From: Matthew Davis <mdavis_at_physics.uq.edu.au>

Date: Fri, 10 Jul 2009 14:41:59 +1000

Date: Fri, 10 Jul 2009 14:41:59 +1000

Dear subscribers,

This week we thank Jacopo Sabbatini. There are 24 new preprints and 5 replacements:

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arXiv:0906.1110

Date: Fri, 5 Jun 2009 12:37:14 GMT (551kb,D)

Title: Dynamical creation of a supersolid in asymmetric mixtures of bosons

Authors: Tassilo Keilmann, J. Ignacio Cirac and Tommaso Roscilde

Categories: cond-mat.quant-gas

Comments: Accepted at Phys. Rev. Lett

\\

We propose a scheme to dynamically create a supersolid state in an optical

lattice, using an attractive mixture of mass-imbalanced bosons. Starting from a

"molecular" quantum crystal, supersolidity is induced dynamically as an

out-of-equilibrium state. When neighboring molecular wavefunctions overlap,

both bosonic species simultaneously exhibit quasi-condensation and long-range

solid order, which is stabilized by their mass imbalance. Supersolidity appears

in a perfect one-dimensional crystal, without the requirement of doping. Our

model can be realized in present experiments with bosonic mixtures that feature

simple on-site interactions, clearing the path to the observation of

supersolidity.

\\ ( http://arxiv.org/abs/0906.1110 , 551kb)

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arXiv:0906.1161

Date: Fri, 5 Jun 2009 16:18:28 GMT (34kb)

Title: Adiabatic dynamics in passage through a quantum critical point and

gapless phases

Authors: Debanjan Chowdhury, Uma Divakaran and Amit Dutta

Categories: cond-mat.stat-mech

Comments: 5 pages, 3 figures

\\

It is well known that the dynamics of a quantum system is always

non-adiabatic in passage through a quantum critical point and the defect

density in the final state following a quench shows a power-law decay with the

rate of quenching. We here propose a possible scenario of the adiabatic

dynamics of a quantum system even in passage through quantum critical points.

This is achieved by incorporating additional interactions which lead to quantum

critical behavior and gapless phases but do not participate in the time

evolution of the system. To illustrate the general argument, we study the

defect generation in the quantum critical dynamics of a spin-1/2 anisotropic

quantum XY spin chain with three spin interactions and a staggered magnetic

field. The system is driven by changing the staggered magnetic field linearly

with time $t$ as $t/\tau$ where $1/\tau$ determines the rate of quenching. In

the process, the system is swept across a quantum critical line followed by

gapless regions. We show that the density of defects in the final state after

the quenching scales as $1/\sqrt{\tau}$ if the strength of XY interaction

between the spins on even and odd sublattices is the same as the interaction

between the spins on odd and even sublattices. On the other hand, if these

interactions are different, the density of defects vanish exponentially with

$\tau$ contradicting the generic power-law scaling even though the system is

quenched across quantum critical lines and gapless phases in either cases.

\\ ( http://arxiv.org/abs/0906.1161 , 34kb)

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arXiv:0906.1031

Date: Fri, 5 Jun 2009 02:25:16 GMT (87kb,D)

Title: Continuous measurement feedback control of a Bose-Einstein condensate

using phase contrast imaging

Authors: S. S. Szigeti, M. R. Hush, A. R. R. Carvalho and J. J. Hope

Categories: quant-ph

Comments: 4 figures, 11 pages, submitted to PRA

\\

We consider the theory of feedback control of a Bose-Einstein condensate

(BEC) confined in a harmonic trap under a continuous measurement constructed

via non-destructive imaging. A filtering theory approach is used to derive a

stochastic master equation (SME) for the system from a general Hamiltonian

based upon system-bath coupling. Numerical solutions for this SME in the limit

of a single atom show that the final steady state energy is dependent upon the

measurement strength, the ratio of photon kinetic energy to atomic kinetic

energy, and the feedback strength. Simulations indicate that for a weak

measurement strength, feedback can be used to overcome heating introduced by

the scattering of light, thereby allowing the atom to be driven towards the

ground state.

\\ ( http://arxiv.org/abs/0906.1031 , 87kb)

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arXiv:0906.1239

Date: Sat, 6 Jun 2009 01:03:11 GMT (18kb)

Title: On the kinetic energy of unitary Fermi gas in a harmonic trap

Authors: Alexander L. Zubarev and Michael Zoubarev

Categories: cond-mat.quant-gas

Comments: 12 pages, 3 figures

\\

We have considered the orbital-free approximation of the kinetic energy

functional to investigate the zero temperature properties of dilute

harmonically trapped two component Fermi gas at unitarity. It is shown that our

approach provides a realible and inexpensive method to study superfluid

strongly interacting dilute Fermi gases.

\\ ( http://arxiv.org/abs/0906.1239 , 18kb)

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arXiv:0906.1337

Date: Sun, 7 Jun 2009 09:56:15 GMT (199kb,X)

Title: A sonic black hole in a density-inverted Bose-Einstein condensate

Authors: O. Lahav, A. Itah, A. Blumkin, C. Gordon, and J. Steinhauer

Categories: cond-mat.quant-gas

\\

We have created the analogue of a black hole in a Bose-Einstein condensate.

In this sonic black hole, sound waves, rather than light waves, cannot escape

the event horizon. The black hole is realized via a counterintuitive density

inversion, in which an attractive potential repels the atoms. This allows for

measured flow speeds which cross and exceed the speed of sound by an order of

magnitude. The Landau critical velocity is therefore surpassed. The point where

the flow speed equals the speed of sound is the event horizon. The effective

gravity is determined from the profiles of the velocity and speed of sound.

\\ ( http://arxiv.org/abs/0906.1337 , 199kb)

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arXiv:0906.1376

Date: Sun, 7 Jun 2009 18:45:02 GMT (8kb)

Title: Solution of the Stochastic Langevin Equations for Clustering of

Particles in Turbulent Flows in Terms of Wiener Path Integral

Authors: M. Chaichian, A. Tureanu, A. Zahabi

Categories: cond-mat.stat-mech

Comments: 11 pages

Report-no: HIP-2009-16/TH

\\

We present the solution for the joint probability densities of particles

suspended in a fluid under the effect of viscous and random forces, in terms of

the Wiener path integral. Our obtained exact solution, giving the expression

for the Lyapunov exponent, i) will provide the description of all the features

and the behaviour of such a system, e.g. the aggregation phenomenon recently

studied in the literature using certain approximations, ii) can be used to

determine the occurrence and the nature of the aggregation - non-aggregation

phase transition and iii) allows the use of a variety of approximation methods

appropriate for the physical conditions of the problem.

\\ ( http://arxiv.org/abs/0906.1376 , 8kb)

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arXiv:0906.1600

Date: Mon, 8 Jun 2009 21:04:55 GMT (717kb)

Title: Frustrated Bose condensates in optical lattices

Authors: T. Duric, D. K. K. Lee

Categories: cond-mat.quant-gas

Comments: 10 pages, 9 figures

\\

We study the Bose-condensed ground states of bosons in an optical lattice in

the presence of frustration due to an effective vector potential, for example,

due to lattice rotation. We use a mapping to a large-S frustrated magnet to

study quantum fluctuations in the condensed state. Quantum fluctuations are

introduced by considering a 1/S expansion around the classical ground state.

The results show that, within the large-S approach, the superfluid fraction and

the condensate fraction do not vanish even at the critical value of the

chemical potential where the system becomes a Mott insulator. However, for

cases with fewer than 1/3 flux quantum per lattice plaquette, we find that the

condensate depletion increases as the system approaches the Mott phase, giving

rise to the possibility of a non-condensed state before the Mott phase is

reached.

\\ ( http://arxiv.org/abs/0906.1600 , 717kb)

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arXiv:0906.1686

Date: Tue, 9 Jun 2009 10:31:43 GMT (24kb)

Title: Quantum entanglement of spin-1 bosons with coupled ground states in

optical lattices

Authors: B. \"Oztop, M. \"O. Oktel, \"O. E. M\"ustecapl\i o\u{g}lu and L. You

Categories: cond-mat.quant-gas

Comments: 18 pages, 8 figures. To be published in Journal of Physics B

\\

We examine particle entanglement, characterized by pseudo-spin squeezing, of

spin-1 bosonic atoms with coupled ground states in a one-dimensional optical

lattice. Both the superfluid and Mott-insulator phases are investigated

separately for ferromagnetic and antiferromagnetic interactions. Mode

entanglement is also discussed in the Mott insulating phase. The role of a

small but nonzero angle between the polarization vectors of counter-propagating

lasers forming the optical lattice on quantum correlations is investigated as

well.

\\ ( http://arxiv.org/abs/0906.1686 , 24kb)

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arXiv:0906.1765

Date: Tue, 9 Jun 2009 19:38:23 GMT (215kb)

Title: Non-destructive cavity QED probe of Bloch oscillations in a gas of

ultracold atoms

Authors: B. M. Peden, D. Meiser, M. L. Chiofalo, M. J. Holland

Categories: cond-mat.quant-gas

Comments: 8 pages, 6 figures, submitted to Phys. Rev. A

\\

We describe a scheme for probing a gas of ultracold atoms trapped in an

optical lattice and moving in the presence of an external potential. The probe

is non-destructive and uses the existing lattice fields as the measurement

device. Two counter-propagating cavity fields simultaneously set up a

conservative lattice potential and a weak quantum probe of the atomic motion.

Balanced heterodyne detection of the probe field at the cavity output along

with integration in time and across the atomic cloud yield information about

the atomic dynamics in a single run. The scheme is applied to a measurement of

the Bloch oscillation frequency for atoms moving in the presence of the local

gravitational potential. Signal-to-noise ratios are estimated to be as high as

$10^4$.

\\ ( http://arxiv.org/abs/0906.1765 , 215kb)

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arXiv:0906.1801

Date: Tue, 9 Jun 2009 18:52:55 GMT (106kb)

Title: Signature of the FFLO phase in the collective modes of a trapped

ultracold Fermi gas

Authors: Jonathan M. Edge, N.R. Cooper

Categories: cond-mat.quant-gas

Comments: 5 pages, 3 figures

\\

We study theoretically the collective modes of a two-component Fermi gas with

attractive interactions in a quasi-one-dimensional harmonic trap. We focus on

an imbalanced gas in the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase. Using a

mean-field theory, we study the response of the ground state to time-dependent

potentials. For potentials with short wavelengths, we find dramatic signatures

in the large-scale response of the gas which are characteristic of the FFLO

phase. This response provides an effective way to detect the FFLO state in

experiments.

\\ ( http://arxiv.org/abs/0906.1801 , 106kb)

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arXiv:0906.0333 (*cross-listing*)

Date: Mon, 1 Jun 2009 18:20:36 GMT (107kb)

Title: Critical point of the two-dimensional Bose gas: an S-matrix approach

Authors: Pye-Ton How and Andre' LeClair

Categories: math-ph cond-mat.quant-gas math.MP

Comments: 32 pages

\\

A new treatment of the critical point of the two-dimensional interacting Bose

gas is presented. In the lowest order approximation we obtain the critical

temperature T_c ~ 2 \pi n/[ m \log (2\pi/mg)], where n is the density, m the

mass, and g the coupling. This result is based on a new formulation of

interacting gases at finite density and temperature which is reminiscent of the

thermodynamic Bethe ansatz in one dimension. In this formalism, the basic

thermodynamic quantities are expressed in terms of a pseudo-energy. Consistent

resummation of 2-body scattering leads to an integral equation for the

pseudo-energy with a kernel based on the logarithm of the exact 2-body

S-matrix.

\\ ( http://arxiv.org/abs/0906.0333 , 107kb)

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arXiv:0906.1625

Date: Tue, 9 Jun 2009 02:19:23 GMT (121kb)

Title: On the Control of Tripod-Scheme Cold-Atom Wavepackets by non-Abelian

Geometric Phases

Authors: Qi Zhang, Jiangbin Gong, and C.H. Oh

Categories: quant-ph

Comments: 22 pages, 4 figures, submitted to Phys. Rev. A

\\

Tripod-scheme cold atoms interacting with laser beams have attracted

considerable interest for their role in synthesizing effective non-Abelian

vector potentials. Such effective vector potentials are exploited in our recent

work to realize an all-optical imprinting of geometric phases onto matter waves

[Zhang, Gong, and Oh, Phys. Rev. A 79, 043632 (2009)]. By working with two

specific laser beam displacement scenarios for the generation of geometric

phases and for the control of matter wave propagation, we demonstrate that a

geometric phase may be understood as a dynamical phase and a non-Abelian

geometric phase maybe understood as an effective Abelian geometric phase by

changing the frame of reference. Results enhance our understanding of geometric

phases as a fundamental element in quantum mechanics and help design better

schemes for the imprinting of geometric phases.

\\ ( http://arxiv.org/abs/0906.1625 , 121kb)

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arXiv:0906.1894

Date: Wed, 10 Jun 2009 09:23:32 GMT (324kb)

Title: Two-photon nonlinear spectroscopy of periodically trapped ultracold

atoms in a cavity

Authors: Tarun Kumar, Aranya B Bhattacherjee and ManMohan

Categories: cond-mat.quant-gas

Comments: 6 pages and 5 figures

\\

We study the transmission spectra of a Bose Einstein condensate confined in

an optical lattice interacting with two modes of a cavity via nonlinear

two-photon transition. In particular we show that a nonlinear two-photon

interaction between the superfluid (SF) phase and the Mott insulating (MI)

phase of a Bose-Einstein condensate (BEC) and the cavity field show

qualitatively different transmission spectra compared to the one-photon

interaction. We found that when the BEC is in the Mott state, the usual normal

mode splitting present in the one-photon transition is missing in the

two-photon interaction. When the BEC is in the superfluid state, the

transmission spectra shows the usual multiple lorentzian structure. However the

separation between the lorentzians for the two-photon case is much larger than

that for the one-photon case. This study could form the basis for

non-destructive high resolution Rydberg spectroscopy of ultracold atoms or

two-photon spectroscopy of a gas of ultracold atomic hydrogen.

\\ ( http://arxiv.org/abs/0906.1894 , 324kb)

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arXiv:0906.1937

Date: Wed, 10 Jun 2009 13:53:25 GMT (239kb)

Title: Polarized Fermi gases in asymmetric optical lattices

Authors: Xiaoling Cui and Yupeng Wang

Categories: cond-mat.quant-gas cond-mat.supr-con

Comments: 8 pages, 7 figures

\\

We present the zero temperature phase diagrams of imbalanced two species

fermions in asymmetric optical lattices, based on the exact spectrum rather

than the Fermi-Hubbard model. The crossover of the system from free 3D to

quasi-2D or quasi-1D can be driven by increasing the lattice potential along

one or two directions. We investigate the influence of lattices to the BCS

state, Sarma or breached pair state, normal state, phase separation and

particularly Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state. With fixed s-wave

interactions and given dimension, the strength of FFLO state can be tuned by

both the lattice potentials and particle densities. Compared with a 3D free

Fermi gas, the system with reduced dimensionality by optical lattices is found

to be much more favorable to FFLO pairing. The effect of asymmetric optical

lattices on the phase profile in a harmonic trap is also studied by using LDA.

\\ ( http://arxiv.org/abs/0906.1937 , 239kb)

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arXiv:0906.1640 (*cross-listing*)

Date: Tue, 9 Jun 2009 06:12:03 GMT (1045kb,D)

Title: An introduction to effective low-energy Hamiltonians in condensed matter

physics and chemistry

Authors: B. J. Powell

Categories: physics.chem-ph cond-mat.quant-gas cond-mat.stat-mech

cond-mat.str-el

Comments: 27 pages, 16 figures

\\

These lecture notes introduce some simple effective Hamiltonians (also known

as semi-empirical models) that have widespread applications to solid state and

molecular systems. They are aimed as an introduction to a beginning graduate

student. I also hope that it may help to break down the divide between the

physics and chemistry literatures. After a brief introduction to second

quantisation notation, which is used extensively, I focus of the "four H's":

the Huckel (or tight binding), Hubbard, Heisenberg and Holstein models. Some

other related models, such as the Pariser-Parr-Pople model, the extended

Hubbard model, multi-orbital models and the ionic Hubbard model, are also

discussed. Finally, I discuss the epistemological basis of effective

Hamiltonians and compare and contrast this with that of ab initio methods as

well as discussing the problem of parametrising effective Hamiltonians.

\\ ( http://arxiv.org/abs/0906.1640 , 1045kb)

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arXiv:0906.1968

Date: Wed, 10 Jun 2009 16:10:36 GMT (32kb)

Title: Delirium Quantum

Authors: Christopher A. Fuchs

Categories: quant-ph

Comments: Stuffed away in a conference proceedings for years, I finally worked

up the nerve to post this because I needed to cite it in a paper with some

proper equations. Stay posted

Journal-ref: AIP Conference Proceedings 889, Foundations of Probability and

Physics -- 4, G. Adenier et al eds., (American Institute of Physics,

Melville, NY, 2007), pp. 438-462

\\

This pseudo-paper consists of excerpts drawn from two of my quantum-email

samizdats. Section 1 draws a picture of a physical world whose essence is

``Darwinism all the way down.'' Section 2 outlines how quantum theory should be

viewed in light of this, i.e., as being an expression of probabilism (in Bruno

de Finetti or Richard Jeffrey's sense) all the way back up. Section 3 describes

how the idea of ``identical'' quantum measurement outcomes, though sounding

atomistic in character, nonetheless meshes well with a Jamesian style ``radical

pluralism.'' Sections 4 and 5 further detail how quantum theory should not be

viewed so much as a ``theory of the world,'' but rather as a theory of

decision-making for agents immersed within a world of a particular

character--the quantum world. Finally, Sections 6 and 7 attempt to sketch the

very positive sense in which quantum theory is incomplete, but still just as

complete is it can be. In total, I hope these heady speculations convey some of

the excitement and potential I see for the malleable world quantum mechanics

hints of.

\\ ( http://arxiv.org/abs/0906.1968 , 32kb)

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arXiv:0906.2110

Date: Thu, 11 Jun 2009 14:00:58 GMT (1305kb)

Title: Number Fluctuations and Energy Dissipation in Sodium Spinor Condensates

Authors: Yingmei Liu, Eduardo Gomez, Stephen E. Maxwell, Lincoln D. Turner,

Eite Tiesinga and Paul D. Lett

Categories: cond-mat.other

Journal-ref: Phys. Rev. Lett. 102, 225301 (2009)

\\

We characterize fluctuations in atom number and spin populations in F=1

sodium spinor condensates. We find that the fluctuations enable a quantitative

measure of energy dissipation in the condensate. The time evolution of the

population fluctuations shows a maximum. We interpret this as evidence of a

dissipation-driven separatrix crossing in phase space. For a given initial

state, the critical time to the separatrix crossing is found to depend

exponentially on the magnetic field and linearly on condensate density. This

crossing is confirmed by tracking the energy of the spinor condensate as well

as by Faraday rotation spectroscopy. We also introduce a phenomenological model

that describes the observed dissipation with a single coefficient.

\\ ( http://arxiv.org/abs/0906.2110 , 1305kb)

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arXiv:0906.2115

Date: Thu, 11 Jun 2009 14:21:08 GMT (880kb)

Title: Unconventional superfluidity in Bose-Fermi Mixtures

Authors: O. Dutta and M. Lewenstein

Categories: cond-mat.quant-gas cond-mat.supr-con

\\

Pairing between fermions that attract each other, reveal itself to the

macroscopic world in the form of superfluidity. Since the discovery of

fermionic superfluidity, intense search has been going on to find various

unconventional forms of fermion pairing as well as to increase the transition

temperature. Here, we show that a two dimensional mixture of single-component

fermions and dipolar bosons allows to reach experimentally feasible superfluid

transition temperatures for non-standard pairing symmetries. Excitations in

these superfluids are anyonic and their statistics depends on the order of

their permutations, i.e is non-Abelian. Our results provide for the first time

an example of a highly tunable system which exhibits various kind of pairing

symmetry and high transition temperature. Additionally, they provide a

playground to observe anyonic excitations and their braiding properties.

\\ ( http://arxiv.org/abs/0906.2115 , 880kb)

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arXiv:0906.2126

Date: Thu, 11 Jun 2009 14:56:34 GMT (262kb)

Title: Supersolid phase with cold polar molecules on a triangular lattice

Authors: L. Pollet, J. D. Picon, H.P. Buechler, M. Troyer

Categories: cond-mat.stat-mech cond-mat.quant-gas

Comments: 4 pages, 4 figures

\\

We study a system of heteronuclear molecules on a triangular lattice and

analyze the potential of this system for the experimental realization of a

supersolid phase. The ground state phase diagram contains superfluid, solid and

supersolid phases. At finite temperatures and strong interactions there is an

additional emulsion region, in contrast to similar models with short-range

interactions. We derive the maximal critical temperature $T_c$ and the

corresponding entropy $S/N = 0.04(1)$ for supersolidity and find feasible

experimental conditions for its realization.

\\ ( http://arxiv.org/abs/0906.2126 , 262kb)

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arXiv:0906.2141

Date: Thu, 11 Jun 2009 15:50:09 GMT (166kb)

Title: Fermions in 2D Optical Lattices: Temperature and Entropy Scales for

Observing Antiferromagnetism and Superfluidity

Authors: Thereza Paiva, Richard Scalettar, Mohit Randeria, and Nandini Trivedi

Categories: cond-mat.quant-gas cond-mat.str-el

Comments: 4 pages, 4 figures

\\

One of the major challenges in realizing antiferromagnetic and superfluid

phases in optical lattices is the ability to cool fermions. We determine

constraints on the entropy for observing these phases in two-dimensional

Hubbard models. We investigate antiferromagnetic correlations in the repulsive

model at half filling and superfluidity of s-wave pairs in the attractive case

away from half filling using determinantal quantum Monte Carlo simulations that

are free of the fermion sign problem. We find that an entropy per particle

~log(2) is sufficient to observe the charge gap in the repulsive Hubbard model

or the pairing pseudogap in the attractive case. Observing antiferromagnetic

correlations or superfluidity in 2D systems requires a further reduction in

entropy by a factor of three or more. In contrast to higher dimensions, we find

that adiabatic cooling is not useful to achieve the required low temperatures.

We also show that double occupancy measurements are useful for thermometry for

temperatures greater than the nearest-neighbor hopping.

\\ ( http://arxiv.org/abs/0906.2141 , 166kb)

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arXiv:0906.2150

Date: Thu, 11 Jun 2009 17:18:45 GMT (764kb)

Title: Counterflow and paired superfluidity in one-dimensional Bose mixtures in

optical lattices

Authors: Anzi Hu, L. Mathey, Ippei Danshita, Eite Tiesinga, Carl J. Williams

and Charles W. Clark

Categories: cond-mat.quant-gas

Comments: 13 pages,13 figures

\\

We study the quantum phases of mixtures of ultra-cold bosonic atoms held in

an optical lattice that confines motion or hopping to one spatial dimension.

The phases are found by using Tomonaga-Luttinger liquid theory as well as the

numerical method of time evolving block decimation (TEBD). We consider a binary

mixture with repulsive intra-species interactions, and either repulsive or

attractive inter-species interaction. For a homogeneous system, we find paired-

and counterflow-superfluid phases at different filling and hopping energies. We

also predict parameter regions in which these types of superfluid order coexist

with charge density wave order. We show that the Tomonaga-Luttinger liquid

theory and TEBD qualitatively agree on the location of the phase boundary to

superfluidity. We then describe how these phases are modified and can be

detected when an additional harmonic trap is present. In particular, we show

how experimentally measurable quantities, such as time-of-flight images and the

structure factor, can be used to distinguish the quantum phases. Finally, we

suggest applying a Feshbach ramp to detect the paired superfluid state, and a

$\pi/2$ pulse followed by Bragg spectroscopy to detect the counterflow

superfluid phase.

\\ ( http://arxiv.org/abs/0906.2150 , 764kb)

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arXiv:0906.2174

Date: Thu, 11 Jun 2009 18:20:34 GMT (1021kb)

Title: Angular collapse of dipolar Bose-Einstein condensates

Authors: Ryan M. Wilson, Shai Ronen and John L. Bohn

Categories: cond-mat.quant-gas cond-mat.stat-mech

Comments: 19 pages (preprint), 6 figure, submitted to PRA

\\

We explore the structure and dynamics of dipolar Bose-Einstein condensates

(DBECs) near their threshold for instability. Near this threshold a DBEC may

exhibit nontrivial, biconcave density distributions, which are associated with

instability against collapse into ``angular roton'' modes. Here we discuss

experimental signatures of these novel features. In the first, we infer local

collapse of the DBEC from the experimental stability diagram. In the second, we

explore the dynamics of collapse and find that a nontrivial angular

distribution is a signature of the DBEC possessing a biconcave structure.

\\ ( http://arxiv.org/abs/0906.2174 , 1021kb)

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arXiv:0906.2019 (*cross-listing*)

Date: Wed, 10 Jun 2009 21:20:08 GMT (1465kb,D)

Title: Bose-Einstein Condensation of strongly interacting bosons: from liquid

${}^4$He to QCD monopoles

Authors: Marco Cristoforetti and Edward Shuryak

Categories: hep-ph cond-mat.stat-mech

\\

Starting from classic work of Feynman on the $\lambda$-point of liquid

Helium, we show that his idea of universal action per particle at the BEC

transition point is much more robust that it was known before. Using a simple

"moving string model" for supercurrent and calculating the action, both

semiclassically and numerically, we show that the critical action is the same

for noninteracting and strongly interacting systems such as liquid ${}^4$He.

Inversely, one can obtain accurate dependence of critical temperature on

density: one important consequence is that high density (solid) He cannot be a

BEC state of He atoms, with upper density accurately matching the observations.

We then use this model for the deconfinement phase transition of QCD-like gauge

theories, treated as BEC of (color)magnetic monopoles. We start with

Feynman-like approach without interaction, estimating the monopole mass at

$T_c$. Then we include monopole's Coulomb repulsion, and formulate a relation

between the mass, density and coupling which should be fulfilled at the

deconfinement point. We end up proposing various ways to test on the lattice

whether it is indeed the BEC point for monopoles.

\\ ( http://arxiv.org/abs/0906.2019 , 1465kb)

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arXiv:0906.2121

Date: Thu, 11 Jun 2009 15:16:07 GMT (2924kb)

Title: How to characterize the dynamics of cold atoms in non dissipative

optical lattices?

Authors: Daniel Hennequin (PhLAM), Philippe Verkerk (PhLAM)

Categories: physics.atom-ph

\\

We examine here the classical dynamics of cold atoms in square optical

lattices, i.e. lattices obtained with two orthogonal stationary plane waves.

Contrary to much of the past studies in this domain, the potential is here time

independent and non dissipative. We show that, as a function of the

experimental parameters, a very different behavior is obtained, both for the

dynamics of atoms trapped inside individual sites, and for atoms travelling

between sites: inside the sites, chaos may be a main regime or, on the

contrary, may be negligible; outside the sites, chaos sometimes coexists with

other regimes. We discuss what are the consequences of these differences on the

macroscopic behavior of the atoms in the lattice, and we propose experimental

measurements able to characterize these dynamics and to distinguish between the

different cases.

\\ ( http://arxiv.org/abs/0906.2121 , 2924kb)

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arXiv:0904.1160

replaced with revised version Mon, 8 Jun 2009 17:16:30 GMT (514kb)

Title: Spin dynamics and structure formation in a spin-1 condensate in a

magnetic field

Authors: Jordi Mur-Petit (UCL)

Categories: cond-mat.quant-gas quant-ph

Comments: 8 pages, 5 figures. Matches published version

Journal-ref: Physical Review A 79, 063603 (2009)

DOI: 10.1103/PhysRevA.79.063603

\\ ( http://arxiv.org/abs/0904.1160 , 514kb)

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arXiv:0904.3911

replaced with revised version Tue, 9 Jun 2009 16:19:19 GMT (266kb)

Title: Quantum linear Boltzmann equation

Authors: Bassano Vacchini, Klaus Hornberger

Categories: quant-ph math-ph math.MP

Comments: 63 pages, 6 figures; v2:minor corrections&updates, to appear in

Physics Reports

\\ ( http://arxiv.org/abs/0904.3911 , 266kb)

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arXiv:0905.1492

replaced with revised version Wed, 10 Jun 2009 17:42:07 GMT (210kb)

Title: Analytic description of atomic interaction at ultracold temperatures:

the case of a single channel

Authors: Bo Gao

Categories: physics.atom-ph physics.chem-ph

Comments: 12 pages, 4 figures, minor corrections, to be published in PRA

\\ ( http://arxiv.org/abs/0905.1492 , 210kb)

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arXiv:0901.1415

replaced with revised version Thu, 11 Jun 2009 08:05:02 GMT (337kb)

Title: Unconventional Bose-Einstein Condensations Beyond the "No-node" Theorem

Authors: Congjun Wu

Categories: cond-mat.supr-con cond-mat.str-el

Journal-ref: Mod. Phys. Lett. B 23, 1 (2009)

DOI: 10.1142/S0217984909017777

\\ ( http://arxiv.org/abs/0901.1415 , 337kb)

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arXiv:0904.2564

replaced with revised version Thu, 11 Jun 2009 13:46:54 GMT (563kb)

Title: Emergence of turbulence in an oscillating Bose-Einstein condensate

Authors: E.A.L. Henn, J.A.Seman, G.Roati, K.M.F. Magalhaes and V.S. Bagnato

Categories: cond-mat.quant-gas cond-mat.mes-hall

Comments: accepted for Phys. Rev. Lett

\\ ( http://arxiv.org/abs/0904.2564 , 563kb)

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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/ ========================================================================= Legal stuff: Unless stated otherwise, this e-mail represents only the views of the sender and not the views of the University of Queensland ========================================================================= _______________________________________________ Matts-arxiv mailing list Matts-arxiv_at_lists.sps.uq.edu.auReceived on Fri Jul 10 2009 - 16:01:09 EST

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