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

Date: Mon, 3 Apr 2006 11:43:18 +1000 (EST)

Date: Mon, 3 Apr 2006 11:43:18 +1000 (EST)

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

Lots of preprints this week! Instructions on signing up to this email can be

found here:

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

If anyone out there is looking for an experimental postdoctoral position in

quantum atom optics in a warm sunny climate, you might like to look at this:

http://www.seek.com.au/showjob.asp?jobid=6592835

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/ ------------------------------------------------------------------------- ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603639 Date: Fri, 24 Mar 2006 01:10:45 GMT (10kb) Title: Molecular Bose-Einstein condensates, resonance chemistry, and enhancement of weak interactions Authors: V.V. Flambaum, J.S.M. Ginges Comments: 5 pages Subj-class: Other \\ With the creation of atomic and molecular Bose-Einstein condensates (BECs), a new type of chemistry - "resonance" chemistry - emerges: chemical reactions can occur when the energy of colliding atoms/molecules matches a bound state of the combined molecule (Feshbach resonance). This chemistry is rather similar to reactions that take place in nuclei at low energies. In this paper we suggest some problems for future experimental and theoretical work related to the resonance chemistry of molecular BECs. Molecular BECs are particularly interesting because in this system collisions and chemical reactions are extremely sensitive to weak fields. This sensitivity arises due to the high density of narrow compound resonances and the macroscopic number of molecules with kinetic energy E=0 (more accurately, in the ground state of a mean-field potential). The high sensitivity to the magnetic field may be used to measure the distribution of energy intervals, widths, and magnetic moments of compound resonances and study the onset of quantum chaos. A difference in the production rate of right-handed and left-handed chiral molecules may be produced by external electric and magnetic fields and the finite width of the resonance. The same effect may be produced by the parity-violating energy difference in chiral molecules. \\ ( http://arXiv.org/abs/cond-mat/0603639 , 10kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603643 Date: Fri, 24 Mar 2006 06:46:59 GMT (61kb) Title: The 1D interacting anyon gas: low-energy properties and Haldane exclusion statistics Authors: M.T. Batchelor, X.-W. Guan and N. Oelkers Comments: 4 pages, 2 figures Subj-class: Statistical Mechanics \\ The low energy properties of the one-dimensional anyon gas with $\delta$-function interaction are discussed in the context of its Bethe ansatz solution. It is found that the anyonic statistical parameter and the dynamical coupling constant induce Haldane exclusion statistics interpolating between bosons and fermions. Moreover, the anyonic parameter may trigger statistics beyond Fermi statistics for which the Haldane exclusion parameter $\alpha$ is greater than one. The model is discussed in detail in the Tonks-Girardeau and the weak coupling limits. The results support the universal role of $\alpha$ in the dispersion relations. \\ ( http://arXiv.org/abs/cond-mat/0603643 , 61kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603654 Date: Fri, 24 Mar 2006 14:10:55 GMT (449kb) Title: Dynamical density-density correlations in the one-dimensional Bose gas Authors: J.-S. Caux and P. Calabrese Comments: 4 pages, 3 figures Subj-class: Statistical Mechanics \\ The zero-temperature dynamical structure factor of the one-dimensional Bose gas with delta-function interaction (Lieb-Liniger model) is computed using a hybrid theoretical/numerical method based on the exact Bethe Ansatz solution, which allows to interpolate continuously between the weakly-coupled Thomas-Fermi and strongly-coupled Tonks-Girardeau regimes. The results should be experimentally accessible with Bragg spectroscopy. \\ ( http://arXiv.org/abs/cond-mat/0603654 , 449kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603655 Date: Fri, 24 Mar 2006 14:18:28 GMT (565kb) Title: Onset of a Bose-Glass of ultracold atoms in a disordered crystal of light Authors: L. Fallani, J. E. Lye, V. Guarrera, C. Fort, M. Inguscio Comments: 8 pages, 6 figures Subj-class: Other \\ Disorder is ubiquitous in nature, manifesting itself in many key physical and biological processes. It plays a fundamental role in the physics of conduction in metals and in the superfluid-insulator transition occurring in many condensed-matter systems. Ultracold atoms in optical potentials can be used as "quantum simulators" to model such disordered systems, taking advantage of the possibility to accurately control the kind and amount of disorder. Starting from a Mott Insulator state, we use a bichromatic optical lattice to add controlled disorder to an ideal optical crystal where bosonic atoms are pinned by repulsive interactions. Increasing disorder, we observe the onset of a gapless insulating Bose-Glass phase induced by the cooperation of interactions and disorder. This observation paves the way to the investigation of new strongly correlated disordered phases of broad interest even beyond the realm of physics. \\ ( http://arXiv.org/abs/cond-mat/0603655 , 565kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603665 Date: Fri, 24 Mar 2006 17:16:38 GMT (1870kb) Title: Pseudofermion scattering theory Authors: J. M. P. Carmelo, D. Bozi, and P. D. Sacramento Comments: 36 pages, 30 figures Subj-class: Strongly Correlated Electrons \\ In this paper we study the scattering theory associated with the pseudofermion dynamical theory for the Hubbard chain. In terms of pseudofermions the spectral properties are controlled by zero-momentum forward scattering only. The pseudofermion $S$ matrix is expressed as a commutative product of $S$ matrices, each corresponding to an elementary two-pseudofermion scattering event. This commutative factorization is stronger than the usual factorization associated with Yang-Baxter Equation for the original spin 1/2 electron bare $S$ matrix. Our results reveal the scattering mechanisms which control the exotic finite-energy spectral properties of the low-dimensional complex materials and correlated systems of cold fermionic atoms on an optical lattice. Importantly, the exotic scatterers and scattering centers predicted by the theory were observed by angle-resolved photoelectron spectroscopy in low-dimensional organic metals. \\ ( http://arXiv.org/abs/cond-mat/0603665 , 1870kb) ------------------------------------------------------------------------------ \\ Paper (*cross-listing*): gr-qc/0603093 Date: Thu, 23 Mar 2006 14:36:20 GMT (469kb) Title: Black-Hole and White-Hole Horizons in Superfluids Authors: G.E. Volovik Comments: 14 pages, 5 Figures, draft for proceedings of the workshop "Universal features in turbulence: from quantum to cosmological scales", December 2005, Warwick Subj-class: General Relativity and Quantum Cosmology; Fluid Dynamics; Soft Condensed Matter \\ Ripplons -- gravity-capillary waves on the free surface of a liquid or at the interfaces between two superfluids -- are the most favourable excitations for simulation of the general-relativistic effects related to horizons and ergoregions. The white-hole horizon for the ``relativistic'' ripplons at the surface of the shallow liquid is easily simulated using the kitchen-bath hydraulic jump. The same white-hole horizon is observed in quantum liquid -- superfluid 4He. The ergoregion for the ``non-relativistic'' ripplons is generated in the experiments with two sliding 3He superfluids. The common property experienced by all these ripplons is the Miles instability inside the ergoregion or horizon. Because of the universality of the Miles instability, one may expect that it could take place inside the horizon of the astrophysical black holes, if there is a preferred reference frame which comes from the trans-Planckian physics. If this is the case, the black hole would evapotate much faster than due to the Hawking radiation. Hawking radiation from the artificial black hole in terms of the quantum tunneling of phonons and ripplons is also discussed. \\ ( http://arXiv.org/abs/gr-qc/0603093 , 469kb) ------------------------------------------------------------------------------ \\ Paper (*cross-listing*): nlin.PS/0603050 Date: Thu, 23 Mar 2006 12:08:46 GMT (267kb) Title: Discrete Solitons in the Salerno Model with competing nonlinearities Authors: J. Gomez-Gardenes, B.A. Malomed, L.M. Floria, and A.R. Bishop Comments: 8 pages, 10 figures Subj-class: Pattern Formation and Solitons; Soft Condensed Matter Journal-ref: Physical Review E 73 036608 (2006) DOI: 10.1103/PhysRevE.73.036608 \\ We consider a lattice equation (Salerno model) combining onsite self-focusing and intersite self-defocusing cubic terms, which may describe a Bose-Einstein condensate of dipolar atoms trapped in a strong periodic potential. In the continuum approximation, the model gives rise to solitons in a finite band of frequencies, with sechlike solitons near one edge, and an exact peakon solution at the other. A similar family of solitons is found in the discrete system, including a peakon; beyond the peakon, the family continues in the form of cuspons. Stability of the lattice solitons is explored through computation of eigenvalues for small perturbations, and by direct simulations. A small part of the family is unstable (in that case, the discrete solitons transform into robust pulsonic excitations); both peakons and cuspons are stable. The Vakhitov-Kolokolov criterion precisely explains the stability of regular solitons and peakons, but does not apply to cuspons. In-phase and out-of-phase bound states of solitons are also constructed. They exchange their stability at a point where the bound solitons are peakons. Mobile solitons, composed of a moving core and background, exist up to a critical value of the strength of the self-defocusing intersite nonlinearity. Colliding solitons always merge into a single pulse. \\ ( http://arXiv.org/abs/nlin/0603050 , 267kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0512103 replaced with revised version Fri, 24 Mar 2006 14:40:34 GMT (98kb) Title: Superglass Phase of Helium-four Authors: M. Boninsegni, N. Prokof'ev and B. Svistunov Subj-class: Statistical Mechanics Journal-ref: Phys. Rev. Lett. 96, 105301 (2006) \\ ( http://arXiv.org/abs/cond-mat/0512103 , 98kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0601006 replaced with revised version Thu, 23 Mar 2006 23:16:06 GMT (67kb) Title: Trapped Fermions across a Feshbach resonance with population imbalance Authors: W. Yi and L.-M. Duan Comments: 4 pages, 3 figures, replaced with the published version Subj-class: Other Journal-ref: Phys. Rev. A 73, 031604(R) (2006) DOI: 10.1103/PhysRevA.73.031604 \\ ( http://arXiv.org/abs/cond-mat/0601006 , 67kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0602283 replaced with revised version Fri, 24 Mar 2006 17:14:29 GMT (118kb) Title: Time of flight observables and the formation of Mott domains of fermions and bosons on optical lattices Authors: M. Rigol, R. T. Scalettar, P. Sengupta, and G. G. Batrouni Comments: 5 pages, 6 figures, published version Subj-class: Strongly Correlated Electrons; Superconductivity Journal-ref: Phys. Rev. B 73, 121103(R) (2006) DOI: 10.1103/PhysRevB.73.121103 \\ ( http://arXiv.org/abs/cond-mat/0602283 , 118kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603273 replaced with revised version Fri, 24 Mar 2006 11:12:21 GMT (55kb) Title: Ultracold atomic F=2 spinor gas in an optical lattice Authors: L. Zawitkowski, K. Eckert, A. Sanpera, M.Lewenstein Comments: 6 pages, 1 figure; comments on Feshbach resonances and attractive interactions added Subj-class: Other \\ ( http://arXiv.org/abs/cond-mat/0603273 , 55kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603607 replaced with revised version Fri, 24 Mar 2006 05:35:17 GMT (11kb) Title: Enhancement of variation of fundamental constants in ultracold atom and molecule systems near Feshbach resonances Authors: Cheng Chin, V.V. Flambaum Subj-class: Other; Disordered Systems and Neural Networks; Atomic Physics \\ ( http://arXiv.org/abs/cond-mat/0603607 , 11kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603675 Date: Fri, 24 Mar 2006 21:26:29 GMT (465kb) Title: Resonator-Aided Single-Atom Detection on a Microfabricated Chip Authors: Igor Teper, Yu-Ju Lin, Vladan Vuletic Comments: 4.1 pages, 5 figures, and submitted to Physical Review Letters Subj-class: Other \\ We use an optical cavity to detect single atoms magnetically trapped on an atom chip. We implement the detection using both fluorescence into the cavity and reduction in cavity transmission due to the presence of atoms. In fluorescence, we register 2.0(2) photon counts per atom, which allows us to detect single atoms with 75% efficiency in 250 microseconds. In absorption, we measure transmission attenuation of 3.3(3)% per atom, which allows us to count small numbers of atoms with a resolution of about 1 atom. \\ ( http://arXiv.org/abs/cond-mat/0603675 , 465kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603684 Date: Sat, 25 Mar 2006 09:23:15 GMT (103kb) Title: Gauge field in ultra-cold bipartite atoms Authors: H. Wang, W. Wang, and X. X. Yi Comments: 4 pages, 1 figure Subj-class: Other \\ The effects of entanglement and spin-spin collision on the gauge field in ultracold atoms are presented in this paper. Two gauge fields are calculated and discussed. One of the fields comes from space dependent spin-spin collisions in ultra-cold atoms, while another results from the usual Born-Oppenheimer method, which separates the center-of-mass motion from the relative motion in the two-body problem. Adiabatic conditions that lead to the key results of this paper are also presented and discussed. Entanglement shared between the two atoms is shown to affect the atomic motion. In the presence of entanglement, the additional scalar potential disappears, this is different from the case of atoms in separable states. \\ ( http://arXiv.org/abs/cond-mat/0603684 , 103kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603686 Date: Mon, 27 Mar 2006 16:23:11 GMT (29kb) Title: Nonadiabatic production of spinor condensates with a QUIC trap Authors: P. Zhang, Z. Xu and L. You Comments: 6 pages, 2 figures Subj-class: Statistical Mechanics Journal-ref: Phys. Rev. A 73, 013623 (2006) \\ Motivated by the recent experimental observation of multi-component spinor condensates via a time-dependent quadrupole-Ioffe-configuration trap (QUIC trap), we provide a general framework for the investigation of nonadiabatic Landau-Zener dynamics of a hyperfine spin, e.g., from an atomic magnetic dipole moment coupled to a weak time-dependent magnetic (B-) field. The spin flipped population distribution, or the so-called Majorona formula is expressed in terms of system parameters and experimental observables; thus, provides much needed insight into the underlying mechanism for the production of spinor condensates due to nonadiabatic level crossings. \\ ( http://arXiv.org/abs/cond-mat/0603686 , 29kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603699 Date: Mon, 27 Mar 2006 00:07:31 GMT (739kb) Title: Vortex creation during magnetic trap manipulations of spinor Bose-Einstein condensates Authors: A.P. Itin, T. Morishita, M. Satoh, O.I. Tolstikhin, and S. Watanabe Comments: 16 pages, 8 figures (of reduced quality; original figures are available upon request: alx_it_at_yahoo.com) Subj-class: Other \\ We investigate several mechanisms of vortex creation during splitting of a spinor BEC in a magnetic trap controlled by a pair of current carrying wires and bias magnetic fields. Our study is motivated by a recent MIT experiment on splitting BECs with a similar trap, where unexpected fork-like structure appeared in the interference fringes corresponding to interference of two condensates, one with and the other without a singly quantized vortex. It is well known that in a spin-1 BEC in a quadrupole trap a doubly quantized vortex is produced topologically by reversal of bias magnetic field $B_z$. We find that in the magnetic trap considered it is also possible to produce a 4- and 1-quantized vortex in a spin-1 BEC. The latter is possible, for example, during the magnetic field switching-off process. We therefore provide a possible explanation for the unexpected interference patterns in the experiment. We also give an example of the creation of singly quantized vortices due to fast splitting, which is a possible alternative mechanism of the interference pattern. \\ ( http://arXiv.org/abs/cond-mat/0603699 , 739kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603709 Date: Mon, 27 Mar 2006 10:36:51 GMT (138kb) Title: Quantum squeezing by a parametric resonance in a SQUID Authors: T. Ojanen, J. Salo Comments: 8 pages, 11 Figs Subj-class: Mesoscopic Systems and Quantum Hall Effect; Superconductivity \\ We study rotating squeezed quantum states created by a parametric resonance in an open harmonic system. As a specific realization of the phenomenon we study a mesoscopic SQUID loop where the state preparation procedure is simple in principle and feasible with currently available experimental methods. By solving dynamics and calculating spectral properties we show that quantum fluctuations of SQUID observables can be reduced below their groundstate value. The measurement is introduced by coupling the SQUID to a transmission line carrying the radiation to a secondary measurement device. Besides the theoretical interest, our studies are motivated by an opportunity for a practical quantum noise engineering. \\ ( http://arXiv.org/abs/cond-mat/0603709 , 138kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603710 Date: Mon, 27 Mar 2006 10:51:03 GMT (73kb) Title: Regulating entanglement production in multitrap Bose-Einstein condensates Authors: V.I. Yukalov and E.P. Yukalova Comments: Latex file, 3 figures Subj-class: Mesoscopic Systems and Quantum Hall Effect; Statistical Mechanics Journal-ref: Phys. Rev. A 73 (2006) 022335-10 \\ A system of traps is considered, each containing a large number of Bose-condensed atoms. This ensemble of traps is subject to the action of an external modulating field generating nonequilibrium nonground-state condensates. When the frequency of the modulating field is in resonance with the transition frequency between two different topological coherent modes, each trap becomes an analog of a finite-level resonant atom. Similarly to the case of atoms in an electromagnetic resonant field, one can create entanglement between atomic traps subject to a common resonant modulating field generating higher coherent modes in each of the traps. A method is suggested for regulating entanglement production in such a system of multitrap and multimode Bose-Einstein condensates coupled through a common resonant modulating field. Several regimes of evolutional entanglement production, regulated by manipulating the external field, are illustrated by numerical calculations. \\ ( http://arXiv.org/abs/cond-mat/0603710 , 73kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603712 Date: Mon, 27 Mar 2006 12:56:43 GMT (23kb) Title: Effect of superradiance on transport of diffusing photons in cold atomic gases Authors: A. Gero and E. Akkermans Comments: 4 pages and 1 figure Subj-class: Mesoscopic Systems and Quantum Hall Effect Journal-ref: Physical Review Letters 96, 093601 (2006) \\ We show that in atomic gases cooperative effects like superradiance and subradiance lead to a potential between two atoms that decays like $1/r$. In the case of superradiance, this potential is attractive for close enough atoms and can be interpreted as a coherent mesoscopic effect. The contribution of superradiant pairs to multiple scattering properties of a dilute gas, such as photon elastic mean free path and group velocity, is significantly different from that of independent atoms. We discuss the conditions under which these effects may be observed and compare our results to recent experiments on photon transport in cold atomic gases. \\ ( http://arXiv.org/abs/cond-mat/0603712 , 23kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603721 Date: Mon, 27 Mar 2006 19:08:47 GMT (53kb) Title: Spectroscopy of ultracold atoms by periodic lattice modulations Authors: C. Kollath, A. Iucci, T. Giamarchi, W. Hofstetter, U. Schollwoeck Subj-class: Other \\ We present a non-perturbative analysis of a new experimental technique for probing ultracold bosons in an optical lattice by periodic lattice depth modulations. This is done using the time-dependent density-matrix renormalization group method. We find that sharp energy absorption peaks are not unique to the Mott insulating phase at commensurate filling, but also exist for superfluids at incommensurate filling. For strong interactions the peak structure provides an experimental measure of the interaction strength. Moreover, the peak height of the second peak can be employed as a measure of the incommensurability of the system. \\ ( http://arXiv.org/abs/cond-mat/0603721 , 53kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0512010 replaced with revised version Mon, 27 Mar 2006 09:30:33 GMT (422kb) Title: Sound velocity and dimensional crossover in a superfluid Fermi gas in an optical lattice Authors: T. Koponen, J.-P. Martikainen, J. Kinnunen, and P. Torma Comments: 16 pages, 9 figures, replaced with the published version Subj-class: Superconductivity Journal-ref: Phys. Rev. A 73, 033620 (2006) \\ ( http://arXiv.org/abs/cond-mat/0512010 , 422kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0512518 replaced with revised version Fri, 24 Mar 2006 22:54:17 GMT (550kb) Title: Rapid sympathetic cooling to Fermi degeneracy on a chip Authors: S. Aubin, S. Myrskog, M. H. T. Extavour, L. J. LeBlanc, D. McKay, A. Stummer, J. H. Thywissen Comments: 5 pages, 4 figures (v3: new collision data, improved atom number calibration, revised text, improved figures.) Subj-class: Statistical Mechanics \\ ( http://arXiv.org/abs/cond-mat/0512518 , 550kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603513 replaced with revised version Sun, 26 Mar 2006 12:42:01 GMT (70kb) Title: Ultra Cold Atoms in Incommensurate 1D Optical Lattices - an Interacting Aubry-Andre Model Authors: Nir Bar-Gill, Rami Pugatch, Eitan Rowen, Nadav Katz, and Nir Davidson Comments: 5 pages, 4 figures Subj-class: Disordered Systems and Neural Networks \\ ( http://arXiv.org/abs/cond-mat/0603513 , 70kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603571 replaced with revised version Sun, 26 Mar 2006 06:55:04 GMT (85kb) Title: Identifying the Bose glass phase Authors: R. Pugatch, N. Bar-gill, N. Katz, E. Rowen, N. Davidson Comments: 4 pages, 3 figures (corrected bibliography) Subj-class: Soft Condensed Matter; Other \\ ( http://arXiv.org/abs/cond-mat/0603571 , 85kb) ------------------------------------------------------------------------------ \\ Paper: quant-ph/0603229 Date: Sat, 25 Mar 2006 18:44:55 GMT (23kb) Title: Spin Decoherence in Superconducting Atom Chips Authors: Per Kristian Rekdal, Ulrich Hohenester, Bo-Sture K. Skagerstam, Asier Eiguren Comments: 4 pages, 2 figures \\ Using a consistent quantum-mechanical treatment for the electromagnetic radiation, we theoretically investigate the magnetic spin-flip scatterings of a neutral two-level atom trapped in the vicinity of a superconducting body. We derive a simple scaling law for the corresponding spin-flip lifetime for such an atom trapped near a superconducting thick slab. For temperatures below the superconducting transition temperature T_c, the lifetime is found to be enhanced by several orders of magnitude in comparison to the case of a normal conducting slab. At zero temperature the spin-flip lifetime is given by the unbounded free-space value. \\ ( http://arXiv.org/abs/quant-ph/0603229 , 23kb) ------------------------------------------------------------------------------ \\ Paper: quant-ph/0603245 Date: Mon, 27 Mar 2006 18:19:40 GMT (22kb) Title: On the statistics of quantum expectations for systems in thermal equilibrium Authors: Giovanni Jona-Lasinio, Carlo Presilla Comments: 6 pages, 2 figures, contribution to Quantum Jumps Conference \\ The recent remarkable developments in quantum optics, mesoscopic and cold atom physics have given reality to wave functions. It is then interesting to explore the consequences of assuming ensembles over the wave functions simply related to the canonical density matrix. In this note we analyze a previously introduced distribution over wave functions which naturally arises considering the Schroedinger equation as an infinite dimensional dynamical system. In particular, we discuss the low temperature fluctuations of the quantum expectations of coordinates and momenta for a particle in a double well potential. Our results may be of interest in the study of chiral molecules. \\ ( http://arXiv.org/abs/quant-ph/0603245 , 22kb) ------------------------------------------------------------------------------ \\ Paper: physics/0602108 replaced with revised version Mon, 27 Mar 2006 14:40:46 GMT (516kb) Title: All-optical generation and photoassociative probing of sodium Bose-Einstein condensates Authors: R. Dumke, M. Johanning, E. Gomez, J. D. Weinstein, K. M. Jones and P. D. Lett Comments: 8 pages, 10 figures Subj-class: Atomic Physics \\ ( http://arXiv.org/abs/physics/0602108 , 516kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603732 Date: Tue, 28 Mar 2006 01:26:49 GMT (37kb) Title: A basis-set based Fortran program to solve the Gross-Pitaevskii Equation for dilute Bose gases in harmonic and anharmonic traps Authors: Rakesh P. Tiwari and Alok Shukla Comments: 3 figures (included), to appear in Computer Physics Communications Subj-class: Other; Mesoscopic Systems and Quantum Hall Effect \\ Inhomogeneous boson systems, such as the dilute gases of integral spin atoms in low-temperature magnetic traps, are believed to be well described by the Gross-Pitaevskii equation (GPE). GPE is a nonlinear Schroedinger equation which describes the order parameter of such systems at the mean field level. In the present work, we describe a Fortran 90 computer program developed by us, which solves the GPE using a basis set expansion technique. In this technique, the condensate wave function (order parameter) is expanded in terms of the solutions of the simple-harmonic oscillator (SHO) characterizing the atomic trap. Additionally, the same approach is also used to solve the problems in which the trap is weakly anharmonic, and the anharmonic potential can be expressed as a polynomial in the position operators x, y, and z. The resulting eigenvalue problem is solved iteratively using either the self-consistent-field (SCF) approach, or the imaginary time steepest-descent (SD) approach. Our results for harmonic traps are also compared with those published by other authors using different numerical approaches, and excellent agreement is obtained. GPE is also solved for a few anharmonic potentials, and the influence of anharmonicity on the condensate is discussed. Additionally, the notion of Shannon entropy for the condensate wave function is defined and studied as a function of the number of particles in the trap. It is demonstrated numerically that the entropy increases with the particle number in a monotonic way. \\ ( http://arXiv.org/abs/cond-mat/0603732 , 37kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603744 Date: Tue, 28 Mar 2006 08:33:22 GMT (7kb) Title: On the computation of the entropy in the microcanonical ensemble for mean-field-like systems Authors: Alessandro Campa Comments: 9 pages, no figures Subj-class: Statistical Mechanics \\ Two recently proposed expressions for the computation of the entropy in the microcanonical ensemble are compared, and their equivalence is proved. These expressions are valid for a certain class of statistical mechanics systems, that can be called mean-field-like systems. Among these, this work considers only the systems with the most usual hamiltonian structure, given by a kinetic energy term plus interaction terms depending only on the configurational coordinates. \\ ( http://arXiv.org/abs/cond-mat/0603744 , 7kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603747 Date: Tue, 28 Mar 2006 09:23:03 GMT (14kb) Title: Pairing of a harmonically trapped fermionic Tonks-Girardeau gas Authors: A. Minguzzi, M.D. Girardeau Comments: 4 pages, 3 figures, revtex4 Subj-class: Superconductivity \\ The fermionic Tonks-Girardeau (FTG) gas is a one-dimensional spin-polarized Fermi gas with infinitely strong attractive zero-range odd-wave interactions, arising from a confinement-induced resonance reachable via a three-dimensional p-wave Feshbach resonance. We investigate the off-diagonal long-range order (ODLRO) of the FTG gas subjected to a longitudinal harmonic confinement by analyzing the two-particle reduced density matrix for which we derive a closed-form expression. Using a variational approach and numerical diagonalization we find that the largest eigenvalue of the two-body density matrix is of order N/2, where N is the total particle number, and hence a partial ODLRO is present for a FTG gas in the trap. \\ ( http://arXiv.org/abs/cond-mat/0603747 , 14kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603754 Date: Tue, 28 Mar 2006 12:43:54 GMT (17kb) Title: Bose-Einstein Condensation with Entangled Order Parameter Authors: Yu Shi, Qian Niu Comments: 5 pages, 4 figures. Accepted by Phys. Rev. Lett Subj-class: Other \\ We propose a practically accessible non-mean-field ground state of Bose-Einstein condensation (BEC), which occurs in an interspecies two-particle entangled state, and is thus described by an entangled order parameter. A suitably defined entanglement entropy is used as the characterization of the non-mean-field nature, and is found to persist in a wide parameter regime. The interspecies entanglement leads to novel interference terms in the dynamical equations governing the single particle orbital wavefunctions. Experimental feasibility and several methods of probe are discussed. We urge the study of multi-channel scattering between different species of atoms. \\ ( http://arXiv.org/abs/cond-mat/0603754 , 17kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603772 Date: Tue, 28 Mar 2006 20:02:55 GMT (186kb) Title: A condensate interferometer with long coherence time and large arm separation Authors: O. Garcia, B. Deissler, K. J. Hughes, J. M. Reeves and C.A. Sackett Comments: 4 pages, 4 figures Subj-class: Other \\ A condensate Michelson interferometer is demonstrated with coherence times of up to 44 ms and arm separations up to 180 micrometers. This coherence time is four times longer than that of previous condensate interference experiments, and the arm separation is more than an order of magnitude larger than that observed for any previous atom interferometer. The device uses atoms weakly confined in a novel magnetic guide and the atomic motion is controlled using Bragg interactions with an off-resonant standing wave laser beam. \\ ( http://arXiv.org/abs/cond-mat/0603772 , 186kb) ------------------------------------------------------------------------------ \\ Paper: quant-ph/0603255 Date: Tue, 28 Mar 2006 09:53:14 GMT (9kb) Title: Generation of Entanglement from Nonclassical Photon Statistics Authors: Solomon Ivan, N. Mukunda, and R. Simon Comments: 4 pages \\ The ability of the beam splitter to transform nonclassicality beyond squeezing into entanglement is demonstrated. Taking product state of the form $\rho_{{\rm in} =\rho_a\otimes |0>_b {_b}< 0|$ as input, we show that the output of the beam splitter, $\rho_{{\rm out}}$, is entangled whenever the photon number distribution (PND) statistics $\{p(n_a) \}$ associated with the possibly mixed state $\rho_a$ of the a_mode is antibunched, or possesses any other kind of nonclassicality. \\ ( http://arXiv.org/abs/quant-ph/0603255 , 9kb) ------------------------------------------------------------------------------ \\ Paper: quant-ph/0603256 Date: Tue, 28 Mar 2006 18:12:11 GMT (693kb) Title: Quantum Open System Theory: Bipartite Aspects Authors: Ting Yu and J. H. Eberly Comments: 4 pages, 2 figures \\ We demonstrate in straightforward calculations that even under ideally weak noise the relaxation of bipartite open quantum systems contains elements not previously encountered in quantum noise physics and not predicted by the standard theory of quantum open systems. \\ ( http://arXiv.org/abs/quant-ph/0603256 , 693kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603783 Date: Wed, 29 Mar 2006 09:25:06 GMT (362kb) Title: Nature of intrinsic relation between Bloch-band tunneling and modulational instability Authors: V.A. Brazhnyi, V.V. Konotop, and V. Kuzmiak Comments: 5 pages, 3 figures, To appear in Phys.Rev.Lett Subj-class: Soft Condensed Matter \\ On examples of Bose-Einstein condensates embedded in two-dimensional optical lattices we show that in nonlinear periodic systems modulational instability and inter-band tunneling are intrinsically related phenomena. By direct numerical simulations we found that tunneling results in attenuation or enhancement of instability. On the other hand, instability results in asymmetric nonlinear tunneling. The effect strongly depends on the band gap structure and it is especially significant in the case of the resonant tunneling. The symmetry of the coherent structures emerging from the instability reflects the symmetry of both the stable and the unstable states between which the tunneling occurs. Our results provide an evidence of profound effect of the band structure on superfluid-insulator transition. \\ ( http://arXiv.org/abs/cond-mat/0603783 , 362kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603792 Date: Wed, 29 Mar 2006 15:03:44 GMT (546kb) Title: Bose-Einstein condensates in fast rotation Authors: Sabine Stock (LKB - Lhomond), Baptiste Battelier (LKB - Lhomond), Vincent Bretin (LKB - Lhomond), Zoran Hadzibabic (LKB - Lhomond), Jean Dalibard (LKB - Lhomond) Comments: Laser Physics Letters 2, 275 (2005) Proxy: ccsd ccsd-00021948 Subj-class: Mesoscopic Systems and Quantum Hall Effect \\ In this short review we present our recent results concerning the rotation of atomic Bose-Einstein condensates confined in quadratic or quartic potentials, and give an overview of the field. We first describe the procedure used to set an atomic gas in rotation and briefly discuss the physics of condensates containing a single vortex line. We then address the regime of fast rotation in harmonic traps, where the rotation frequency is close to the trapping frequency. In this limit the Landau Level formalism is well suited to describe the system. The problem of the condensation temperature of a fast rotating gas is discussed, as well as the equilibrium shape of the cloud and the structure of the vortex lattice. Finally we review results obtained with a quadratic + quartic potential, which allows to study a regime where the rotation frequency is equal to or larger than the harmonic trapping frequency. \\ ( http://arXiv.org/abs/cond-mat/0603792 , 546kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603793 Date: Wed, 29 Mar 2006 15:03:49 GMT (766kb) Title: Vortex stability in nearly two-dimensional Bose-Einstein condensates with attraction Authors: Dumitru Mihalache, Dumitru Mazilu, Boris A. Malomed, Falk Lederer Comments: 21 pages, 8 figures, to appear in Physical Review A Subj-class: Other \\ We perform accurate investigation of stability of localized vortices in an effectively two-dimensional ("pancake-shaped") trapped BEC with negative scattering length. The analysis combines computation of the stability eigenvalues and direct simulations. The states with vorticity S=1 are stable in a third of their existence region, $0<N<(1/3)N_{\max}^{(S=1)}$, where $N$ is the number of atoms, and $N_{\max}^{(S=1)}$ is the corresponding collapse threshold. Stable vortices easily self-trap from arbitrary initial configurations with embedded vorticity. In an adjacent interval, $(1/3)N_{\max }^{(S=1)}<N<$ $\allowbreak 0.43N_{\max}^{(S=1)}$, the unstable vortex periodically splits in two fragments and recombines. At $N>$ $\allowbreak 0.43N_{\max}^{(S=1)}$, the fragments do not recombine, as each one collapses by itself. The results are compared with those in the full 3D Gross-Pitaevskii equation. In a moderately anisotropic 3D configuration, with the aspect ratio $\sqrt{10}$, the stability interval of the S=1 vortices occupies $\approx 40%$ of their existence region, hence the 2D limit provides for a reasonable approximation in this case. For the isotropic 3D configuration, the stability interval expands to 65% of the existence domain. Overall, the vorticity heightens the actual collapse threshold by a factor of up to 2. All vortices with $S\geq 2$ are unstable. \\ ( http://arXiv.org/abs/cond-mat/0603793 , 766kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0408491 replaced with revised version Tue, 28 Mar 2006 21:23:29 GMT (59kb) Title: Vortices in attractive Bose-Einstein condensates in two dimensions Authors: L. D. Carr and Charles W. Clark Comments: 4 pages, 3 figures Subj-class: Other; Pattern Formation and Solitons \\ ( http://arXiv.org/abs/cond-mat/0408491 , 59kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0509241 replaced with revised version Wed, 29 Mar 2006 12:44:17 GMT (128kb) Title: UV light-induced atom desorption for large rubidium and potassium magneto-optical traps Authors: C. Klempt, T. van Zoest, T. Henninger, O. Topic, E. Rasel, W. Ertmer, and J. Arlt Comments: 8 pages, 9 figures Subj-class: Other Journal-ref: Phys. Rev. A 73, 013410 (2006) DOI: 10.1103/PhysRevA.73.013410 \\ ( http://arXiv.org/abs/cond-mat/0509241 , 128kb) ------------------------------------------------------------------------------ \\ Paper: quant-ph/0603265 Date: Wed, 29 Mar 2006 08:00:24 GMT (192kb) Title: Entanglement between remote continuous variable quantum systems: effects of transmission loss Authors: Lars Bojer Madsen, Klaus Molmer Comments: 7 pages, 4 figures \\ We study the effects of losses on the entanglement created between two separate atomic gases by optical probing and homodyne detection of the transmitted light. The system is well-described in the Gaussian state formulation. Analytical results quantifying the degree of entanglement between the two gases are derived and compared with the entanglement in a pair of light pulses generated by an EPR source. For low (high) transmission losses the highest degree of entanglement is obtained by probing with squeezed (antisqueezed) light. In an asymmetric setup where light is only sent one way through the atomic samples, we find that the logarithmic negativity of entanglement attains a constant value $-\log_2(N)$ with $N=1/3$ irrespectively of the loss along the transmission line. \\ ( http://arXiv.org/abs/quant-ph/0603265 , 192kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603821 Date: Thu, 30 Mar 2006 16:59:44 GMT (41kb) Title: Finite-temperature properties of quasi-2D Bose-Einstein condensates Authors: Kwangsik Nho and D. P. Landau Comments: 6 pages, 5 figures Subj-class: Statistical Mechanics Journal-ref: Phys. Rev. A 73, 033606 (2006) \\ Using the finite-temperature path integral Monte Carlo method, we investigate dilute, trapped Bose gases in a quasi-two dimensional geometry. The quantum particles have short-range, s-wave interactions described by a hard-sphere potential whose core radius equals its corresponding scattering length. The effect of both the temperature and the interparticle interaction on the equilibrium properties such as the total energy, the density profile, and the superfluid fraction is discussed. We compare our accurate results with both the semi-classical approximation and the exact results of an ideal Bose gas. Our results show that for repulsive interactions, (i) the minimum value of the aspect ratio, where the system starts to behave quasi-two dimensionally, increases as the two-body interaction strength increases, (ii) the superfluid fraction for a quasi-2D Bose gas is distinctly different from that for both a quasi-1D Bose gas and a true 3D system, i.e., the superfluid fraction for a quasi-2D Bose gas decreases faster than that for a quasi-1D system and a true 3D system with increasing temperature, and shows a stronger dependence on the interaction strength, (iii) the superfluid fraction for a quasi-2D Bose gas lies well below the values calculated from the semi-classical approximation, and (iv) the Kosterlitz-Thouless transition temperature decreases as the strength of the interaction increases. \\ ( http://arXiv.org/abs/cond-mat/0603821 , 41kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0507460 replaced with revised version Thu, 30 Mar 2006 15:57:12 GMT (323kb) Title: Stability of Bosonic atomic and molecular condensates near a Feshbach resonance Authors: Sourish Basu, Erich J. Mueller Comments: 4 pages, 2 figures Subj-class: Other \\ ( http://arXiv.org/abs/cond-mat/0507460 , 323kb) ------------------------------------------------------------------------------ \\ Paper: physics/0603255 Date: Thu, 30 Mar 2006 07:22:15 GMT (880kb) Title: Spin-Polarizing Cold Sodium Atoms in a Strong Magnetic Field Authors: K.M.R. van der Stam, A. Kuijk, R. Meppelink, J.M. Vogels, and P. van der Straten Comments: 7 pages, 9 figures, submitted to Phys. Rev. A Subj-class: Atomic Physics \\ The efficiency of evaporative cooling, which is used for the creation of a Bose Einstein condensate, depends strongly on the number of particles at the start of the evaporation. A high efficiency can be reached by filling the magneto-optical trap with a large number of atoms and subsequently transferring these atoms to the magnetic trap as efficiently as possible. In our case (for sodium) this efficiency is limited to 1/3, because the magnetic substates of the F = 1 state, which is used in the trapping process, are equally populated. This limit can be overcome by spin-polarizing the sample before the transfer. For sodium atoms, however, the improvement is very small when it is done in a small magnetic field due to the large number of optical transitions in combination with the high optical density. In this article we describe spin-polarizing sodium atoms in a high magnetic field. The transfer efficiency is increased by a factor of 2. The high magnetic field makes the process also more robust against variations in the magnetic field, the laser frequency and the polarization of the laser beam. \\ ( http://arXiv.org/abs/physics/0603255 , 880kb) ------------------------------------------------------------------------------Received on Mon Apr 03 2006 - 11:43:18 EST

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