an applied electric field. An adiabatic description of ultracold
collisions of field-aligned molecules provides an elementary and complete
interpretation and classification of these resonant states; including three
series of threshold bound states, shape resonances, and mixed Feshbach/shape
resonances. Small tunneling amplitudes for the resonant states result in strong
correlations between the magnitude of total elastic cross sections and the
isotropy, or lack thereof, of threshold differential cross-sections.
Implications of universal scaling for the formation and trapping of dilute
quantum degenerate gases are discussed.
\\ ( http://arxiv.org/abs/0806.1982 , 160kb)
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The replacements:

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arXiv:0805.1507
replaced with revised version Thu, 5 Jun 2008 21:58:43 GMT (265kb)

Title: Maximizing the Neel temperature of fermions in a simple-cubic optical
lattice
Authors: C.J.M. Mathy and David A. Huse
Categories: cond-mat.str-el
Comments: 4 pages, 3 figures, minor changes
\\ ( http://arxiv.org/abs/0805.1507 , 265kb)
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arXiv:0709.2924
replaced with revised version Fri, 6 Jun 2008 00:54:24 GMT (47kb)

Title: Feshbach resonances in ultracold ^{6,7}Li + ^{23}Na atomic mixtures
Authors: Marko Gacesa, Philippe Pellegrini, and Robin C\^ot\'e
Categories: physics.atom-ph
\\ ( http://arxiv.org/abs/0709.2924 , 47kb)
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arXiv:cond-mat/0405182
replaced with revised version Sat, 7 Jun 2008 02:43:52 GMT (196kb)

Title: Vortex lattice stability and phase coherence in three-dimensional
rapidly rotating Bose condensates
Authors: S. Andrew Gifford, Gordon Baym
Categories: cond-mat.soft cond-mat.stat-mech
Comments: 10 pages, 2 figures, Changes include the addition of the particle
density - vortex density coupling and the correct value of the shear modulus
Journal-ref: Phys. Rev. A 70, 033602 (2004)
\\ ( http://arxiv.org/abs/cond-mat/0405182 , 196kb)
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arXiv:0712.0880
replaced with revised version Mon, 9 Jun 2008 04:33:43 GMT (248kb)

Title: New Density Wave Ground States and Dynamical Phase Transitions in an
Optical Lattice
Authors: Manan Vyas, Priyam Das, and Prasanta K. Panigrahi
Categories: cond-mat.other
\\ ( http://arxiv.org/abs/0712.0880 , 248kb)
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arXiv:0804.1277
replaced with revised version Sun, 8 Jun 2008 15:17:01 GMT (8kb)

Title: Hydrodynamics of Bose and Fermi superfluids at zero temperature: the
superfluid nonlinear Schrodinger equation
Authors: Luca Salasnich (CNR-INFM and CNISM, University of Padua)
Categories: cond-mat.stat-mech cond-mat.other
Comments: 4 pages, no figures, prepared for the Special Issue of Laser Physics:
Physics of Cold Trapped Atoms; in the second version corrected some typos
\\ ( http://arxiv.org/abs/0804.1277 , 8kb)
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arXiv:0712.0880
replaced with revised version Tue, 10 Jun 2008 04:47:08 GMT (248kb)

Title: New Density Wave Ground States and Dynamical Phase Transitions in an
Optical Lattice
Authors: Manan Vyas, Priyam Das, and Prasanta K. Panigrahi
Categories: cond-mat.other
\\ ( http://arxiv.org/abs/0712.0880 , 248kb)
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arXiv:0803.4352
replaced with revised version Tue, 10 Jun 2008 12:15:58 GMT (282kb,D)

Title: Experimental observation of oscillating and interacting matter wave dark
solitons
Authors: A. Weller, J.P. Ronzheimer, C. Gross, D.J. Frantzeskakis, G.
Theocharis, P.G. Kevrekidis, J. Esteve, and M.K. Oberthaler
Categories: quant-ph cond-mat.other
\\ ( http://arxiv.org/abs/0803.4352 , 282kb)
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arXiv:0805.3663
replaced with revised version Tue, 10 Jun 2008 17:10:19 GMT (513kb)

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
\\ ( http://arxiv.org/abs/0805.3663 , 513kb)
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arXiv:0801.1815
replaced with revised version Wed, 11 Jun 2008 13:18:49 GMT (40kb)

Title: Superfluid pairing between fermions with unequal masses
Authors: M.A. Baranov, C. Lobo, and G.V. Shlyapnikov
Categories: cond-mat.other cond-mat.supr-con
\\ ( http://arxiv.org/abs/0801.1815 , 40kb)
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arXiv:0804.2610
replaced with revised version Wed, 11 Jun 2008 13:55:38 GMT (64kb)

Title: Phase diagram and binding energy of interacting Bose gases
Authors: M. M\"annel, K. Morawetz, M. Schreiber, P. Lipavsk\'y
Categories: cond-mat.stat-mech
\\ ( http://arxiv.org/abs/0804.2610 , 64kb)
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arXiv:physics/0701272
replaced with revised version Tue, 10 Jun 2008 20:15:38 GMT (659kb)

Title: Experimental single-impulse magnetic focusing of launched cold atoms
Authors: David A. Smith, Aidan S. Arnold, Matthew J. Pritchard and Ifan G.
Hughes
Categories: physics.atom-ph physics.optics
Comments: Revised to incorporate referee suggestions, final version
Journal-ref: J. Phys. B 41, 125302 (2008)
DOI: 10.1088/0953-4075/41/12/125302
\\ ( http://arxiv.org/abs/physics/0701272 , 659kb)
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arXiv:0804.2068
replaced with revised version Thu, 12 Jun 2008 09:50:27 GMT (150kb)

Title: Self-trapping of Bose-Einstein condensates expanding into shallow
optical lattices
Authors: M. Rosenkranz, D. Jaksch, F. Y. Lim, W. Bao
Categories: quant-ph cond-mat.other
Comments: 7 pages, 5 figures, RevTeX4. Published version. Changed title, minor
references
Journal-ref: Phys. Rev. A 77, 063607 (2008)
DOI: 10.1103/PhysRevA.77.063607
\\ ( http://arxiv.org/abs/0804.2068 , 150kb)
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Till next time,
Matt.

--
=========================================================================
Dr M. J. Davis,               Senior Lecturer in Physics
School of Physical Sciences,  email: mdavis_at_physics.uq.edu.au
University of Queensland,     ph   : +61 7 334 69824
Brisbane, QLD 4072,           fax  : +61 7 336 51242
Australia.                    http://www.physics.uq.edu.au/people/mdavis/
=========================================================================
Matt's arXiv selection: weekly summary of cold-atom papers from arXiv.org
http://www.physics.uq.edu.au/people/mdavis/matts_arXiv/
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Received on Fri Jul 04 2008 - 08:30:56 EST

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