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

Date: Mon, 25 Sep 2006 10:47:29 +1000 (EST)

Date: Mon, 25 Sep 2006 10:47:29 +1000 (EST)

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

This week is the mid-semester break... so things are back on schedule!

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

The abstracts:

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Paper: cond-mat/0609417

Date: Mon, 18 Sep 2006 10:05:43 GMT (454kb)

Title: Quantum depletion of collapsing Bose-Einstein condensates

Authors: S. Wuester, B. J. Dabrowska-Wuester, A. S. Bradley, M. J. Davis, P. B.

Blakie, J. J. Hope and C. M. Savage

Comments: 8 pages, 4 figures

Subj-class: Other

\\

We perform the first numerical three-dimensional studies of quantum field

effects in the Bosenova experiment on collapsing condensates by E. Donley et

al. [Nature 415, 39 (2002)] using the exact experimental geometry. In a

stochastic truncated Wigner simulation of the collapse, the collapse times are

larger than the experimentally measured values. We find that a finite

temperature initial state leads to an increased creation of uncondensed atoms,

but not to a reduction of the collapse time. A comparison of the time-dependent

Hartree-Fock-Bogoliubov and Wigner methods for the more tractable spherical

trap shows excellent agreement between the uncondensed populations. We conclude

that the discrepancy between the experimental and theoretical values of the

collapse time cannot be explained by quantum fluctuations or finite temperature

effects.

\\ ( http://arXiv.org/abs/cond-mat/0609417 , 454kb)

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Paper: cond-mat/0603299

replaced with revised version Mon, 18 Sep 2006 15:08:10 GMT (27kb)

Title: Fermions in optical lattices near a Feshbach resonance: from band

insulator to Mott insulator

Authors: A. F. Ho

Comments: 4 pages, 2 .eps files. Version essentially as published

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

Electrons

\\ ( http://arXiv.org/abs/cond-mat/0603299 , 27kb)

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Paper: cond-mat/0603489

replaced with revised version Sun, 17 Sep 2006 19:41:18 GMT (16kb)

Title: Comment on "Pairing and Phase Separation in a Polarized Fermi Gas" by G.

B. Partridge, W. Li, R. I. Kamar, Y. Liao, R. G. Hulet, Science 311, 503

(2006)

Authors: Martin W. Zwierlein and Wolfgang Ketterle

Comments: Science, in press

Subj-class: Superconductivity; Strongly Correlated Electrons

\\ ( http://arXiv.org/abs/cond-mat/0603489 , 16kb)

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Paper: cond-mat/0606155

replaced with revised version Mon, 18 Sep 2006 18:18:25 GMT (408kb)

Title: Coherent matter waves emerging from Mott-insulators

Authors: K. Rodriguez, S.R. Manmana, M. Rigol, R.M. Noack and A. Muramatsu

Comments: 20 pages, 11 figures. Published version

Subj-class: Other

Journal-ref: New J. Phys. 8, 169 (2006)

DOI: 10.1088/1367-2630/8/8/169

\\ ( http://arXiv.org/abs/cond-mat/0606155 , 408kb)

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Paper: cond-mat/0609338

replaced with revised version Sun, 17 Sep 2006 09:24:49 GMT (324kb)

Title: Continuous measurements enhanced self-trapping of degenerate ultra-cold

atoms: Nonlinear Quantum Zeno Effect

Authors: WeiDong Li and Jie Liu

Comments: 7 pages, 8 figures

Subj-class: Mesoscopic Systems and Quantum Hall Effect; Other

\\ ( http://arXiv.org/abs/cond-mat/0609338 , 324kb)

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Paper: cond-mat/0609340

replaced with revised version Sun, 17 Sep 2006 09:13:40 GMT (114kb)

Title: The stationary solutions of G-P equations in double square well

Authors: Weidong Li

Comments: 7 pages, 4 figures. accepted by Phys. Rev. A. (2006)

Subj-class: Mesoscopic Systems and Quantum Hall Effect

\\ ( http://arXiv.org/abs/cond-mat/0609340 , 114kb)

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Paper: quant-ph/0609119

Date: Fri, 15 Sep 2006 22:19:50 GMT (76kb)

Title: Ultracold bosons and entanglement in the tilted double-well

Authors: D. R. Dounas-Frazer, A. M. Hermundstad, and L. D. Carr

Comments: 4 pages, 4 figures

\\

Ultracold bosons in a two-well potential are investigated via a four-mode

model. It is shown that, for typical experimental parameters, the lowest lying

entangled eigenstates cannot be described by the usual two-mode model that

allows particles to occupy only the lowest level in each well. A small

potential difference between the wells, or tilt, will cause the decoherence of

entangled eigenstates. However, entangled states reappear when the tilt is

equal to an integer multiple of twice the interaction strength.

\\ ( http://arXiv.org/abs/quant-ph/0609119 , 76kb)

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Paper: quant-ph/0609131

Date: Mon, 18 Sep 2006 11:06:03 GMT (106kb)

Title: Converting the entanglement between modes of massive particles into

Bell-testable forms

Authors: S. Ashhab, Koji Maruyama, Franco Nori

Comments: 7 pages (two-column), 2 figures

\\

We consider the question of whether it is possible to convert the

entanglement between spatially separated modes of massive particles into a form

that would allow the experimental observation of nonlocal quantum correlations.

In the simplest setups analogous to optics experiments, that conversion is

prohibited by fundamental conservation laws. However, we show that using

auxiliary particles, that goal can be achieved with varying levels of success,

depending on the nature and number of auxiliary particles used. In particular,

we find that an auxiliary Bose-Einstein condensate allows the conversion

arbitrarily many times with a small error that depends only on the initial

state of the condensate.

\\ ( http://arXiv.org/abs/quant-ph/0609131 , 106kb)

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Paper: quant-ph/0609133

Date: Mon, 18 Sep 2006 14:29:50 GMT (112kb)

Title: Spontaneous emergence of angular momentum Josephson oscillations in

coupled annular Bose-Einstein condensates

Authors: Igor Lesanovsky and Wolf von Klitzing

\\

We investigate the nonlinear dynamics of two coupled annular Bose-Einstein

condensates (BECs). For certain values of the coupling strength the nonrotating

ground state is unstable with respect to fluctuations in the higher angular

momentum modes. The two branched Bogoliubov spectrum exhibits distinct regions

of instability enabling one to selectively occupy certain angular momentum

modes. For sufficiently long evolution times angular momentum Josephson

oscillations spontaneously appear, breaking the initial chiral symmetry of the

BECs.

\\ ( http://arXiv.org/abs/quant-ph/0609133 , 112kb)

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Paper: quant-ph/0609134

Date: Mon, 18 Sep 2006 16:35:55 GMT (248kb)

Title: Ultrafast Quantum State Control of a Single Trapped Neutral Atom

Authors: Matthew P. A. Jones (LCFIO), Jerome Beugnon (LCFIO), Alpha Ga\"{e}tan

(LCFIO), Junxiang Zhang (LCFIO), Gaetan Messin (LCFIO), Antoine Browaeys

(LCFIO), Philippe Grangier (LCFIO)

Proxy: ccsd ccsd-00096007

\\

We demonstrate the initialisation, read-out and high-speed manipulation of a

qubit stored in a single 87 Rb atom trapped in a submicron-size optical

tweezer. Single qubit rotations are performed on a sub-100 ns time scale using

two-photon Raman transitions. Using the ``spin-echo'' technique, we measure an

irreversible dephasing time of 34 ms. The read-out of the single atom qubit is

at the quantum projection noise limit when averaging up to 1000 individual

events.

\\ ( http://arXiv.org/abs/quant-ph/0609134 , 248kb)

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Paper: quant-ph/0607175

replaced with revised version Sun, 17 Sep 2006 17:54:01 GMT (42kb)

Title: Universal quantum computation in deocoherence-free subspace with neutral

atoms

Authors: P. Xue, and Y.F. Xiao

Comments: 4 pages,2 figures. Final version as published in PRL

\\ ( http://arXiv.org/abs/quant-ph/0607175 , 42kb)

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Paper: physics/0609145

Date: Sat, 16 Sep 2006 13:56:53 GMT (70kb)

Title: Optical Feshbach resonances of Alkaline-Earth atoms in a 1D or 2D

optical lattice

Authors: Pascal Naidon and Paul S. Julienne

Comments: 12 pages, 4 figures

Subj-class: Atomic Physics

\\

Motivated by a recent experiment by Zelevinsky et al. [Phys. Rev. Lett. 96,

203201], we present the theory for photoassociation and optical Feshbach

resonances of atoms confined in a tight one-dimensional (1D) or two-dimensional

(2D) optical lattice. In the case of an alkaline-earth intercombination

resonance, the narrow natural width of the line makes it possible to observe

clear manifestations of the dimensionality, as well as some sensitivity to the

scattering length of the atoms. Among possible applications, a 2D lattice may

be used to increase the spectroscopic resolution by about one order of

magnitude. Furthermore, a 1D lattice induces a shift which provides a new way

of determining the strength of a resonance by spectroscopic measurements.

\\ ( http://arXiv.org/abs/physics/0609145 , 70kb)

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Paper: physics/0609154

Date: Mon, 18 Sep 2006 18:33:49 GMT (120kb)

Title: Physics in Films: An Assessment

Authors: C. Efthimiou, R. Llewellyn, D. Maronde, T. Winningham

Subj-class: Physics Education

\\

Physics in Films is an alternative version of the physical science course

offered to non-science majors at the University of Central Florida. The course

uses the popularity of Hollywood films to generate interest in science and to

engage students that have traditionally been resistant to taking science

courses. Scenes that lead to teachable science moments are identified in films

and then used in class to concretize abstract physical concepts. With the wide

variety of movies available, different "flavors" of the course, each

specializing in a certain genre of film, have been created. This creates an

audience of students with a high level of interest in the teaching tool and

helps enhance their learning experience. In addition to the films, the course

uses electronic student response systems to increase class participation.

Although the course was first developed during the academic year 2002-2003, we

continue to develop and assess it. After a brief outline of the motivation for

the development of the course, we will discuss the different versions of the

course and the teaching techniques used, including the use of the student

response systems, and present data on the performance of the students in the

course. Moreover, we will present feedback on the course acquired from video

interviews with participating students.

\\ ( http://arXiv.org/abs/physics/0609154 , 120kb)

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Paper: cond-mat/0609445

Date: Tue, 19 Sep 2006 05:02:46 GMT (48kb)

Title: Superfluid density and condensate fraction in the BCS-BEC crossover

regime at finite temperatures

Authors: N. Fukushima, Y. Ohashi, E. Taylor, and A. Griffin

Comments: 32 pages, 12 figures

Subj-class: Materials Science

\\

The superfluid density is a fundamental quantity describing the response to a

rotation as well as in two-fluid collisional hydrodynamics. We present

extensive calculations of the superfluid density \rho_s in the BCS-BEC

crossover regime of a uniform superfluid Fermi gas at finite temperatures. We

include strong-coupling or fluctuation effects on these quantities within a

Gaussian approximation. We also incorporate the same fluctuation effects into

the BCS single-particle excitations described by the superfluid order parameter

\Delta and Fermi chemical potential \mu, using the Nozi\`eres and Schmitt-Rink

(NSR) approximation. This treatment is shown to be necessary for consistent

treatment of \rho_s over the entire BCS-BEC crossover. We also calculate the

condensate fraction N_c as a function of the temperature, a quantity which is

quite different from the superfluid density \rho_s. We show that the mean-field

expression for the condensate fraction N_c is a good approximation even in the

strong-coupling BEC regime. Our numerical results show how \rho_s and N_c

depend on temperature, from the weak-coupling BCS region to the BEC region of

tightly-bound Cooper pair molecules. In a companion paper by the authors

(cond-mat/0609187), we derive an equivalent expression for \rho_s from the

thermodynamic potential, which exhibits the role of the pairing fluctuations in

a more explicit manner.

\\ ( http://arXiv.org/abs/cond-mat/0609445 , 48kb)

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Paper: cond-mat/0609468

Date: Tue, 19 Sep 2006 14:54:45 GMT (196kb)

Title: Solitons in a trapped spin-1 atomic condensate

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

Comments: 8 pages, 8 eps figures

Subj-class: Other

\\

We numerically investigate a particular type of spin solitons inside a

trapped atomic spin-1 Bose-Einstein condensate (BEC) with ferromagnetic

interactions. Within the mean field theory approximation, our study of the

solitonic dynamics shows that the solitonic wave function, its center of mass

motion, and the local spin evolutions are stable and are intimately related to

the domain structures studied recently in spin-1 $^{87}$Rb condensates. We

discuss a rotating reference frame wherein the dynamics of the solitonic local

spatial spin distribution become time independent.

\\ ( http://arXiv.org/abs/cond-mat/0609468 , 196kb)

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Paper: cond-mat/0609472

Date: Tue, 19 Sep 2006 15:32:49 GMT (571kb)

Title: Quantum Hall-like effect for cold atoms in non-Abelian gauge fields

Authors: N. Goldman and P. Gaspard

Comments: 4 pages, 2 figures

Subj-class: Mesoscopic Systems and Quantum Hall Effect

\\

We show the quantization of the Hall-like transverse conductivity of

fermionic cold atoms in the presence of a non-Abelian gauge field. This

quantization is obtained by relating the transverse conductivity to topological

invariants defined in the non-Abelian framework. The different integer values

of this conductivity are explicitly computed for a specific non-Abelian system

which leads to a fractal phase diagram.

\\ ( http://arXiv.org/abs/cond-mat/0609472 , 571kb)

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Paper: cond-mat/0609474

Date: Tue, 19 Sep 2006 17:01:06 GMT (13kb)

Title: Dipolar effect in coherent spin mixing of two atoms in a single optical

lattice site

Authors: B. Sun, W. X. Zhang, S. Yi, M. S. Chapman, L. You

Comments: 4 pages, 3 color eps figures, to appear in Phys. Rev. Lett

Subj-class: Other

\\

We show that atomic dipolar effects are detectable in the system that

recently demonstrated two-atom coherent spin dynamics within individual lattice

sites of a Mott state. Based on a two-state approximation for the two-atom

internal states and relying on a variational approach, we have estimated the

spin dipolar effect. Despite the absolute weakness of the dipole-dipole

interaction, it is shown that it leads to experimentally observable effects in

the spin mixing dynamics.

\\ ( http://arXiv.org/abs/cond-mat/0609474 , 13kb)

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Paper: cond-mat/0512517

replaced with revised version Tue, 19 Sep 2006 00:53:47 GMT (127kb)

Title: Dynamical mean-field equations for strongly interacting fermionic atoms

in a potential trap

Authors: W. Yi and L.-M. Duan

Comments: replaced with the published version

Subj-class: Other

Journal-ref: Europhys. Lett. 75(6), 854 (2006)

DOI: 10.1209/epl/i2006-10210-x

\\ ( http://arXiv.org/abs/cond-mat/0512517 , 127kb)

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Paper: cond-mat/0601416

replaced with revised version Mon, 18 Sep 2006 21:31:47 GMT (11kb)

Title: Unconventional strongly interacting Bose-Einstein condensates in optical

lattices

Authors: A. B. Kuklov

Comments: Replaced with revised version. References are added

Subj-class: Other

Journal-ref: PRL 97, 110405 (2006)

\\ ( http://arXiv.org/abs/cond-mat/0601416 , 11kb)

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Paper: cond-mat/0605440

replaced with revised version Mon, 18 Sep 2006 20:04:15 GMT (441kb)

Title: Detecting the breached pair phase in a polarized ultracold Fermi gas

Authors: W. Yi and L.-M. Duan

Comments: 4 pages, 3 figures, replaced with the published version

Subj-class: Other

Journal-ref: Phys. Rev. Lett. 97, 120401 (2006)

DOI: 10.1103/PhysRevLett.97.120401

\\ ( http://arXiv.org/abs/cond-mat/0605440 , 441kb)

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Paper: cond-mat/0606470

replaced with revised version Tue, 19 Sep 2006 19:00:11 GMT (46kb)

Title: BCS-BEC crossover on the two-dimensional honeycomb lattice

Authors: Erhai Zhao, Arun Paramekanti (University of Toronto)

Comments: Significantly revised - added sections on the Fermi surface

evolution, corrected error in superfluid density, added possible implications

for high Tc cuprates (nodal metal, quantum criticality)

Subj-class: Superconductivity; Strongly Correlated Electrons

\\ ( http://arXiv.org/abs/cond-mat/0606470 , 46kb)

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Paper (*cross-listing*): math.DS/0405112

replaced with revised version Mon, 18 Sep 2006 21:47:02 GMT (543kb)

Title: Quasiperiodic Dynamics in Bose-Einstein Condensates in Periodic Lattices

and Superlattices

Authors: Martijn van Noort, Mason A. Porter, Yingfei Yi, and Shui-Nee Chow

Comments: 29 pages, 6 figures (several with multiple parts; higher-quality

versions of some of them available at

http://www.its.caltech.edu/~mason/papers), to appear very soon in Journal of

Nonlinear Science

Subj-class: Dynamical Systems; Chaotic Dynamics; Soft Condensed Matter; Atomic

Physics

MSC-class: MSC: 37J40, 70H99, 37N20; PACS: 05.45.-a, 03.75.Lm, 05.30.Jp,

05.45.Ac, 03.75.Nt

\\ ( http://arXiv.org/abs/math/0405112 , 543kb)

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Paper (*cross-listing*): nlin.PS/0507025

replaced with revised version Mon, 18 Sep 2006 22:19:03 GMT (179kb)

Title: Feshbach Resonance Management of Bose-Einstein Condensates in Optical

Lattices

Authors: Mason A. Porter, Marina Chugunova, and Dmitry E. Pelinovsky

Comments: 8 pages, 4 figures (1 with six parts, 3 with two parts)

Subj-class: Pattern Formation and Solitons; Other; Atomic Physics; Dynamical

Systems

\\ ( http://arXiv.org/abs/nlin/0507025 , 179kb)

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Paper: quant-ph/0609139

Date: Mon, 18 Sep 2006 23:28:46 GMT (83kb)

Title: Gravitationally Induced Decoherence of Optical Entanglement

Authors: T. C. Ralph, G. J. Milburn, T. Downes

\\

We propose an experiment in which an entangled pair of optical pulses are

propagated through non-uniform gravitational fields. A field operator

calculation of this situation predicts decoherence of the optical entanglement

under experimentally realistic conditions.

\\ ( http://arXiv.org/abs/quant-ph/0609139 , 83kb)

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Paper: cond-mat/0609484

Date: Tue, 19 Sep 2006 20:12:47 GMT (233kb)

Title: Lowest Landau-level description of a Bose-Einstein condensate in a

rapidly rotating anisotropic trap

Authors: Alexander L. Fetter

Comments: 13 pages, 1 figure

Subj-class: Statistical Mechanics

\\

A rapidly rotating Bose-Einstein condensate in a symmetric two-dimensional

trap can be described with the lowest Landau-level set of states. In this case,

the condensate wave function psi(x,y) is a Gaussian function of r^2 = x^2 +

y^2, multiplied by an analytic function P(z) of the single complex variable z=

x+ i y; the zeros of P(z) denote the positions of the vortices. Here, a similar

description is used for a rapidly rotating anisotropic two-dimensional trap

with arbitrary anisotropy (omega_x/omega_y le 1). The corresponding condensate

wave function psi(x,y) has the form of a complex anisotropic Gaussian with a

phase proportional to xy, multiplied by an analytic function P(zeta), where

zeta is proportional to x + i beta_- y and 0 le beta_- le 1 is a real parameter

that depends on the trap anisotropy and the rotation frequency. The zeros of

P(zeta) again fix the locations of the vortices. Within the set of lowest

Landau-level states at zero temperature, an anisotropic parabolic density

profile provides an absolute minimum for the energy, with the vortex density

decreasing slowly and anisotropically away from the trap center.

\\ ( http://arXiv.org/abs/cond-mat/0609484 , 233kb)

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Paper: cond-mat/0510436

replaced with revised version Wed, 20 Sep 2006 15:29:40 GMT (76kb)

Title: The groundstate of an interacting Bose gas in a harmonic trap -- a

simple renormalization method

Authors: Roman Werpachowski and Jerzy Kijowski

Comments: RevTex 4, 7 figures

Subj-class: Statistical Mechanics

\\ ( http://arXiv.org/abs/cond-mat/0510436 , 76kb)

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Paper: cond-mat/0605085

replaced with revised version Wed, 20 Sep 2006 13:54:02 GMT (38kb)

Title: Anomalous specific heat jump in a two-component ultracold Fermi gas

Authors: Armen Sedrakian, Herbert M\"uther, Artur Polls

Comments: 4 pages, 3 figures. v2 includes a discussion of instabilities; v3:

final version to appear in PRL

Subj-class: Superconductivity; Statistical Mechanics

\\ ( http://arXiv.org/abs/cond-mat/0605085 , 38kb)

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Paper: cond-mat/0607334

replaced with revised version Wed, 20 Sep 2006 13:52:24 GMT (63kb)

Title: Bragg Spectroscopy of Cold Atomic Fermi Gases

Authors: G. M. Bruun, Gordon Baym

Comments: 8 pages, 9 figures. Typos corrected. Reference updated

Subj-class: Superconductivity

\\ ( http://arXiv.org/abs/cond-mat/0607334 , 63kb)

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Paper: quant-ph/0609150

Date: Tue, 19 Sep 2006 20:17:30 GMT (360kb)

Title: Influence of a tight isotropic harmonic trap on photoassociation in

ultracold homonuclear alkali gases

Authors: Sergey Grishkevich and Alejandro Saenz

Comments: 19 pages, 17 figures

\\

The influence of a tight isotropic harmonic trap on photoassociation of two

ultracold alkali atoms forming a homonuclear diatomic is investigated using

realistic atomic interaction potentials. Confinement of the initial atom pair

due to the trap leads to a uniform strong enhancement of the photoassociation

rate to most, but also to a strongly suppressed rate for some final states.

Thus tighter traps do not necessarily enhance the photoassociation rate. A

further massive enhancement of the rate is found for strong interatomic

interaction potentials. The details of this interaction play a minor role,

except for large repulsive interactions for which a sharp window occurs in the

photoassociation spectrum as is known from the trap-free case. A comparison

with simplified models describing the atomic interaction like the

pseudopotential approximation shows that they often provide reasonable

estimates for the trap-induced enhancement of the photoassociation rate even if

the predicted rates can be completely erroneous.

\\ ( http://arXiv.org/abs/quant-ph/0609150 , 360kb)

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Paper: physics/0609166

Date: Wed, 20 Sep 2006 09:18:59 GMT (164kb)

Title: Experimental study of laser detected magnetic resonance based on atomic

alignment

Authors: Gianni Di Domenico, Georg Bison, Stephan Groeger, Paul Knowles,

Anatoly S. Pazgalev, Martin Rebetez, Herve Saudan, Antoine Weis

Comments: 8 pages, 9 figures. Submitted to Phys. Rev. A. Related to

physics/0605234

Subj-class: Atomic Physics

\\

We present an experimental study of the spectra produced by

optical/radio-frequency double resonance in which resonant linearly polarized

laser light is used in the optical pumping and detection processes. We show

that the experimental spectra obtained for cesium are in excellent agreement

with a very general theoretical model developed in our group and we investigate

the limitations of this model. Finally, the results are discussed in view of

their use in the study of relaxation processes in aligned alkali vapors.

\\ ( http://arXiv.org/abs/physics/0609166 , 164kb)

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Paper: cond-mat/0609529

Date: Wed, 20 Sep 2006 21:59:26 GMT (307kb)

Title: Bose-Einstein Condensation and Kinetic energy of liquid $^3$He-$^4$He

Mixtures

Authors: S.O. Diallo, J.V. Pearce, R.T. Azuah, F. Albergamo and H.R. Glyde

Subj-class: Statistical Mechanics; Superconductivity

\\

We present neutron scattering measurements of the momentum distribution of

liquid ${^3}$He-${^4}$He mixtures. The experiments were performed at

wavevectors $Q$, 26 $\leq$ $Q$ $\leq$ 29 {\AA$^{-1}$}, on the MARI

time-of-flight spectrometer at the ISIS Facility, Rutherford Appleton

Laboratory, a spallation neutron source. Mixtures with $^3$He concentrations

$x$ between 0 and 20% were investigated both in the superfluid and normal

phases. From the data, we extract the Bose-Einstein condensate fraction $n_0$

and the momentum distributions of $^3$He and $^4$He atoms. We find that $n_0$

increases somewhat above the pure $^4$He value when $^3$He is added; e.g from

$n_0=(7.25\pm0.75)%$ at $x=$ 0 to $(11\pm3)%$ at $x=$ 15-20%. This agrees with

predictions but is less than the only previous measurement. We find a $^4$He

kinetic energy $K_4$ for pure $^4$He that agrees with previous determinations.

$K_4$ decreases somewhat with increasing $^3$He concentration, less than

observed previously and found in early calculations but in agreement with a

more recent Monte Carlo calculation. The $^3$He response is not well reproduced

by a Fermi gas momentum distribution, $n(\bf{k})$. Rather an $n(\bf{k})$ having

a small step height at the Fermi surface and a substantial high momentum tail

characteristic of a strongly interacting Fermi liquid provides a good fit. This

$n(\bf{k})$ is consistent with calculated $n(\bf{k})$. Thus agreement between

theory and experiment is obtained comparing $n(\bf{k})$ in contrast to earlier

findings based on comparing calculated and observed $^3$He kinetic energies.

\\ ( http://arXiv.org/abs/cond-mat/0609529 , 307kb)

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Paper: cond-mat/0609531

Date: Wed, 20 Sep 2006 22:15:23 GMT (18kb)

Title: Detecting multi-atomic composite states in optical lattices

Authors: Anatoly Kuklov and Henning Moritz

Comments: 9 revtex pages

Subj-class: Other

\\

We propose and discuss methods for detecting quasi-molecular complexes which

are expected to form in strongly interacting optical lattice systems.

Particular emphasis is placed on the detection of composite fermions forming in

Bose-Fermi mixtures. We argue that, as an indirect indication of the composite

fermions and a generic consequence of strong interactions, periodic

correlations must appear in the atom shot noise of bosonic absorption images,

similar to the bosonic Mott insulator [S. F\"olling, et al., Nature {\bf 434},

481 (2005)]. The composites can also be detected directly and their

quasi-momentum distribution measured. This method -- an extension of the

technique of noise correlation interferometry [E. Altman et al., Phys. Rev. A

{\bf 79}, 013603 (2004)] -- relies on measuring higher order correlations

between the bosonic and fermionic shot noise in the absorption images. However,

it fails for complexes consisting of more than three atoms.

\\ ( http://arXiv.org/abs/cond-mat/0609531 , 18kb)

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Paper: cond-mat/0609535

Date: Thu, 21 Sep 2006 06:35:46 GMT (81kb)

Title: Many-body quantum ratchet in a Bose-Einstein condensate

Authors: Dario Poletti, Giuliano Benenti, Giulio Casati and Baowen Li

Comments: 4 pages, 4 figures

Subj-class: Other

\\

We study the dynamics of a dilute Bose-Einstein condensate confined in a

toroidal trap and exposed to a pair of periodically flashed optical lattices.

We first prove that in the noninteracting case this system can present a

quantum symmetry which forbids the ratchet effect classically expected. We then

show how many-body atom-atom interactions, treated within the mean-field

approximation, can break this quantum symmetry, thus generating directed

transport.

\\ ( http://arXiv.org/abs/cond-mat/0609535 , 81kb)

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Paper: cond-mat/0609553

Date: Thu, 21 Sep 2006 17:53:31 GMT (9kb)

Title: On 1+1 Dimensional Galilean Supersymmetry in Ultracold Quantum Gases

Authors: G.S.Lozano, O.Piguet, F.A.Schaposnik, L. Sourrouille

Comments: 12 pages

Subj-class: Other

\\

We discuss a 1+1 dimensional Galilean invariant model recently introduced in

connection with ultracold quantum gases. After showing its relation to a

nonrelativistic 2+1 Chern-Simons matter system, we identify the generators of

the supersymmetry and its relation with the existence of self-dual equations

\\ ( http://arXiv.org/abs/cond-mat/0609553 , 9kb)

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Paper: quant-ph/0609163

Date: Thu, 21 Sep 2006 15:01:43 GMT (49kb)

Title: Quantum mechanics: Myths and facts

Authors: H. Nikolic

Comments: 28 two-column pages, pedagogic review

\\

A common understanding of quantum mechanics (QM) among students and practical

users is often plagued by a number of "myths", that is, widely accepted claims

on which there is not really a general consensus among experts in foundations

of QM. These myths include wave-particle duality, time-energy uncertainty

relation, fundamental randomness, the absence of measurement-independent

reality, locality of QM, nonlocality of QM, the existence of well-defined

relativistic QM, the claims that quantum field theory (QFT) solves the problems

of relativistic QM or that QFT is a theory of particles, as well as myths on

black-hole entropy. The fact is that the existence of various theoretical and

interpretational ambiguities underlying these myths does not yet allow us to

accept them as proven facts. I review the main arguments and counterarguments

lying behind these myths and conclude that QM is still a

not-yet-completely-understood theory open to further fundamental research.

\\ ( http://arXiv.org/abs/quant-ph/0609163 , 49kb)

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Paper: physics/0609176

Date: Thu, 21 Sep 2006 02:06:35 GMT (29kb)

Title: Precise Numerical Solutions of Potential Problems Using Crank-Nicholson

Method

Authors: Daekyoung Kang and E. Won

Comments: 10 pages, 1 figure. Submitted to Phys. Rev. Lett

Subj-class: Computational Physics; Atomic Physics

\\

A new numerical treatment in the Crank-Nicholson method with the imaginary

time evolution operator is presented in order to solve the Schr\"{o}dinger

equation. The original time evolution technique is extended to a new operator

that provides a systematic way to calculate not only eigenvalues of ground

state but also of excited states. This new method systematically produces

eigenvalues with accuracies of eleven digits with the Cornell potential that

covers non-perturbative regime. An absolute error estimation technique based on

a power counting rule is implemented. This method is examined with exactly

solvable problems and produces the numerical accuracy down to 10$^{-11}$.

\\ ( http://arXiv.org/abs/physics/0609176 , 29kb)

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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 Mon Sep 25 2006 - 10:47:29 EST

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