The following message was sent to the matts_arxiv list by Matthew Davis <mdavis_at_physics.uq.edu.au>
Hello again,
Thankfully the teaching semester is now over and this should give me a chance to
get you back up to date. For this week (which was now three weeks ago!) there
were 25 new preprints and 14 replacements:
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arXiv:0709.4554
Date: Fri, 28 Sep 2007 09:00:07 GMT (28kb)
Title: Feshbach resonances in mixtures of ultracold $^6$Li and $^{87}$Rb gases
Authors: B. Deh, C. Marzok, C. Zimmermann and Ph. W. Courteille
Categories: cond-mat.other cond-mat.soft
\\
We report on the observation of several Feshbach resonances in collisions
between ultracold $^6$Li and $^{87}$Rb atoms in their respective hyperfine
ground states $|F,m_F>=|1/2,1/2>$ and $|1,1>$. The resonances show up as trap
losses for the $^6$Li cloud induced by inelastic Li-Rb-Rb three-body
collisions. The magnetic field values where they occur represent important
benchmarks for an accurate determination of the interspecies interaction
potentials. A broad Feshbach resonance located at 1066.92 G opens interesting
prospects for the creation of ultracold heteronuclear molecules. We furthermore
observe a strong enhancement of the narrow p-wave Feshbach resonance in
collisions of $^6$Li atoms at 158.55 G in the presence of a dense $^{87}$Rb
cloud. The effect of the $^{87}$Rb cloud is to introduce Li-Li-Rb three-body
collisions occurring at a higher rate than Li-Li-Li collisions.
\\ ( http://arxiv.org/abs/0709.4554 , 28kb)
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arXiv:0709.4596
Date: Fri, 28 Sep 2007 12:28:09 GMT (177kb)
Title: Ground state fidelity from tensor network representations
Authors: Huan-Qiang Zhou, Roman Orus and Guifre Vidal
Categories: cond-mat.stat-mech cond-mat.str-el
Comments: 5 pages, 2 figures
\\
For any $D$-dimensional quantum lattice system, the fidelity between two
ground state many-body wave functions is mapped onto the partition function of
a $D$-dimensional classical statistical vertex lattice model with the same
lattice geometry. The fidelity per lattice site, analogous to the free energy
per site, is well-defined in the thermodynamic limit and can be used to
characterize the phase diagram of the model. We explain how to compute the
fidelity per site in the context of tensor network algorithms, and demonstrate
the approach by analyzing the two-dimensional quantum Ising model with
transverse and parallel magnetic fields.
\\ ( http://arxiv.org/abs/0709.4596 , 177kb)
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arXiv:0709.4609
Date: Fri, 28 Sep 2007 13:20:37 GMT (38kb)
Title: Super-Tonks-Girardeau regime in trapped one-dimensional dipolar gases
Authors: G. E. Astrakharchik and Yu. E. Lozovik
Categories: cond-mat.other
\\
Possible signatures of a super-Tonks-Girardeau gas in bosonic systems of
trapped quasi-one-dimensional dipoles are discussed at zero temperature. We
provide estimation of the frequency of the lowest compressional mode and
compare it to analytical results derived using harmonic approach in the high
density regime. We construct an exact mapping of the ground-state wave function
of one-dimensional dipolar system of bosons, fermions and Bose-Fermi mixture
and conclude that local properties and energy are the same at zero temperature.
A question of to which extent the dipolar potential can be treated long- or
short- range is discussed.
\\ ( http://arxiv.org/abs/0709.4609 , 38kb)
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arXiv:0709.4620
Date: Fri, 28 Sep 2007 14:28:38 GMT (244kb)
Title: Mott transition in one dimension: Benchmarking dynamical cluster
approaches
Authors: Matthias Balzer, Werner Hanke and Michael Potthoff
Categories: cond-mat.str-el cond-mat.supr-con
Comments: 19 pages, 19 figures
\\
The variational cluster approach (VCA) is applied to the one-dimensional
Hubbard model at zero temperature using clusters (chains) of up to ten sites
with full diagonalization and the Lanczos method as cluster solver. Within the
framework of the self-energy-functional theory (SFT), different cluster
reference systems with and without bath degrees of freedom, in different
topologies and with different sets of variational parameters are considered.
Static and one-particle dynamical quantities are calculated for half-filling as
a function of U as well as for fixed U as a function of the chemical potential
to study the interaction- and filling-dependent metal-insulator (Mott)
transition. The recently developed Q-matrix technique is used to compute the
SFT grand potential. For benchmarking purposes we compare the VCA results with
exact results available from the Bethe ansatz, with essentially exact dynamical
DMRG data, with (cellular) dynamical mean-field theory and full diagonalization
of isolated Hubbard chains. Several issues are discussed including convergence
of the results with cluster size, the ability of cluster approaches to access
the critical regime of the Mott transition, efficiency in the optimization of
correlated-site vs. bath-site parameters and of multi-dimensional parameter
optimization. We also study the role of bath sites for the description of
excitation properties and as charge reservoirs for the description of filling
dependencies. The VCA turns out to be a computationally cheap method which is
competitive with established cluster approaches.
\\ ( http://arxiv.org/abs/0709.4620 , 244kb)
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arXiv:0709.4675
Date: Fri, 28 Sep 2007 19:13:10 GMT (46kb)
Title: Measurement of the ac Stark shift with a guided matter-wave
interferometer
Authors: B. Deissler, K. J. Hughes, J. H. T. Burke, and C. A. Sackett
Categories: physics.atom-ph
Comments: 5 pages, three figures
\\
We demonstrate the effectiveness of a guided-wave Bose-Einstein condensate
interferometer for practical measurements. Taking advantage of the large arm
separations obtainable in our interferometer, the energy levels of the 87Rb
atoms in one arm of the interferometer are shifted by a calibrated laser beam.
The resulting phase shifts are used to determine the ac polarizability at a
range of frequencies near and at the atomic resonance. The measured values are
in good agreement with theoretical expectations. However, we observe a
broadening of the transition near the resonance, an indication of collective
light scattering effects. This nonlinearity may prove useful for the production
and control of squeezed quantum states.
\\ ( http://arxiv.org/abs/0709.4675 , 46kb)
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arXiv:0709.4577 (*cross-listing*)
Date: Fri, 28 Sep 2007 11:15:48 GMT (103kb)
Title: Sub-Kelvin Cooling of a Macroscopic Oscillator and femto-Newton Force
Measurement
Authors: F. Mueller, S. Heugel and L. J. Wang
Categories: physics.ins-det physics.optics
Comments: 5 pages, 5 figures
\\
Measuring very small forces, particularly those of a gravitational nature,
has always been of great interest, as fundamental tests of our understanding of
the physical laws. Ultra-long period mechanical oscillators, typically used in
such measurements, will have kT/2 of thermal energy associated with each degree
of freedom, owing to the equal-partition of energy. Moreover, additional
seismic fluctuations in the low frequency band can raise this equivalent
temperature significantly to 10^5 K. Recently, various methods using
opto-mechanical forces have been reported to decrease this thermal energy for
MHz, micro-cantilever oscillators, effectively cooling them. Here we show the
direct, dynamical cooling of a gram-size, macroscopic oscillator to 300 mK in
equivalent temperature - noise reduction by a factor of 10^6. By precisely
measuring the torsional oscillator's position, we dynamically provide an
external 'viscous' damping force. Such an added, dissipative force is
essentially free of noise, resulting in rapid cooling of the oscillator.
Additionally, we observe the time-dependent cooling process, at various cooling
force parameters. This parameter dependence agrees well with a simple physical
model which we provide. We further show that the device is sensitive to forces
as small as <100 fN - a force only a few percent of that typically exerted by a
single biological molecule or that observed in a typical gravity experiment. We
also demonstrate the dynamic control of the oscillator's natural frequency,
over a span of nearly two decades. The method may find important applications
in precision measurements of very weak forces.
\\ ( http://arxiv.org/abs/0709.4577 , 103kb)
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arXiv:0710.0023
Date: Fri, 28 Sep 2007 22:30:59 GMT (97kb)
Title: Pairing with Unconventional Symmetry around BCS-BEC Crossover: Fermionic
Atoms in 2D Optical Lattices to Correlated Electron Systems
Authors: Dusan Volcko and Khandker F. Quader
Categories: cond-mat.supr-con cond-mat.other
Comments: 5 pages, 4 figures
\\
We study superfluid properties of fermions on a 2D lattice using a
finite-range pairing interaction derivable from an extended Hubbard model. We
obtain signatures of unconventional pair-symmetry states, $d_{x^2-y^2}$ and
extended-s ($s^*$), in the BCS-BEC crossover region. The fermion momentum
distribution function, $v_k^2$, the ratio of the Bogoliubov coefficients,
$v_k/u_k$, and the Fourier transform of $v_k^2$ are among the properties that
are strikingly different for d- and $s^*$ symmetries in the crossover region.
Fermionic atoms in 2D optical lattices may provide a way to observe these
signatures. We discuss possible experimental ramifications of our results.
\\ ( http://arxiv.org/abs/0710.0023 , 97kb)
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arXiv:0710.0023
Date: Fri, 28 Sep 2007 22:30:59 GMT (97kb)
Title: Pairing with Unconventional Symmetry around BCS-BEC Crossover: Fermionic
Atoms in 2D Optical Lattices to Correlated Electron Systems
Authors: Dusan Volcko and Khandker F. Quader
Categories: cond-mat.supr-con cond-mat.other
Comments: 5 pages, 4 figures
\\
We study superfluid properties of fermions on a 2D lattice using a
finite-range pairing interaction derivable from an extended Hubbard model. We
obtain signatures of unconventional pair-symmetry states, $d_{x^2-y^2}$ and
extended-s ($s^*$), in the BCS-BEC crossover region. The fermion momentum
distribution function, $v_k^2$, the ratio of the Bogoliubov coefficients,
$v_k/u_k$, and the Fourier transform of $v_k^2$ are among the properties that
are strikingly different for d- and $s^*$ symmetries in the crossover region.
Fermionic atoms in 2D optical lattices may provide a way to observe these
signatures. We discuss possible experimental ramifications of our results.
\\ ( http://arxiv.org/abs/0710.0023 , 97kb)
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arXiv:0710.0045
Date: Sat, 29 Sep 2007 08:02:03 GMT (829kb)
Title: Quantum Entangled Dark Solitons Formed by Ultracold Atoms in Optical
Lattices
Authors: R. V. Mishmash, L. D. Carr
Categories: cond-mat.mes-hall
Comments: 4 pages, 4 figures
\\
Inspired by experiments on Bose-Einstein condensates in optical lattices, we
study the quantum evolution of dark soliton mean-field initial conditions in
the context of the Bose-Hubbard Hamiltonian. An extensive set of quantum
measures is utilized in our analysis, including von Neumann and generalized
quantum entropies, quantum depletion, and number fluctuations. We find that
quantum effects cause the soliton to fill in. Moreover, soliton-soliton
collisions become inelastic, in strong contrast to the predictions of
mean-field theory. These features show that the lifetime and collision
properties of dark solitons in optical lattices provide clear signals of
quantum effects.
\\ ( http://arxiv.org/abs/0710.0045 , 829kb)
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arXiv:0710.0208
Date: Mon, 1 Oct 2007 06:21:07 GMT (256kb)
Title: Hanbury Brown and Twiss correlations in atoms scattered from colliding
condensates
Authors: Klaus Molmer, A. Perrin, V. Krachmalnicoff, V. Leung, D. Boiron, A.
Aspect, C.I. Westbrook
Categories: cond-mat.other
Comments: 7 pages, 3 figures
\\
Low energy elastic scattering between clouds of Bose condensed atoms leads to
the well known s-wave halo with atoms emerging in all directions from the
collision zone. In this paper we discuss the emergence of Hanbury Brown and
Twiss coincidences between atoms scattered in nearly parallel directions. We
develop a simple model that explains the observations in terms of an
interference involving two pairs of atoms each associated with the elementary s
wave scattering process.
\\ ( http://arxiv.org/abs/0710.0208 , 256kb)
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arXiv:0710.0348
Date: Mon, 1 Oct 2007 18:00:27 GMT (57kb)
Title: Finite-temperature Bell test for quasiparticle entanglement in the Fermi
sea
Authors: W.-R. Hannes, M. Titov
Categories: cond-mat.mes-hall
Comments: 4 pages, 3 figures
\\
We demonstrate that the Bell test cannot be realized at finite temperatures
in the vast majority of electronic setups proposed previously for quantum
entanglement generation. This fundamental difficulty is shown to originate in a
finite probability of quasiparticle emission from Fermi-sea detectors. In order
to overcome the feedback problem we suggest a detection strategy, which takes
advantage of a resonant coupling and of an additional detector cooling. Unlike
other proposals the designed Bell test provides a possibility to determine the
critical temperature for entanglement production in the solid state.
\\ ( http://arxiv.org/abs/0710.0348 , 57kb)
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arXiv:0710.0353
Date: Mon, 1 Oct 2007 19:58:22 GMT (25kb)
Title: Trap-Imbalanced Fermion Mixtures
Authors: M. Iskin and C. J. Williams
Categories: cond-mat.supr-con cond-mat.other
Comments: 4 pages and 3 figures
\\
We analyze the ground state phases of two-component ($\uparrow$ and
$\downarrow$) population- and mass-balanced ($N_\uparrow = N_\downarrow$ and
$m_\uparrow = m_\downarrow$) but trap-imbalanced ($\omega_\uparrow \ne
\omega_\downarrow$) fermion mixtures as a function of interaction strength from
the weak attraction (BCS) to the strong attraction (BEC) limit. In the BCS
limit, we find that the unpolarized superfluid (UPS) fermions are surrounded by
unpolarized normal (UPN) fermions, and that they exist only away from the
central core of the trapping potentials where the normal fermions are partially
polarized. As the interactions increase towards unitarity, we find that the
central core first becomes a UPN, and then transitions to a UPS. Further
increasing the interactions, we find that the central UPS region expands, but
the inner superfluid and normal regions shrink towards the edges until the
entire mixture becomes a UPS in the BEC limit.
\\ ( http://arxiv.org/abs/0710.0353 , 25kb)
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arXiv:0710.0110
Date: Sun, 30 Sep 2007 06:48:05 GMT (122kb)
Title: Storage of spin squeezing in a two-component Bose-Einstein condensate
Authors: Guang-Ri Jin and Sang Wook Kim
Categories: quant-ph
Comments: 10 pages, 5 figures. This version is slightly different from the one
published in Phys. Rev. Lett
\\
Efficient control of spin squeezing in a two-component Bose-Einstein
Condensate is studied by rapidly turning-off the external field at a time that
maximal spin squeezing appears. We show that strong reduction of spin
fluctuation can be maintained in a nearly fixed direction for a long time. We
explain the underlying physics unambiguously, and present analytical
expressions of the maximal-squeezing time.
\\ ( http://arxiv.org/abs/0710.0110 , 122kb)
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arXiv:0710.0112
Date: Sun, 30 Sep 2007 07:24:28 GMT (63kb)
Title: Improvement of conversion efficiency of atom-molecule Bose-Einstein
condensate
Authors: Guang-Ri Jin and Sang Wook Kim
Categories: quant-ph
Comments: 4 pages, 4 figures. To be appeared in J. Korean Phys. Society (JKPS)
\\
We investigate the stimulated Raman adiabatic passage in two-color
photoassociation for a atom-molecule Bose-Einstein condensate. By applying two
time-varying Guassian laser pulses that fulfill generalized two-photon
resonance condition, we obtain highly efficient atom-molecule conversion. The
efficiency depends on the free-bound detuning and the delay time between the
two pulses. By adjusting the parameters optimally, we achieve 92% conversion
efficiency.
\\ ( http://arxiv.org/abs/0710.0112 , 63kb)
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arXiv:0710.0278
Date: Mon, 1 Oct 2007 12:46:41 GMT (180kb)
Title: Demonstration of fractional statistics of anyons in the Kitaev
lattice-spin model
Authors: Chao-Yang Lu, Wei-Bo Gao, Otfried G\"uhne, Xiao-Qi Zhou, Zeng-Bing
Chen, Jian-Wei Pan
Categories: quant-ph
Comments: 13 pages, double space, 4 figures. Comments will be appreciated
\\
In two dimensions, the laws of physics permit the existence of exotic
quasiparticles--anyons--that do not fit into the usual categories of fermions
and bosons, but obey a new form of fractional statistics. They have been
predicted to live as excitations in fractional quantum Hall systems. Quantum
states with anyonic excitations can also be artificially designed in model
systems that have highly nontrivial ground states with topological order. A
prominent example is the Kitaev lattice-spin models, which opened the avenue of
fault-tolerant topological quantum computing. Demonstration of the anyonic
fractional statistics is not only of fundamental interest, but also a
cornerstone of the emerging field of topological quantum computation. While
there is fast progress in the theoretical proposals, an unambiguous observation
of fractional statistics associated with anyon braiding still remained a real
experimental challenge. On the one hand, although some signatures have been
observed in the fractional quantum Hall systems, these experiments did not
resolve individual anyons. On the other hand, controlling cold atomic or
moleculargases in optical lattices to realize the spin models is still beyond
the current experimental capabilities. Here we report the demonstration of the
fractional statistics of anyons by simulation of the Kitaev lattice-spin model
on a six-photon graph state. Our method is to first create the ground state and
excited state of the model Hamiltonian, and then implement the braiding and
fusion operations by single-qubit rotations. Our experimental platform could
also be seen as a quantum simulator, with good controllability and purity,
which may be promising for future studies of quantum many-body physics.
\\ ( http://arxiv.org/abs/0710.0278 , 180kb)
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arXiv:0710.0285
Date: Mon, 1 Oct 2007 18:59:42 GMT (483kb)
Title: Quantum-limited metrology with product states
Authors: Sergio Boixo, Animesh Datta, Steven T. Flammia, Anil Shaji, Emilio
Bagan, and Carlton M. Caves
Categories: quant-ph
Comments: 15 pages, 6 figures
\\
We study the performance of initial product states of n-body systems in
generalized quantum metrology protocols that involve estimating an unknown
coupling constant in a nonlinear k-body (k << n) Hamiltonian. We obtain the
theoretical lower bound on the uncertainty in the estimate of the parameter.
For arbitrary initial states, the lower bound scales as 1/n^k, and for initial
product states, it scales as 1/n^(k-1/2). We show that the latter scaling can
be achieved using simple, separable measurements. We analyze in detail the case
of a quadratic Hamiltonian (k = 2), implementable with Bose-Einstein
condensates. We formulate a simple model, based on the evolution of
angular-momentum coherent states, which explains the O(n^(-3/2)) scaling for k
= 2; the model shows that the entanglement generated by the quadratic
Hamiltonian does not play a role in the enhanced sensitivity scaling. We show
that phase decoherence does not affect the O(n^(-3/2)) sensitivity scaling for
initial product states.
\\ ( http://arxiv.org/abs/0710.0285 , 483kb)
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arXiv:0710.0086
Date: Sat, 29 Sep 2007 19:04:24 GMT (273kb)
Title: An Optical Lattice Clock with Spin-polarized 87Sr Atoms
Authors: Xavier Baillard (SYRTE), Mathilde Fouch\'e (SYRTE), Rodolphe Le Targat
(SYRTE), Philip G. Westergaard (SYRTE), Arnaud Lecallier (SYRTE),
Fr\'ed\'eric Chapelet (SYRTE), Michel Abgrall (SYRTE), Giovanni D. Rovera
(SYRTE), Philippe Laurent (SYRTE), Peter Rosenbusch (SYRTE), S\'ebastien Bize
(SYRTE), Giorgio Santarelli (SYRTE), Andr\'e Clairon (SYRTE), Pierre Lemonde
(SYRTE), Gesine Grosche (PTB), Burghard Lipphardt (PTB), Harald Schnatz (PTB)
Categories: physics.atom-ph
Proxy: ccsd hal-00175653
\\
We present a new evaluation of an 87Sr optical lattice clock using spin
polarized atoms. The frequency of the 1S0-3P0 clock transition is found to be
429 228 004 229 873.6 Hz with a fractional accuracy of 2.6 10^{-15}, a value
that is comparable to the frequency difference between the various primary
standards throughout the world. This measurement is in excellent agreement with
a previous one of similar accuracy.
\\ ( http://arxiv.org/abs/0710.0086 , 273kb)
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arXiv:0710.0522
Date: Tue, 2 Oct 2007 13:19:42 GMT (712kb)
Title: Localisation and Delocalisation of Ultracold Bosonic Atoms in Finite
Optical Lattices
Authors: Dirk-S\"oren L\"uhmann, Kai Bongs, Klaus Sengstock, Daniela Pfannkuche
Categories: cond-mat.other
Comments: 8 pages, 10 figures
\\
We study bosonic atoms in small optical lattices by exact diagonalisation and
observe a striking similarity to the superfluid to Mott insulator transition in
macroscopic systems. The momentum distribution, the formation of an energy gap
and the pair correlation function show only a weak size dependence. For
non-commensurate filling we reveal a mixture of localised and delocalised
particles, which is sensitive to lattice imperfections. Breaking the lattice
symmetry causes a Bose glass like behaviour. We discuss the nature of excited
states and orbital effects by using a multi-band diagonalisation technique.
\\ ( http://arxiv.org/abs/0710.0522 , 712kb)
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arXiv:0710.0607
Date: Tue, 2 Oct 2007 19:28:14 GMT (660kb)
Title: Localized modes of binary mixtures of Bose-Einstein condensates in
nonlinear optical lattices
Authors: F. Kh. Abdullaev, A. Gammal, M. Salerno, Lauro Tomio
Categories: cond-mat.other
Comments: 13 pages, 14 figures
\\
The properties of the localized states of a two component Bose-Einstein
condensate confined in a nonlinear periodic potential [nonlinear optical
lattice] are investigated. We reveal the existence of new types of solitons and
study their stability by means of analytical and numerical approaches. The
symmetry properties of the localized states with respect to the NOL are also
investigated. We show that nonlinear optical lattices allow the existence of
bright soliton modes with equal symmetry in both components, bright localized
modes of mixed symmetry type, as well as, dark-bright bound states and bright
modes on periodic backgrounds. In spite of the quasi 1D nature of the problem,
the fundamental symmetric localized modes undergo a delocalizing transition
when the strength of the nonlinear optical lattice is varied. This transition
is associated with the existence of an unstable solution, which exhibits a
shrinking (decaying) behavior for slightly overcritical (undercritical)
variations in the number of atoms.
\\ ( http://arxiv.org/abs/0710.0607 , 660kb)
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arXiv:0710.0396
Date: Mon, 1 Oct 2007 22:11:43 GMT (156kb)
Title: Higher-order splitting algorithms for solving the nonlinear
Schr\"odinger equation and their instabilities
Authors: Siu A. Chin
Categories: physics.comp-ph physics.atom-ph
Comments: 10 pages, 8 figures, submitted to Phys. Rev. E
\\
Since the kinetic and the potential energy term of the real time nonlinear
Schr\"odinger equation can each be solved exactly, the entire equation can be
solved to any order via splitting algorithms. We verified the fourth-order
convergence of some well known algorithms by solving the Gross-Pitaevskii
equation numerically. All such splitting algorithms suffer from a latent
numerical instability even when the total energy is very well conserved. A
detail error analysis reveals that the noise, or elementary excitations of the
nonlinear Schr\"odinger, obeys the Bogoliubov spectrum and the instability is
due to the exponential growth of high wave number noises caused by the
splitting process. For a continuum wave function, this instability is
unavoidable no matter how small the time step. For a discrete wave function,
the instability can be avoided only for $\dt k_{max}^2{<\atop\sim}2 \pi$, where
$k_{max}=\pi/\Delta x$.
\\ ( http://arxiv.org/abs/0710.0396 , 156kb)
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arXiv:0710.0692
Date: Wed, 3 Oct 2007 02:14:34 GMT (824kb)
Title: Entanglement renormalization in fermionic systems
Authors: G. Evenbly, G. Vidal
Categories: quant-ph
Comments: 5 pages, 4 figures
\\
We demonstrate, in the context of quadratic fermion lattice models in one and
two spatial dimensions, the potential of entanglement renormalization (ER) to
define a proper real-space renormalization group transformation. Our results
show, for the first time, the validity of the multi-scale entanglement
renormalization ansatz (MERA) to describe ground states in two dimensions, even
at a quantum critical point. They also unveil a connection between the
performance of ER and the logarithmic violations of the boundary law for
entanglement in systems with a one-dimensional Fermi surface. ER is recast in
the language of creation/annihilation operators and correlation matrices.
\\ ( http://arxiv.org/abs/0710.0692 , 824kb)
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arXiv:0710.0766
Date: Wed, 3 Oct 2007 11:52:30 GMT (236kb,D)
Title: Atomic diffraction in counter-propagating Gaussian pulses of laser light
Authors: Tapio P. Simula, Atom Muradyan and Klaus Molmer
Categories: quant-ph
Comments: 6 pages, 5 figures
\\
We present an analysis of atomic diffraction due to the interaction of an
atomic beam with a pair of Gaussian light pulses. We derive a simple analytical
expression for the populations in different diffraction orders. The validity of
the obtained solution extends beyond the Raman-Nath regime, where the kinetic
energy associated with different diffraction peaks is neglected, into the
so-called channeling regime where accurate analytical expressions have not
previously been available for the diffraction. Comparison with experimental
results and exact numerical solutions demonstrate the validity of our
analytical formula.
\\ ( http://arxiv.org/abs/0710.0766 , 236kb)
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arXiv:0710.0733
Date: Wed, 3 Oct 2007 08:31:06 GMT (15kb)
Title: Total control over ultracold interactions via electric and magnetic
fields
Authors: Bout Marcelis, Boudewijn Verhaar, and Servaas Kokkelmans
Categories: physics.atom-ph
Comments: 4 pages, 3 figures
\\
The scattering length is commonly used to characterize the strength of
ultracold atomic interactions, since it is the leading parameter in the
low-energy expansion of the scattering phase shift. Its value can be modified
via a magnetic field, by using a Feshbach resonance. However, the effective
range term, which is the second parameter in the phase shift expansion,
determines the width of the resonance and gives rise to important properties of
ultracold gases. Independent control over this parameter is not possible by
using a magnetic field only. We demonstrate that a combination of magnetic and
electric fields can be used to get independent control over both parameters,
which leads to full control over elastic ultracold interactions.
\\ ( http://arxiv.org/abs/0710.0733 , 15kb)
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arXiv:0710.0927
Date: Thu, 4 Oct 2007 06:46:57 GMT (165kb)
Title: Optical pumping via incoherent Raman transitions
Authors: A. D. Boozer, R. Miller, T. E. Northup, A. Boca, and H. J. Kimble
Categories: quant-ph
Comments: 8 pages, 4 figures
\\
A new optical pumping scheme is presented that uses incoherent Raman
transitions to prepare a trapped Cesium atom in a specific Zeeman state within
the 6S_{1/2}, F=3 hyperfine manifold. An important advantage of this scheme
over existing optical pumping schemes is that the atom can be prepared in any
of the F=3 Zeeman states. We demonstrate the scheme in the context of cavity
quantum electrodynamics, but the technique is equally applicable to a wide
variety of atomic systems with hyperfine ground-state structure.
\\ ( http://arxiv.org/abs/0710.0927 , 165kb)
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arXiv:0710.1081
Date: Thu, 4 Oct 2007 19:52:31 GMT (92kb)
Title: Confinement effects in a guided-wave interferometer with
millimeter-scale arm separation
Authors: J. H. T. Burke, B. Deissler, K. J. Hughes and C. A. Sackett
Categories: physics.atom-ph
Comments: 14 pages, 6 figures
\\
Guided-wave atom interferometers measure interference effects using atoms
held in a confining potential. In one common implementation, the confinement is
primarily two-dimensional, and the atoms move along the nearly free dimension
under the influence of an off-resonant standing wave laser beam. In this
configuration, residual confinement along the nominally free axis can introduce
a phase gradient to the atoms that limits the arm separation of the
interferometer. We experimentally investigate this effect in detail, and show
that it can be alleviated by having the atoms undergo a more symmetric motion
in the guide. This can be achieved by either using additional laser pulses or
by allowing the atoms to freely oscillate in the potential. Using these
techniques, we demonstrate interferometer measurement times up to 72 ms and arm
separations up to 0.42 mm with a well controlled phase, or times of 0.91 s and
separations of 1.7 mm with an uncontrolled phase.
\\ ( http://arxiv.org/abs/0710.1081 , 92kb)
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The replacements:
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arXiv:0709.4123
replaced with revised version Fri, 28 Sep 2007 14:00:25 GMT (272kb)
Title: Statistics of the polariton condensate
Authors: Paolo Schwendimann and Antonio Quattropani
Categories: cond-mat.other cond-mat.supr-con
Comments: 35 pages, 4 figures
\\ ( http://arxiv.org/abs/0709.4123 , 272kb)
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arXiv:0705.1258
replaced with revised version Fri, 28 Sep 2007 19:39:39 GMT (137kb)
Title: A method of state-selective transfer of atoms between microtraps based
on the Franck-Condon Principle
Authors: A. B. Deb, G. Smirne, R. M. Godun, C. J. Foot
Categories: physics.atom-ph
Comments: 8 pages, 6 figures. Accepted for publication Journal of Physics B
(Atomic, molecular and optical physics)
\\ ( http://arxiv.org/abs/0705.1258 , 137kb)
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arXiv:cond-mat/0702505
replaced with revised version Fri, 28 Sep 2007 22:20:41 GMT (436kb)
Title: Fermi-Luttinger liquid: Spectral function of interacting one-dimensional
fermions
Authors: M. Khodas, M. Pustilnik, A. Kamenev, L.I. Glazman
Categories: cond-mat.mes-hall
\\ ( http://arxiv.org/abs/cond-mat/0702505 , 436kb)
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arXiv:0704.3047
replaced with revised version Mon, 1 Oct 2007 12:56:36 GMT (949kb)
Title: Observation of atom pairs in spontaneous four wave mixing of two
colliding Bose-Einstein Condensates
Authors: A. Perrin (LCFIO), H. Chang (LCFIO), V. Krachmalnicoff (LCFIO), M.
Schellekens (LCFIO), D. Boiron (LCFIO), A. Aspect (LCFIO), C. I. Westbrook
(LCFIO)
Categories: quant-ph
Proxy: ccsd hal-00142991
\\ ( http://arxiv.org/abs/0704.3047 , 949kb)
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arXiv:0704.0291 (*cross-listing*)
replaced with revised version Tue, 2 Oct 2007 01:38:13 GMT (324kb)
Title: Approaching the Heisenberg limit in an atom laser
Authors: M. Jeppesen, J. Dugu\'e, G. R. Dennis, M. T. Johnsson, C. Figl, N. P.
Robins and J. D. Close
Categories: physics.atom-ph cond-mat.other
Comments: Corrected analysis, added figure
\\ ( http://arxiv.org/abs/0704.0291 , 324kb)
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arXiv:quant-ph/0701167
replaced with revised version Tue, 2 Oct 2007 12:13:46 GMT (636kb)
Title: Cold Atom Physics Using Ultra-Thin Optical Fibers: Light-Induced Dipole
Forces and Surface Interactions
Authors: G. Sagu\'e, E. Vetsch, W. Alt, D. Meschede and A. Rauschenbeutel
Categories: quant-ph
Comments: 4 pages, 4 figures. Accepted for publication in PRL
\\ ( http://arxiv.org/abs/quant-ph/0701167 , 636kb)
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arXiv:physics/0701272
replaced with revised version Tue, 2 Oct 2007 17:44:06 GMT (578kb)
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: Substantially revised to incorporate referee suggestions. 10 pages, 5
figures
\\ ( http://arxiv.org/abs/physics/0701272 , 578kb)
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arXiv:0708.2257
replaced with revised version Wed, 3 Oct 2007 17:25:15 GMT (412kb)
Title: Dynamics of Atom-Field Entanglement from Exact Solutions: Towards Strong
Coupling and Non-Markovian Regimes
Authors: Nick Cummings, B. L. Hu
Categories: quant-ph
Comments: 12 pages, 5 figures; minor changes in grammar, wording, and
formatting. One unnecessary figure removed. Figure number revised (no longer
counts subfigures separately)
\\ ( http://arxiv.org/abs/0708.2257 , 412kb)
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arXiv:0709.2132
replaced with revised version Wed, 3 Oct 2007 15:28:37 GMT (177kb)
Title: Dynamics of vortices in weakly interacting Bose-Einstein condensates
Authors: Alexander Klein, Dieter Jaksch, Yanzhi Zhang and Weizhu Bao
Categories: quant-ph
Comments: 8 pages, 7 figures, one reference updated, typos corrected
Journal-ref: Phys. Rev. A 76, 043602 (2007)
DOI: 10.1103/PhysRevA.76.043602
\\ ( http://arxiv.org/abs/0709.2132 , 177kb)
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arXiv:0706.2855
replaced with revised version Thu, 4 Oct 2007 08:27:10 GMT (22kb)
Title: Crystalline phase of strongly interacting Fermi mixtures
Authors: D. S. Petrov, G. E. Astrakharchik, D. J. Papoular, C. Salomon, G. V.
Shlyapnikov
Categories: cond-mat.stat-mech
Comments: 4 pages, 1 color figure, published version
Report-no: NSF-KITP-07-132
Journal-ref: Phys. Rev. Lett. 99, 130407 (2007)
DOI: 10.1103/PhysRevLett.99.130407
\\ ( http://arxiv.org/abs/0706.2855 , 22kb)
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arXiv:cond-mat/0702569 (*cross-listing*)
Date: Sat, 24 Feb 2007 14:20:32 GMT (20kb)
Date (revised v2): Mon, 14 May 2007 09:39:55 GMT (20kb)
Date (revised v3): Thu, 2 Aug 2007 04:04:31 GMT (23kb)
Title: Quantum rearrangement and self-consistent BCS-BEC crossover
thermodynamics
Authors: Ji-sheng Chen, Chuan-ming Cheng, Jia-rong Li, Yan-ping Wang
Categories: cond-mat.stat-mech hep-ph nucl-th quant-ph
Comments: published version revised according to comments; a few typos fixed
and references updated
Journal-ref: Phys. Rev. A 76, 033617 (2007)
DOI: 10.1103/PhysRevA.76.033617
\\
Based on previous works, analytical calculational procedures for dealing with
the strongly interacting fermions ground state are further developed through a
medium dependent potential in terms of the Bethe-Peierls contact interaction
model. The methods are exact in the unitary limit regime and they lead to the
self-consistent equations analogous to the Hartree ones. The single particle
energy spectrum rearrangement effects on the thermodynamics due to the
Hugenholtz-van Hove theorem constraint are addressed. These effects lead to an
additional instantaneous correlation potential contribution to the system
physical chemical potential and pressure, i.e., equation of state, which
enforces the classical thermodynamic consistency. The Dyson-Schwinger equations
represent implicitly the various Bethe-Goldstone expansion ones. In a
thermodynamically self-consistent way, the universal dimensionless factor is
analytically calculated to be $\xi=\049$, which defines the ratio of the
unitary fermions energy density to that of the ideal non-interacting ones at
T=0.
\\ ( http://arxiv.org/abs/cond-mat/0702569 , 23kb)
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arXiv:quant-ph/0703199
replaced with revised version Thu, 4 Oct 2007 09:43:10 GMT (706kb)
Title: Bose-Einstein condensate coupled to a nanomechanical resonator on an
atom chip
Authors: Philipp Treutlein, David Hunger, Stephan Camerer, Theodor W. H\"ansch,
and Jakob Reichel
Categories: quant-ph
Comments: published version (5 pages, 3 figures)
Journal-ref: Phys. Rev. Lett. 99, 140403 (2007)
\\ ( http://arxiv.org/abs/quant-ph/0703199 , 706kb)
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arXiv:0708.0253
replaced with revised version Thu, 4 Oct 2007 00:42:59 GMT (114kb)
Title: Many-body quantum coherence and interaction blockade in Josephson-linked
Bose-Einstein condensates
Authors: Chaohong Lee, Libin Fu, Yuri S. Kivshar
Categories: quant-ph
Comments: 6 pages, 6 figures
\\ ( http://arxiv.org/abs/0708.0253 , 114kb)
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arXiv:0707.2015
replaced with revised version Thu, 4 Oct 2007 18:04:36 GMT (152kb)
Title: Trapping of ultracold polar molecules with a Thin Wire Electrostatic
Trap
Authors: J. Kleinert, C. Haimberger, P. J. Zabawa, and N. P. Bigelow
Categories: physics.atom-ph
Comments: 4 pages, 3 figures
DOI: 10.1103/PhysRevLett.99.143002
\\ ( http://arxiv.org/abs/0707.2015 , 152kb)
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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/ ========================================================================= Legal stuff: Unless stated otherwise, this e-mail represents only the views of the sender and not the views of the University of Queensland =========================================================================Received on Mon Oct 29 2007 - 22:41:14 EST
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