Dear subscribers,
Thanks for all the supportive emails. I will be continuing Matt's arXiv and
have set up a schedule in order to try to keep up to date. We should be back on
track in the next week.
This week's selection was compiled by Geoff Lee, and contains 29 new abstracts
and 12 replacements.
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arXiv:0910.0052 (*cross-listing*)
Date: Wed, 30 Sep 2009 23:17:56 GMT (263kb)
Date (revised v2): Mon, 10 May 2010 18:51:05 GMT (264kb)
Title: Stability of a Fully Polarized Ultracold Fermi Gas near Zero-Crossing of
a p-wave Feshbach Resonance
Authors: N. T. Zinner
Categories: cond-mat.quant-gas quant-ph
Comments: Published version, 6 pages, 2 figures
Journal-ref: Eur. Phys. J. D 57, 235 (2010)
DOI: 10.1140/epjd/e2010-00047-2
\\
We consider a fully polarized ultracold Fermi gas interacting through a
p-wave Feshbach resonance. Using a two-channel model, we find the effective
potential at the point where the p-wave scattering length goes to zero. Here
the effective interaction provides attraction and one can therefore ask about
the stability of the system. We calculate the energy density of the system in
the Thomas-Fermi approximation, determine the profile of the gas, and the
critical number of particle in the system as function of the relevant
interaction parameters. The instability can be deduced from a simple breathing
mode argument which explains the scaling found numerically. The critical
particle number turns out to be extremely large unless the external confinement
is very tight. We therefore conclude that the effect is insignificant for
standard trapping potentials and that the magnetic dipole interaction is the
important term at zero scattering length. However, for tight confinement as in
an optical lattice higher-order corrections can become important.
\\ ( http://arxiv.org/abs/0910.0052 , 264kb)
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arXiv:1001.3250 (*cross-listing*)
Date: Tue, 19 Jan 2010 13:27:10 GMT (982kb)
Date (revised v2): Tue, 11 May 2010 18:21:02 GMT (985kb)
Title: Three-dimensional Roton-Excitations and Supersolid formation in
Rydberg-excited Bose-Einstein Condensates
Authors: N. Henkel, R. Nath, T. Pohl
Categories: physics.atom-ph cond-mat.quant-gas
Comments: 4 pages, 5 figures
Journal-ref: Phys. Rev. Lett. 104, 195302 (2010)
DOI: 10.1103/PhysRevLett.104.195302
\\
We study the behavior of a Bose-Einstein condensate in which atoms are weakly
coupled to a highly excited Rydberg state. Since the latter have very strong
van der Waals interactions, this coupling induces effective, nonlocal
interactions between the dressed ground state atoms, which, opposed to dipolar
interactions, are isotropically repulsive. Yet, one finds partial attraction in
momentum space, giving rise to a roton-maxon excitation spectrum and a
transition to a supersolid state in three-dimensional condensates. A detailed
analysis of decoherence and loss mechanisms suggests that these phenomena are
observable with current experimental capabilities.
\\ ( http://arxiv.org/abs/1001.3250 , 985kb)
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arXiv:1005.1138
Date: Fri, 7 May 2010 06:11:11 GMT (682kb,D)
Title: Manipulation of coherent atom waves using accelerated two-dimensional
optical lattices
Authors: Wei-Chih Ting, Dian-Jiun Han, and Shin-Tza Wu
Categories: cond-mat.quant-gas
Comments: Figures with low resolution; high quality ones can be supplied on
request
\\
We study the dynamics of Bose-Einstein condensates in accelerated
two-dimensional optical square lattices by numerically solving the
Gross-Pitaevskii equation. We consider the regime with negligible mean-field
interactions and examine in detail the pulses of atom clouds ejected from the
condensate due to Landau-Zener tunnelling. The pulses exhibit patterned
structures that can be understood from the momentum-space dynamics of the
condensate. Aside from conceiving realization of a pulsed two-dimensional atom
laser, we demonstrate that, by exploring the band structure of the lattice,
Landau-Zener tunnelling and Bragg reflection of the condensate inside the
optical lattice can provide means for manipulation of coherent atom waves. This
result shall be valuable for beam splitting in atom interferometry and possibly
also for quantum information sciences.
\\ ( http://arxiv.org/abs/1005.1138 , 682kb)
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arXiv:1005.1158
Date: Fri, 7 May 2010 08:58:56 GMT (23kb)
Title: Temperature and coupling dependence of the "contact" for an ultracold
Fermi gas
Authors: F. Palestini, A. Perali, P. Pieri, G. C. Strinati
Categories: cond-mat.quant-gas
Comments: 4 pages, 3 figures
\\
Physical properties of an ultracold Fermi gas in the temperature-coupling
phase diagram can be characterized by the "contact" C, which enters the
pair-correlation function at short distances and describes how the two-body
problem merges into its surrounding. We show that the local order established
by pairing fluctuations about the critical temperature Tc of the superfluid
transition considerably enhances the contact C in a temperature range where
pseudogap phenomena are maximal. Our results for C in a trap compare well with
recently available experimental data. A detailed analysis is also provided for
the effects that trap averaging has on the values of C.
\\ ( http://arxiv.org/abs/1005.1158 , 23kb)
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arXiv:1005.1190 (*cross-listing*)
Date: Fri, 7 May 2010 12:14:23 GMT (8kb)
Title: Stochastic process behind nonlinear thermodynamic quantum master
equation
Authors: Hans Christian \"Ottinger
Categories: quant-ph cond-mat.stat-mech
Comments: 4 pages
\\
We propose a piecewise deterministic Markovian jump process in Hilbert space
such that the covariance matrix of this stochastic process solves the
thermodynamic quantum master equation. The proposed stochastic process is
particularly simple because the normalization of the vectors in Hilbert space
is preserved only on average. As a consequence of the nonlinearity of the
thermodynamic master equation, the construction of stochastic trajectories
involves the density matrix as a running ensemble average. We identify a
principle of detailed balance and a fluctuation-dissipation relation for our
Markovian jump process.
\\ ( http://arxiv.org/abs/1005.1190 , 8kb)
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arXiv:1005.1262
Date: Fri, 7 May 2010 17:41:46 GMT (3011kb)
Title: Vortex Dynamics in Anisotropic Traps
Authors: S. McEndoo and Th. Busch
Categories: cond-mat.quant-gas
Comments: 6 pages, 6 figures
\\
We investigate the dynamics of linear vortex lattices in anisotropic traps in
two-dimensions and show that the interplay between the rotation and the
anisotropy leads to a rich but highly regular dynamics.
\\ ( http://arxiv.org/abs/1005.1262 , 3011kb)
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arXiv:1005.1270
Date: Fri, 7 May 2010 18:19:52 GMT (70kb)
Title: Supersolid and charge density-wave states from anisotropic interaction
in an optical lattice
Authors: Y.-H. Chan, Y.-J. Han, L.-M. Duan
Categories: cond-mat.quant-gas cond-mat.str-el
Comments: 5 pages, 5 figures.
\\
We show anisotropy of the dipole interaction between magnetic atoms or polar
molecules can stabilize new quantum phases in an optical lattice. Using a well
controlled numerical method based on the tensor network algorithm, we calculate
phase diagram of the resultant effective Hamiltonian in a two-dimensional
square lattice - an anisotropic Hubbard model of hard-core bosons with
attractive interaction in one direction and repulsive interaction in the other
direction. Besides the conventional superfluid and the Mott insulator states,
we find the striped and the checkerboard charge density wave states and the
supersolid phase that interconnect the superfluid and the striped solid states.
The transition to the supersolid phase has a mechanism different from the case
of the soft-core Bose Hubbard model.
\\ ( http://arxiv.org/abs/1005.1270 , 70kb)
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arXiv:1005.1276
Date: Fri, 7 May 2010 19:09:35 GMT (8098kb,D)
Title: Multi-Component Quantum Gases in Spin-Dependent Hexagonal Lattices
Authors: Parvis Soltan-Panahi, Julian Struck, Philipp Hauke, Andreas Bick,
Wiebke Plenkers, Georg Meineke, Christoph Becker, Patrick Windpassinger,
Maciej Lewenstein, and Klaus Sengstock
Categories: cond-mat.quant-gas quant-ph
Comments: 9 pages, 5 figures
\\
Periodicity is one of the most fundamental structural characteristics of
systems occurring in nature. The properties of these systems depend strongly on
the symmetry of the underlying periodic structure. In solid state materials -
for example - the static and transport properties as well as the magnetic and
electronic characteristics are crucially influenced by the crystal symmetry. In
this context, hexagonal structures play an extremely important role and lead to
novel physics like that of carbon nanotubes or graphene. Here we report on the
first realization of ultracold atoms in a spin-dependent optical lattice with
hexagonal symmetry. We show how combined effects of the lattice and
interactions between atoms lead to a forced antiferromagnetic N\'eel order when
two spin-components localize at different lattice sites. We also demonstrate
that the coexistence of two components - one Mott-insulating and the other one
superfluid - leads to the formation of a forced supersolid. Our observations
are consistent with theoretical predictions using Gutzwiller mean-field theory.
\\ ( http://arxiv.org/abs/1005.1276 , 8098kb)
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arXiv:1005.1309
Date: Fri, 7 May 2010 23:18:54 GMT (1081kb)
Title: Suppression of Density Fluctuations in a Quantum Degenerate Fermi Gas
Authors: Christian Sanner, Edward J. Su, Aviv Keshet, Ralf Gommers, Yong-il
Shin, Wujie Huang, Wolfgang Ketterle
Categories: cond-mat.quant-gas physics.atom-ph
\\
We study density profiles of an ideal Fermi gas and observe Pauli suppression
of density fluctuations for cold clouds deep in the quantum degenerate regime.
Strong suppression of shot noise was observed for probe volumes containing more
than 10,000 atoms. Atom noise provides sensitive thermometry at low
temperatures. The Poissonian noise of a hot cloud provides a direct and
accurate calibration of the optical resolution and absorption cross section.
After this method of sensitive noise measurements has been validated with an
ideal Fermi gas, it can now be applied to characterize phase transitions in
strongly correlated many-body systems.
\\ ( http://arxiv.org/abs/1005.1309 , 1081kb)
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arXiv:1005.1363
Date: Sun, 9 May 2010 04:19:37 GMT (20kb)
Title: A Composite Fermion Approach to the Ultracold Dilute Fermi Gas
Authors: M. A. Cazalilla
Categories: cond-mat.quant-gas cond-mat.stat-mech cond-mat.str-el
Comments: 9 pages, no figures
\\
It is argued that the recently observed Fermi liquids in strongly interacting
ultracold Fermi gases are adiabatically connected to a projected Fermi gas.
This conclusion is reached by constructing a set of Jastrow wavefunctions,
following Tan's observations on the structure of the physical Hilbert space
[Annals of Physics 323, 2952 (2008)]. The Jastrow projection merely implements
the Bethe-Peierls condition on the BCS and Fermi gas wavefunctions. This
procedure provides a simple picture of the emergence of Fermi polarons as
composite fermions in the normal state of the highly polarized gas. It is also
shown that the projected BCS wavefunction can be written as a condensate of
pairs of composite fermions (or Fermi polarons). A Hamiltonian for the
composite fermions is derived. Within a mean-field theory, it is shown that the
ground state and excitations of this Hamiltonian are those of a non-interacting
Fermi gas although they are described by Jastrow-Slater wavefunctions.
\\ ( http://arxiv.org/abs/1005.1363 , 20kb)
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arXiv:1005.1399
Date: Sun, 9 May 2010 14:07:28 GMT (33kb)
Title: Simulating Wess-Zumino Supersymmetry Model in Optical Lattices
Authors: Yue Yu and Kun Yang
Categories: cond-mat.quant-gas hep-th
Comments: 4 pages, 1 figure
\\
We study a cold atom-molecule mixture in two-dimensional optical lattices, in
which fermionic atoms have a Dirac-type dispersion. We show that by fine-tuning
the atomic and molecular interactions, such mixtures can simulate Wess-Zumino
supersymmetry (SUSY) model, the first example of SUSY theories. At zero
temperature, SUSY is not spontaneously broken for this simplest SUSY model,
which implies identical relativistic dispersions of the atom and its
superpartner, bosonic diatom molecule. This defining signature of SUSY can be
probed by single particle spectroscopies. Thermal breaking of SUSY at finite
temperature is accompanied by a thermal Goldstone fermion, i.e., phonino
excitation. This and other signatures of broken SUSY can also be probed
experimentally.
\\ ( http://arxiv.org/abs/1005.1399 , 33kb)
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arXiv:1005.1436
Date: Mon, 10 May 2010 02:15:12 GMT (785kb)
Title: Light trapping in high-density ultracold atomic gases for quantum memory
applications
Authors: I.M. Sokolov, D.V. Kupriyanov, R.G. Olave, and M.D. Havey
Categories: quant-ph cond-mat.quant-gas physics.atom-ph
Comments: Submitted to Journal of Modern Optics, Special 2010 PQE Issue
\\
High-density and ultracold atomic gases have emerged as promising media for
storage of individual photons for quantum memory applications. In this paper we
provide an overview of our theoretical and experimental efforts in this
direction, with particular attention paid to manipulation of light storage (a)
through complex recurrent optical scattering processes in very high density
gases (b) by an external control field in a characteristic electromagnetically
induced transparency configuration.
\\ ( http://arxiv.org/abs/1005.1436 , 785kb)
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arXiv:1005.1549
Date: Fri, 7 May 2010 07:59:45 GMT (12kb)
Title: Onset Properties of Supersolid Helium
Authors: Yongle Yu
Categories: cond-mat.supr-con
Comments: 3 pages, 2 fiugres
\\
Supersolid helium has a rather low transition temperature and a small
critical velocity, compared with liquid helium. These properties could be
explained in terms of helium's spectrum structure and quantum jumps involving
large momentum transfer. A grain in the solid helium possess valleys (local
minima) in its many-body dispersion curve, and an exchange of large momenta
with the grain's surroundings occurs in a jump between a level in one valley
and another level in the neighboring valley. Such jump process also naturally
causes dissipation accompanying the onset of supersolidity.
\\ ( http://arxiv.org/abs/1005.1549 , 12kb)
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arXiv:1005.1562
Date: Mon, 10 May 2010 14:28:24 GMT (108kb)
Title: Entangling two Bose Einstein condensates in a double cavity system
Authors: Tarun Kumar, Aranya B Bhattacherjee and ManMohan
Categories: cond-mat.quant-gas
Comments: 3 figures
\\
We propose a scheme to transfer the quantum state of light fields to the
collective density excitations of a Bose Einstein condensate (BEC) in a cavity.
This scheme allows to entangle two BECs in a double cavity setup by
transferring the quantum entanglement of two light fields produced from a
nondegenerate parametric amplifier (NOPA) to the collective density excitations
of the two BECs. An EPR state of the collective density excitations can be
created by a judicious choice of the system parameters.
\\ ( http://arxiv.org/abs/1005.1562 , 108kb)
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arXiv:1005.1812
Date: Tue, 11 May 2010 12:15:48 GMT (689kb,D)
Title: Absence of pairing in atomic Fermi gases
Authors: J. J. Kinnunen
Categories: cond-mat.quant-gas quant-ph
Comments: Not submitted to any journal. Manuscript sent here for peer preview.
All questions, comments, and critique highly appreciated.
\\
Pairing of atoms is a central paradigm in the studies of ultracold Fermi
atomic gases. For a gas with attractive interactions, the pairing comes in the
form of BCS pairing in the superfluid phase or as preformed pairs in the
pseudogap phase, and as formation of molecules in the presence of two-body
bound states. In this work I show that the main experiments used for measuring
the pair binding energy in atomic Fermi gases can be easily explained using a
theory which makes no reference to bound pairs of atoms.
\\ ( http://arxiv.org/abs/1005.1812 , 689kb)
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arXiv:1005.1872
Date: Tue, 11 May 2010 16:00:43 GMT (202kb)
Title: Nonequilibrium dynamical mean-field calculations based on the
non-crossing approximation and its generalizations
Authors: Martin Eckstein and Philipp Werner
Categories: cond-mat.str-el
Comments: 14 pages, 9 figures
\\
We solve the impurity problem which arises within nonequilibrium dynamical
mean-field theory for the Hubbard model by means of a self-consistent
perturbation expansion around the atomic limit. While the lowest order, known
as the non-crossing approximation (NCA), is reliable only when the interaction
U is much larger than the bandwidth, low-order corrections to the NCA turn out
to be sufficient to reproduce numerically exact Monte Carlo results in a wide
parameter range that covers the insulating phase and the metal-insulator
crossover regime at not too low temperatures. As an application of the
perturbative strong-coupling impurity solver we investigate the response of the
double occupancy in the Mott insulating phase of the Hubbard model to a
dynamical change of the interaction or the hopping, a technique which has been
used as a probe of the Mott insulating state in ultracold fermionic gases.
\\ ( http://arxiv.org/abs/1005.1872 , 202kb)
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arXiv:1005.1897
Date: Tue, 11 May 2010 17:57:09 GMT (1724kb)
Title: Single vortex-antivortex pair in an exciton polariton condensate
Authors: Georgios Roumpos, Michael D. Fraser, Andreas L\"offler, Sven
H\"ofling, Alfred Forchel and Yoshihisa Yamamoto
Categories: cond-mat.quant-gas
\\
In a homogeneous two-dimensional system at non-zero temperature, although
there can be no ordering of infinite range, a superfluid phase is predicted for
a Bose liquid. The stabilization of phase in this superfluid regime is achieved
by the formation of bound vortex-antivortex pairs. It is believed that several
different systems share this common behaviour, when the parameter describing
their ordered state has two degrees of freedom, and the theory has been tested
for some of them. However, there has been no direct experimental observation of
the phase stabilization mechanism by a bound pair. Here we present an
experimental technique that can identify a single vortex-antivortex pair in a
two-dimensional exciton polariton condensate. The pair is generated by the
inhomogeneous pumping spot profile, and is revealed in the time-integrated
phase maps acquired using Michelson interferometry, which show that the
condensate phase is only locally disturbed. Numerical modelling based on open
dissipative Gross-Pitaevskii equation suggests that the pair evolution is quite
different in this non-equilibrium system compared to atomic condensates. Our
results demonstrate that the exciton polariton condensate is a unique system
for studying two-dimensional superfluidity in a previously inaccessible regime.
\\ ( http://arxiv.org/abs/1005.1897 , 1724kb)
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arXiv:1005.1906
Date: Tue, 11 May 2010 18:38:38 GMT (93kb)
Title: Reentrant transition of bosons in a quasiperiodic potential
Authors: A. Cetoli, E. Lundh
Categories: cond-mat.quant-gas
Comments: Accepted for publication in EPL
\\
We investigate the behavior of a two dimensional array of Bose-Einstein
condensate tubes described by means of a Bose-Hubbard Hamiltonian. Using a
Wannier function expansion for the wavefunction in each tube, we compute the
Bose-Hubbard parameters related to two different longitudinal potentials,
periodic and quasiperiodic. We predict that - upon increasing the external
potential strength along the direction of the tubes - the condensate can
experience a reentrant transition between a Mott insulating phase and the
superfluid one.
\\ ( http://arxiv.org/abs/1005.1906 , 93kb)
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arXiv:1005.1915
Date: Tue, 11 May 2010 19:17:08 GMT (552kb)
Title: Analytical and numerical study of trapped strongly correlated bosons in
two- and three-dimensional lattices
Authors: Itay Hen and Marcos Rigol
Categories: cond-mat.quant-gas
Comments: 14 pages, 14 figures.
\\
We study the ground-state properties of trapped inhomogeneous systems of
hardcore bosons in two- and three-dimensional lattices. We obtain our results
both numerically, using quantum Monte Carlo techniques, and via several
analytical approximation schemes, such as the Gutzwiller-mean-field approach, a
cluster-mean-field method and a spin-wave analysis which takes quantum
fluctuations into account. We first study the homogeneous case, for which
simple analytical expressions are obtained for all observables of interest, and
compare the results with the numerical ones. We obtain the equation of state of
the system along with other thermodynamic properties such as the free energy,
kinetic energy, superfluid density, condensate fraction and compressibility. In
the presence of a trap, superfluid and insulating domains coexist in the
system. We show that the spin-wave-based method reproduces the quantum
Monte-Carlo results for global as well as for local quantities with a high
degree of accuracy. We also discuss the validity of the local density
approximation in those systems. Our analysis can be used to describe bosons in
optical lattices where the onsite interaction U is much larger than the hopping
amplitude t.
\\ ( http://arxiv.org/abs/1005.1915 , 552kb)
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arXiv:1005.1922
Date: Tue, 11 May 2010 19:52:51 GMT (1781kb,D)
Title: Enhanced and reduced atom number fluctuations in a BEC splitter
Authors: Kenneth Maussang, G. Edward Marti, Tobias Schneider, Philipp
Treutlein, Yun Li, Alice Sinatra, Romain Long, J\'er\^ome Est\`eve, Jakob
Reichel
Categories: quant-ph cond-mat.quant-gas
\\
We measure atom number statistics after splitting a gas of ultracold 87Rb
atoms in a purely magnetic double-well potential created on an atom chip. Well
below the critical temperature for Bose-Einstein condensation T_c, we observe
reduced fluctuations down to -4.9dB below the atom shot noise level.
Fluctuations rise to more than +3.8dB close to T_c, before reaching the shot
noise level for higher temperatures. We use two-mode and classical field
simulations to model these results. This allows us to confirm that the
super-shot noise fluctuations directly originate from quantum statistics.
\\ ( http://arxiv.org/abs/1005.1922 , 1781kb)
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arXiv:1005.1963
Date: Tue, 11 May 2010 22:27:07 GMT (318kb)
Title: Two-dimensional expansion of a condensed dense Bose gas
Authors: E.S. Annibale, A. Gammal, K. Ziegler
Categories: cond-mat.quant-gas nlin.PS
Comments: 5 pages, 8 figures
\\
We study the expansion dynamics of a condensate in a strongly interacting
Bose gas in the presence of an obstacle. Our focus is on the generation of
shock waves after the Bose gas has passed the obstacle. The strongly
interacting Bose gas is described in the slave-boson representation. A
saddle-point approximation provides a nonlinear equation of motion for the
macroscopic wave function, analogous to the Gross-Pitaevskii equation of a
weakly interacting Bose gas but with different nonlinearity. We compare the
results with the Gross-Pitaevskii dynamics of a weakly interacting Bose gas and
find a similar behavior with a slower behavior of the strongly interacting
system.
\\ ( http://arxiv.org/abs/1005.1963 , 318kb)
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arXiv:1005.1990
Date: Wed, 12 May 2010 05:12:05 GMT (33kb,D)
Title: Beyond universality in three-body recombination: an Effective Field
Theory treatment
Authors: C. Ji, L. Platter, D. R. Phillips
Categories: cond-mat.quant-gas nucl-th quant-ph
Comments: 14 pages, 4 figures
Report-no: INT-PUB-10-020, HISKP-TH-10-11
\\
We discuss the impact of a finite effective range on three-body systems
interacting through a large two-body scattering length. By employing a
perturbative analysis in an effective field theory well-suited to this scale
hierarchy we find that an additional three-body parameter is required for
consistent renormalization once range corrections are considered. This allows
us to extend previously discussed universal relations between different
observables in the recombination of cold atoms to account for the presence of a
finite effective range. We show that such range corrections improve the
agreement with experimental data for Lithium-7 data obtained by the Bar-Ilan
group. They cannot, however, explain the relationship between positive- and
negative-scattering-length data on Lithium-7 recombination taken by the Rice
group.
\\ ( http://arxiv.org/abs/1005.1990 , 33kb)
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arXiv:1005.2011
Date: Wed, 12 May 2010 07:40:02 GMT (116kb)
Title: Parametric amplification of matter waves in dipolar spinor Bose-Einstein
condensates
Authors: F. Deuretzbacher, G. Gebreyesus, O. Topic, M. Scherer, B. L\"ucke, W.
Ertmer, J. Arlt, C. Klempt, L. Santos
Categories: cond-mat.quant-gas
\\
Spin-changing collisions may lead under proper conditions to the parametric
amplification of matter waves in spinor Bose-Einstein condensates. Magnetic
dipole-dipole interactions, although typically very weak in alkaline atoms, are
shown to play a very relevant role in the amplification process. We show that
these interactions may lead to a strong dependence of the amplification
dynamics on the angle between the trap axis and the magnetic-field orientation.
We analyze as well the important role played by magnetic-field gradients, which
modify also strongly the amplification process. Magnetic-field gradients must
be hence carefully controlled in future experiments, in order to observe
clearly the effects of the dipolar interactions in the amplification dynamics.
\\ ( http://arxiv.org/abs/1005.2011 , 116kb)
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arXiv:1005.2069
Date: Wed, 12 May 2010 12:22:50 GMT (482kb)
Title: The Generation, Evolution and Decay of Pure Quantum Turbulence: A Full
Biot-Savart Simulation
Authors: Shoji Fujiyama, Akira Mitani, Makoto Tsubota, David I. Bradley, Shaun
N. Fisher, Anthony M. Guenault, Richard P. Haley, George R. Pickett and
Viktor Tsepelin
Categories: cond-mat.other cond-mat.quant-gas
Comments: 5 pages, 4 figures, accepted for PRB Rapid Communications (11May2010)
\\
A zero temperature superfluid is arguably the simplest system in which to
study complex fluid dynamics, such as turbulence. We describe computer
simulations of such turbulence and compare the results directly with recent
experiments in superfluid 3He-B. We are able to follow the entire process of
the production, evolution, and decay of quantum turbulence. We find striking
agreement between simulation and experiment and gain new insights into the
mechanisms involved.
\\ ( http://arxiv.org/abs/1005.2069 , 482kb)
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arXiv:1005.2153
Date: Wed, 12 May 2010 16:56:07 GMT (1065kb)
Title: Coherent excitation of a single atom to a Rydberg state
Authors: Y. Miroshnychenko, A. Ga\"etan, C. Evellin, P. Grangier, D. Comparat,
P. Pillet, T. Wilk, and A. Browaeys
Categories: quant-ph
\\
We present the coherent excitation of a single Rubidium atom to the Rydberg
state (58d3/2) using a two-photon transition. The experimental setup is
described in detail, as well as experimental techniques and procedures. The
coherence of the excitation is revealed by observing Rabi oscillations between
ground and Rydberg states of the atom. We analyze the observed oscillations in
detail and compare them to numerical simulations which include imperfections of
our experimental system. Strategies for future improvements on the coherent
manipulation of a single atom in our settings are given.
\\ ( http://arxiv.org/abs/1005.2153 , 1065kb)
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arXiv:1005.2203
Date: Wed, 12 May 2010 20:40:38 GMT (53kb)
Title: BECs on slightly asymmetric double-well potentials
Authors: B. Julia-Diaz, J. Martorell, A. Polls
Categories: cond-mat.quant-gas
Comments: 6 pages, 4 figures, to appear in Phys. Rev. A
\\
An analytical insight into the symmetry breaking mechanisms underlying the
transition from Josephson to self-trapping regimes in Bose-Einstein condensates
is presented. We obtain expressions for the ground state properties of the
system of a gas of attractive bosons modelized by a two site Bose-Hubbard
hamiltonian with an external bias. Simple formulas are found relating the
appearance of fragmentation in the condensate with the large quantum
fluctuations of the population imbalance occurring in the transition from the
Josephson to the self-trapped regime.
\\ ( http://arxiv.org/abs/1005.2203 , 53kb)
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arXiv:1005.2366
Date: Thu, 13 May 2010 16:05:02 GMT (676kb,D)
Title: Competition between pairing and ferromagnetic instabilities in ultracold
Fermi gases near Feshbach resonances
Authors: David Pekker, Mehrtash Babadi, Rajdeep Sensarma, Nikolaj Zinner, Lode
Pollet, Martin W. Zwierlein, Eugene Demler
Categories: cond-mat.quant-gas
Comments: 4+epsilon pages, 4 figures
\\
We study the quench dynamics of a two-component ultracold Fermi gas from the
weak into the strong interaction regime, where the short time dynamics are
governed by the exponential growth rate of unstable collective modes. We obtain
an effective interaction that takes into account both Pauli blocking and the
energy dependence of the scattering amplitude near a Feshbach resonance. Using
this interaction we analyze the competing instabilities towards Stoner
ferromagnetism and pairing.
\\ ( http://arxiv.org/abs/1005.2366 , 676kb)
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arXiv:1005.2389 (*cross-listing*)
Date: Thu, 13 May 2010 18:35:29 GMT (32kb)
Title: Basic zeta functions and some applications in physics
Authors: Klaus Kirsten
Categories: hep-th math-ph math.MP quant-ph
Comments: To appear in "A Window into Zeta and Modular Physics", Mathematical
Sciences Research Institute Publications, Vol. 57, 2010, Cambridge University
Press
\\
It is the aim of these lectures to introduce some basic zeta functions and
their uses in the areas of the Casimir effect and Bose-Einstein condensation. A
brief introduction into these areas is given in the respective sections. We
will consider exclusively spectral zeta functions, that is zeta functions
arising from the eigenvalue spectrum of suitable differential operators. There
is a set of technical tools that are at the very heart of understanding
analytical properties of essentially every spectral zeta function. Those tools
are introduced using the well-studied examples of the Hurwitz, Epstein and
Barnes zeta function. It is explained how these different examples of zeta
functions can all be thought of as being generated by the same mechanism,
namely they all result from eigenvalues of suitable (partial) differential
operators. It is this relation with partial differential operators that
provides the motivation for analyzing the zeta functions considered in these
lectures. Motivations come for example from the questions "Can one hear the
shape of a drum?" and "What does the Casimir effect know about a boundary?".
Finally "What does a Bose gas know about its container?"
\\ ( http://arxiv.org/abs/1005.2389 , 32kb)
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\\
arXiv:1005.2403
Date: Thu, 13 May 2010 19:49:15 GMT (477kb,D)
Title: A superfluid-droplet crystal and a free-space supersolid in a
dipole-blockaded gas
Authors: F. Cinti, P. Jain, M. Boninsegni, A. Micheli, P. Zoller, and G.
Pupillo
Categories: cond-mat.quant-gas cond-mat.stat-mech
Comments: 4 pages, 4 figures
\\
A novel supersolid phase is predicted for an ensemble of Rydberg atoms in the
dipole-blockade regime, interacting via a repulsive dipolar potential
"softened" at short distances. Using exact numerical techniques, we study the
low temperature phase diagram of this system, and observe an intriguing phase
consisting of a crystal of mesoscopic superfluid droplets. At low temperature,
phase coherence throughout the whole system, and the ensuing bulk
superfluidity, are established through tunnelling of identical particles
between neighbouring droplets.
\\ ( http://arxiv.org/abs/1005.2403 , 477kb)
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The replacements:
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\\
arXiv:0901.4385
replaced with revised version Mon, 10 May 2010 11:00:54 GMT (1014kb)
Title: Metastable Quantum Phase Transitions in a Periodic One-dimensional Bose
Gas: Mean-Field and Bogoliubov Analyses
Authors: R. Kanamoto, L. D. Carr, M. Ueda
Categories: cond-mat.other
Journal-ref: Phys. Rev. A 79, 063616 (2009)
DOI: 10.1103/PhysRevA.79.063616
\\ ( http://arxiv.org/abs/0901.4385 , 1014kb)
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\\
arXiv:0903.0968
replaced with revised version Wed, 12 May 2010 09:15:28 GMT (446kb)
Title: Parametrically excited "Scars" in Bose-Einstein condensates
Authors: Nadav Katz and Oded Agam
Categories: cond-mat.other
\\ ( http://arxiv.org/abs/0903.0968 , 446kb)
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\\
arXiv:0910.2805
replaced with revised version Mon, 10 May 2010 11:05:02 GMT (1126kb)
Title: Metastable quantum phase transitions in a periodic one-dimensional Bose
gas: II. Many-body theory
Authors: R. Kanamoto, L.D. Carr, M. Ueda
Categories: cond-mat.quant-gas
Journal-ref: Phys. Rev. A 81, 023625 (2010); Erratum: Phys. Rev. A 81,
049903(E) (2010)
DOI: 10.1103/PhysRevA.81.023625; 10.1103/PhysRevA.81.049903
\\ ( http://arxiv.org/abs/0910.2805 , 1126kb)
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\\
arXiv:0911.3157
replaced with revised version Tue, 11 May 2010 09:37:26 GMT (1051kb)
Title: Spontaneous population imbalance in two-component Bose and Fermi gases
Authors: Shintaro Takayoshi, Masahiro Sato, Shunsuke Furukawa
Categories: cond-mat.quant-gas cond-mat.str-el
Comments: 7 pages, 5 figures
Journal-ref: Phys. Rev. A 81, 053606 (2010)
DOI: 10.1103/PhysRevA.81.053606
\\ ( http://arxiv.org/abs/0911.3157 , 1051kb)
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\\
arXiv:0912.1239
replaced with revised version Wed, 12 May 2010 14:15:14 GMT (1918kb)
Title: Macroscopic self trapping in BECs: analysis of a dynamical quantum phase
transition
Authors: B. Julia-Diaz, D. Dagnino, M. Lewenstein, J. Martorell, A. Polls
Categories: cond-mat.quant-gas
Comments: Fig 6c,d corrected. 7 pages, 10 eps figures
Journal-ref: Phys. Rev. A 81, 023615 (2010)
DOI: 10.1103/PhysRevA.81.023615
\\ ( http://arxiv.org/abs/0912.1239 , 1918kb)
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\\
arXiv:0912.5022
replaced with revised version Mon, 10 May 2010 13:56:31 GMT (1541kb,D)
Title: Temporal coherence, anomalous moments, and pairing correlations in the
classical-field description of a degenerate Bose gas
Authors: T. M. Wright, P. B. Blakie, and R. J. Ballagh
Categories: cond-mat.quant-gas
Comments: 11 pages, 6 figures. v2: References added. Abstract and introduction
revised
\\ ( http://arxiv.org/abs/0912.5022 , 1541kb)
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\\
arXiv:1001.1004
replaced with revised version Tue, 11 May 2010 19:13:40 GMT (438kb)
Title: RF-field-induced Feshbach resonances
Authors: T. V. Tscherbul, T. Calarco, I. Lesanovsky, R. V. Krems, A. Dalgarno,
J. Schmiedmayer
Categories: physics.atom-ph
Comments: 10 pages, 4 figures; minor typos corrected, journal reference added
Journal-ref: Phys. Rev. A 81, 050701(R) (2010)
DOI: 10.1103/PhysRevA.81.050701
\\ ( http://arxiv.org/abs/1001.1004 , 438kb)
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\\
arXiv:1002.0578
replaced with revised version Fri, 7 May 2010 13:16:18 GMT (272kb)
Title: Generalized Rashba spin-orbit coupling for cold atoms
Authors: Gediminas Juzeliunas, Julius Ruseckas, Jean Dalibard
Categories: cond-mat.quant-gas quant-ph
Comments: 8 figures; corrected typos and figures
Journal-ref: Phys. Rev. A 81, 053403 (2010)
DOI: 10.1103/PhysRevA.81.053403
\\ ( http://arxiv.org/abs/1002.0578 , 272kb)
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\\
arXiv:1002.4652
replaced with revised version Thu, 13 May 2010 18:24:29 GMT (175kb)
Title: Fermi liquid theory of ultra-cold trapped Fermi gases: Implications for
Pseudogap Physics and Other Strongly Correlated Phases
Authors: Chih-Chun Chien and K. Levin
Categories: cond-mat.quant-gas cond-mat.str-el cond-mat.supr-con
Comments: 4 pages, 2 figures, revised version
Report-no: LA-UR 10-00975
\\ ( http://arxiv.org/abs/1002.4652 , 175kb)
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\\
arXiv:1004.4134
replaced with revised version Fri, 7 May 2010 20:20:57 GMT (195kb,D)
Title: Oscillating solitons in a three component BEC
Authors: Piotr Szankowski, Eryk Infeld, Marek Trippenbach
Categories: cond-mat.quant-gas
Comments: 4 pages, 4 figures
\\ ( http://arxiv.org/abs/1004.4134 , 195kb)
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\\
arXiv:1004.4499
replaced with revised version Mon, 10 May 2010 13:54:58 GMT (115kb)
Title: Finite temperature QMC study of the one-dimensional polarized Fermi gas
Authors: M. J. Wolak, V. G. Rousseau, C. Miniatura, B. Gremaud, R. T.
Scalettar, and G. G. Batrouni
Categories: cond-mat.quant-gas
Comments: 10 pages, 13 figures We added a discussion of the behaviour of the
FFLO peak as a function of the attractive interaction strength
\\ ( http://arxiv.org/abs/1004.4499 , 115kb)
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\\
arXiv:1005.0461
replaced with revised version Fri, 7 May 2010 15:05:28 GMT (55kb)
Title: Super-Tonks-Girardeau gas of spin-1/2 interacting fermions
Authors: Liming Guan and Shu Chen
Categories: cond-mat.quant-gas
Comments: 4 pages, 4 figures
\\ ( http://arxiv.org/abs/1005.0461 , 55kb)
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Till next time,
Matt.
--
=========================================================================
Dr M. J. Davis, Associate Professor in Physics
School of Mathematics and Physics, ph : +61 7 334 69824
The University of Queensland, fax : +61 7 336 51242
Brisbane, QLD 4072, mdavis_at_physics.uq.edu.au
Australia. 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 Thu Jun 10 2010 - 16:22:09 EST
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