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

Date: Sat, 19 Aug 2006 00:52:32 +1000 (EST)

Date: Sat, 19 Aug 2006 00:52:32 +1000 (EST)

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

Hi all,

Things should be back to normal from next week - hopefully I will manage to

board a plane from London Heathrow on Sunday back to Brisbane.

Hope page: http://www.physics.uq.edu.au/people/mdavis/matts_arXiv/

The abstracts:

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Paper: cond-mat/0608291

Date: Sun, 13 Aug 2006 21:41:56 GMT (280kb)

Title: Collective oscillations of dipolar Bose-Einstein condensates and

accurate comparison between contact and dipolar interaction

Authors: S. Giovanazzi, L. Santos, T. Pfau

Comments: 4 pages, brief report

Subj-class: Other

\\

We propose a scheme for the measurement of the s-wave scattering length $a$

of an atom or molecule with significant dipole-dipole interaction with an

accuracy at the percent level. The frequencies of the collective oscillations

of a Bose-Einstein condensate are shifted by the magnetic dipole interaction.

The shift is polarization dependent and proportional to the ratio

$\epsilon_{dd}$ of dipolar and s-wave coupling constants. Measuring the

differences in the frequencies for different polarization we can extract the

value of $\epsilon_{dd}$ and thus measure $a$. We calculate the frequency

shifts for a large variety of non-axisymmetric harmonic traps in the

Thomas-Fermi limit and find optimal trapping geometries to maximize the shifts.

\\ ( http://arXiv.org/abs/cond-mat/0608291 , 280kb)

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Paper: cond-mat/0608306

Date: Mon, 14 Aug 2006 08:58:56 GMT (90kb)

Title: Quantum polarization spectroscopy of ultracold spinor gases

Authors: K. Eckert, L. Zawitkowski, A. Sanpera, M. Lewenstein, E.S. Polzik

Comments: 5 pages, 1 figure

Subj-class: Other

\\

We propose a method for the detection of ground state quantum phases of

spinor gases through a series of two quantum nondemolition measurements

performed by sending off-resonant, polarized light pulses through the gas.

Signatures of various mean-field as well as strongly-correlated phases of F=1

and F=2 spinor gases obtained by detecting quantum fluctuations and mean values

of polarization of transmitted light are identified.

\\ ( http://arXiv.org/abs/cond-mat/0608306 , 90kb)

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Paper: cond-mat/0608316

Date: Mon, 14 Aug 2006 19:35:49 GMT (898kb)

Title: Vortex in a trapped Bose-Einstein condensate with dipole-dipole

interactions

Authors: Duncan H. J. O'Dell, Claudia Eberlein

Comments: 12 pages, 12 figures

Subj-class: Other

\\

We calculate the critical rotation frequency at which a vortex state becomes

energetically favorable over the vortex-free ground state in a harmonically

trapped Bose-Einstein condensate whose atoms have dipole-dipole interactions as

well as the usual s-wave contact interactions. In the Thomas-Fermi

(hydrodynamic) regime, dipolar condensates in oblate cylindrical traps (with

the dipoles aligned along the axis of symmetry of the trap) tend to have lower

critical rotation frequencies than their purely s-wave contact interaction

counterparts. The converse is true for dipolar condensates in prolate traps.

Quadrupole excitations and centre of mass motion are also briefly discussed as

possible competing mechanisms to a vortex as means by which superfluids with

partially attractive interactions might carry angular momentum

\\ ( http://arXiv.org/abs/cond-mat/0608316 , 898kb)

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Paper: cond-mat/0606330

replaced with revised version Mon, 14 Aug 2006 15:10:48 GMT (623kb)

Title: Sarma Phase in Trapped Unbalanced Fermi Gases

Authors: K. B. Gubbels, M. W. J. Romans, and H. T. C. Stoof

Comments: 4 pages, 3 figures

Subj-class: Statistical Mechanics

\\ ( http://arXiv.org/abs/cond-mat/0606330 , 623kb)

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Paper: cond-mat/0608154

replaced with revised version Sat, 12 Aug 2006 20:19:45 GMT (16kb)

Title: Pairing and Superfluid Properties of Dilute Fermion Gases at Unitarity

Authors: Vamsi K. Akkineni, D.M. Ceperley, Nandini Trivedi

Comments: 4 pages, 4 figures, To be submitted to PRL Minor errors corrected

Subj-class: Statistical Mechanics; Superconductivity

\\ ( http://arXiv.org/abs/cond-mat/0608154 , 16kb)

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Paper: quant-ph/0608109

Date: Sun, 13 Aug 2006 07:22:55 GMT (68kb)

Title: Controlled splitting of an atomic wave packet

Authors: M. Zhang, P. Zhang, M. S. Chapman and L. you

Comments: 4 pages, 4 figures. Accepted by Phys. Rev. Lett

\\

We propose a simple scheme capable of adiabatically splitting an atomic wave

packet using two independent translating traps. Implemented with optical dipole

traps, our scheme allows a high degree of flexibility for atom interferometry

arrangements and highlights its potential as an efficient and high fidelity

atom optical beam splitter.

\\ ( http://arXiv.org/abs/quant-ph/0608109 , 68kb)

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Paper: cond-mat/0608321

Date: Tue, 15 Aug 2006 07:20:45 GMT (109kb)

Title: Unitary Fermi gas at finite temperature in the epsilon expansion

Authors: Yusuke Nishida

Comments: 12 pages, 6 figures, revtex4

Report-no: INT-PUB 06-13, TKYNT-06-11

Subj-class: Other

\\

Thermodynamics of the unitary Fermi gas at finite temperature is investigated

from the perspective of the expansion over epsilon=4-d with d being the

dimensionality of space. We show that the thermodynamics is dominated by

bosonic excitations in the low temperature region where T<<Tc. Analytic

formulas for the thermodynamic functions as functions of the temperature are

derived to the lowest order in epsilon in this region. In the high temperature

region where T~Tc, bosonic and fermionic quasiparticles are excited and we

determine the critical temperature Tc and the thermodynamic functions around Tc

to the leading and next-to-leading orders in epsilon.

\\ ( http://arXiv.org/abs/cond-mat/0608321 , 109kb)

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Paper: cond-mat/0608335

Date: Tue, 15 Aug 2006 16:58:47 GMT (148kb)

Title: Superfluid -- Mott insulator transition of ultracold gases in optical

resonators

Authors: Jonas Larson, Bogdan Damski, Giovanna Morigi, Maciej Lewenstein

Comments: 4 pages, 4 figures

Report-no: LAUR-06-5423

Subj-class: Other

\\

The physics of a ultracold atomic gas in the potential formed inside a pumped

optical resonator is critically affected by the photon-mediated interaction

between the atoms. The presence of the atoms determines the cavity resonance,

and thus the intracavity field amplitude, which then determines atomic

localization and the quantum phase of the gas. We study the superfluid -- Mott

insulator quantum phase transition in this system in one dimension. The

coefficients of the effective Bose-Hubbard model depend non-linearly on the

number of atoms, and have to be evaluated self-consistently. We predict the

existence of overlapping, competing Mott phases and bistable behavior in the

vicinity of the shifted cavity resonance, controlled by the pump parameters.

\\ ( http://arXiv.org/abs/cond-mat/0608335 , 148kb)

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Paper: cond-mat/0601604

replaced with revised version Tue, 15 Aug 2006 08:15:15 GMT (291kb)

Title: Thermal fluctuations of vortex clusters in quasi-two-dimensional

Bose-Einstein condensate

Authors: W. V. Pogosov and K. Machida

Comments: 8 pages, 3 figures; final version, accepted for publication in Phys.

Rev. A

Subj-class: Statistical Mechanics; Other

\\ ( http://arXiv.org/abs/cond-mat/0601604 , 291kb)

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Paper: cond-mat/0602119

replaced with revised version Tue, 15 Aug 2006 08:06:32 GMT (31kb)

Title: Effect of thermal fluctuations on spin degrees of freedom in spinor

Bose-Einstein condensates

Authors: W. V. Pogosov, K. Machida

Comments: 5 pages, 2 figures; final version, accepted for publication in Phys.

Rev. A

Subj-class: Other

\\ ( http://arXiv.org/abs/cond-mat/0602119 , 31kb)

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Paper: cond-mat/0602667

replaced with revised version Tue, 15 Aug 2006 08:46:43 GMT (239kb)

Title: Twisted vortex state

Authors: V.B. Eltsov, A.P. Finne, R. Hanninen, J. Kopu, M. Krusius, M. Tsubota,

E.V. Thuneberg

Comments: 5 pages, 4 figures, RevTeX file, corrected after the referee comments

Subj-class: Soft Condensed Matter

Journal-ref: Phys. Rev. Lett. 96, 215302 (2006)

DOI: 10.1103/PhysRevLett.96.215302

\\ ( http://arXiv.org/abs/cond-mat/0602667 , 239kb)

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Paper: cond-mat/0604505

replaced with revised version Tue, 15 Aug 2006 07:58:03 GMT (82kb)

Title: Cyclic phase in F=2 spinor condensate: Long-range order, kinks, and

roughening transition

Authors: W. V. Pogosov, K. Machida

Comments: 6 pages, 1 figure; final version, accepted for publication in Phys.

Rev. A

Subj-class: Statistical Mechanics

\\ ( http://arXiv.org/abs/cond-mat/0604505 , 82kb)

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Paper: cond-mat/0608135

replaced with revised version Tue, 15 Aug 2006 06:33:47 GMT (382kb)

Title: Disruption of reflecting Bose-Einstein condensates due to quantum noise

and modulational instability

Authors: R.G. Scott, D.A.W. Hutchinson and C.W. Gardiner

Comments: 5 figures

Subj-class: Other

\\ ( http://arXiv.org/abs/cond-mat/0608135 , 382kb)

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Paper: cond-mat/0608350

Date: Wed, 16 Aug 2006 08:41:46 GMT (114kb)

Title: Mean-field theory for Bose-Hubbard Model under a magnetic field

Authors: M.O. Oktel, M. Nita, B. Tanatar

Comments: 11 pages, 7 figures

Subj-class: Statistical Mechanics

\\

We consider the superfluid-insulator transition for cold bosons under an

effective magnetic field. We investigate how the applied magnetic field affects

the Mott transition within mean field theory and find that the critical hopping

strength $(t/U)_c$, increases with the applied field. The increase in the

critical hopping follows the bandwidth of the Hofstadter butterfly at the given

value of the magnetic field. We also calculate the magnetization and superfluid

density within mean field theory.

\\ ( http://arXiv.org/abs/cond-mat/0608350 , 114kb)

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Paper: cond-mat/0608351

Date: Wed, 16 Aug 2006 09:46:15 GMT (69kb)

Title: Exact numerical simulations of a one-dimensional, trapped Bose gas

Authors: Bernd Schmidt, Michael Fleischhauer

Comments: 4 pages, 5 figures

Subj-class: Other

\\

We analyze the ground-state and low-temperature properties of a

one-dimensional Bose gas in a harmonic trapping potential using the numerical

density matrix renormalization group. Calculations cover the whole range from

the Bogoliubov limit of weak interactions to the Tonks-Girardeau limit. Local

quantities such as density and local three-body correlations are calculated and

shown to agree very well with analytic predictions within a local density

approximation. The transition between temperature dominated to quantum

dominated correlation is determined and it is shown that despite the presence

of the harmonic trapping potential first-order correlations display over a

large range the algebraic decay of a harmonic fluid with a Luttinger parameter

determined by the density at the trap center.

\\ ( http://arXiv.org/abs/cond-mat/0608351 , 69kb)

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Paper: cond-mat/0608355

Date: Wed, 16 Aug 2006 17:40:16 GMT (638kb)

Title: A Quantum Top Inside a Bose Josephson Junction

Authors: Ingrid Bausmerth, Uwe R. Fischer, Anna Posazhennikova

Comments: 4 pages of RevTex4, 4 figures

Subj-class: Other

\\

We consider an atomic quantum dot confined between two weakly-coupled

Bose-Einstein condensates, where the dot serves as an additional tunneling

channel. It is shown that the thus-embedded atomic quantum dot is a pseudospin

subject to an external torque, and therefore equivalent to a quantum top. We

demonstrate by numerical analysis of the time-dependent coupled evolution

equations that this microscopic quantum top is very sensitive to any deviation

from linear oscillatory behavior of the condensates. In certain special cases,

the dot can even induce or modify the tunneling between the macroscopic

condensates in the two wells.

\\ ( http://arXiv.org/abs/cond-mat/0608355 , 638kb)

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Paper: cond-mat/0604184

replaced with revised version Wed, 16 Aug 2006 03:14:22 GMT (29kb)

Title: Two-species fermion mixtures with population imbalance

Authors: M. Iskin and C. A. R. Sa de Melo

Comments: 4 pages with 3 figures, accepted version to PRL

Subj-class: Superconductivity; Other

\\ ( http://arXiv.org/abs/cond-mat/0604184 , 29kb)

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Paper: cond-mat/0608365

Date: Thu, 17 Aug 2006 19:53:31 GMT (91kb)

Title: Sagnac interference in Carbon nanotube loops

Authors: Gil Refael, Jinseong Heo, Marc Bockrath

Comments: 5 pages, 4 figures

Subj-class: Mesoscopic Systems and Quantum Hall Effect; Strongly Correlated

Electrons

\\

In this paper we study electron interference in nanotube loops. The

conductance as a function of the applied voltage is shown to oscillate due to

interference between electron beams traversing the loop in two opposite

directions, with slightly different velocities. The period of these

oscillations with respect to the gate voltage, as well as the temperatures

required for the effect to appear, are shown to be much larger than those of

the related Fabry-Perot interference. This effect is analogous to the Sagnac

effect in light interferometers. We calculate the effect of interactions on the

period of the oscillations, and show that even though interactions destroy much

of the near-degeneracy of velocities in the symmetric spin channel, the slow

interference effects survive.

\\ ( http://arXiv.org/abs/cond-mat/0608365 , 91kb)

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Paper: cond-mat/0608370

Date: Wed, 16 Aug 2006 22:26:01 GMT (193kb)

Title: Atom trapping with a thin magnetic film

Authors: Micah Boyd, Erik W. Streed, Patrick Medley, Gretchen K. Campbell,

Jongchul Mun, Wolfgang Ketterle, David E. Pritchard

Comments: 4 pages, 5 figures

Subj-class: Other

\\

We have created a $^{87}$Rb Bose-Einstein condensate in a magnetic trapping

potential produced by a hard disk platter written with a periodic pattern. Cold

atoms were loaded from an optical dipole trap and then cooled to BEC on the

surface with radiofrequency evaporation. Fragmentation of the atomic cloud due

to imperfections in the magnetic structure was observed at distances closer

than 40 $\mu$m from the surface. Attempts to use the disk as an atom mirror

showed dispersive effects after reflection.

\\ ( http://arXiv.org/abs/cond-mat/0608370 , 193kb)

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Paper: cond-mat/0603772

replaced with revised version Wed, 16 Aug 2006 21:06:05 GMT (136kb)

Title: A Bose-Einstein condensate interferometer with macroscopic arm

separation

Authors: O. Garcia, B. Deissler, K. J. Hughes, J. M. Reeves and C.A. Sackett

Comments: 4 pages, 3 figures

Subj-class: Other

\\ ( http://arXiv.org/abs/cond-mat/0603772 , 136kb)

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Paper: cond-mat/0604638

replaced with revised version Thu, 17 Aug 2006 16:17:29 GMT (363kb)

Title: Surface Tension in Unitary Fermi Gases with Population Imbalance

Authors: Theja N. De Silva, Erich J. Mueller

Comments: 4 pages, 4 figures, Published version

Subj-class: Other

Journal-ref: Phys. Rev. Lett. 97, 070402 (2006)

DOI: 10.1103/PhysRevLett.97.070402

\\ ( http://arXiv.org/abs/cond-mat/0604638 , 363kb)

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Paper: quant-ph/0608133

Date: Thu, 17 Aug 2006 13:44:49 GMT (90kb)

Title: High fidelity teleportation between light and atoms

Authors: K. Hammerer, E.S. Polzik, J.I. Cirac

Comments: 5 pages, 3 figures, submitted to PRA

\\

We show how high fidelity quantum teleportation of light to atoms can be

achieved in the same setup as was used in the recent experiment [J. Sherson

et.al., quant-ph/0605095, accepted by Nature], where such an inter-species

quantum state transfer was demonstrated for the first time. Our improved

protocol takes advantage of the rich multimode entangled structure of the state

of atoms and scattered light and requires simple post-processing of homodyne

detection signals and squeezed light in order to achieve fidelities up to 90%

(85%) for teleportation of coherent (qubit) states under realistic experimental

conditions. The remaining limitation is due to atomic decoherence and light

losses.

\\ ( http://arXiv.org/abs/quant-ph/0608133 , 90kb)

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Paper: physics/0608183

Date: Thu, 17 Aug 2006 17:30:12 GMT (137kb)

Title: Superiority of the $h$-index over the Impact Factor for Physics

Authors: Casey W. Miller

Comments: 4 pages, 3 figures; Submitted to Am. J. Phys. (cordially rejected by

Nat. Phys.)

Subj-class: Physics and Society

\\

Focusing specifically on physics periodicals, I show that the journal Impact

Factor is not correlated with Hirsch's $h$-index. This implies that the Impact

Factor is not a good measure of research quality or influence because the

$h$-index is a reflection of peer review, and thus a strong indicator of

research quality. The impact gap between multidisciplinary journals and

physics-only journals is significantly reduced when $h$ is used instead of the

Impact Factor. Additionally, the impact of journals specializing in review

articles is inherently deflated using $h$ because of the limited number of

annual publications in such periodicals. Finally, a reordering of the top

ranking journals occurs with $h$ when only the physics articles of

multidisciplinary journals are considered, falling more in line with the

average physicist's interpretation of a journal's prestige.

\\ ( http://arXiv.org/abs/physics/0608183 , 137kb)

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Till next week,

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/ ========================================================================= 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 Sat Aug 19 2006 - 00:52:32 EST

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