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

Date: Mon, 10 Apr 2006 10:48:18 +1000 (EST)

Date: Mon, 10 Apr 2006 10:48:18 +1000 (EST)

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

Lots of papers again this week. Matt's arXiv home page is here:

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

Next week's email may be a day late due to Easter Monday being a holiday!

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/0603838 Date: Fri, 31 Mar 2006 06:21:15 GMT (789kb) Title: Modulation instability and solitary wave formation in two-component Bose-Einstein condensates Authors: Kenichi Kasamatsu, Makoto Tsubota Comments: 16 pages, 13 figures Subj-class: Other \\ We investigate nonlinear dynamics induced by the modulation instability of a two-component mixture in an atomic Bose-Einstein condensate. The nonlinear dynamics is examined using numerical simulations of the time-dependent coupled Gross-Pitaevskii equations. The unstable modulation grows from initially miscible condensates into various types of vector solitary waves, depending on the combinations of the sign of the coupling constants (intracomponent and intercomponent). We discuss the detailed features of the modulation instability, dynamics of solitary wave formation, and an analogy with the collapsing dynamics in a single-component condensate with attractive interactions. \\ ( http://arXiv.org/abs/cond-mat/0603838 , 789kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603857 Date: Fri, 31 Mar 2006 13:57:49 GMT (470kb) Title: Defect modes of a Bose-Einstein condensate in an optical lattice with a localized impurity Authors: V.A. Brazhnyi, V.V. Konotop, V.M. P\'erez-Garc\'{\i}a Comments: 14 pages, 9 Figures, 1 Table Subj-class: Soft Condensed Matter \\ We study defect modes of a Bose-Einstein condensate in an optical lattice with a localized defect within the framework of the one-dimensional Gross-Pitaevskii equation. It is shown that for a significant range of parameters the defect modes can be accurately described by an expansion over Wannier functions, whose envelope is governed by the coupled nonlinear Schr\"{o}dinger equation with a delta-impurity. The stability of the defect modes is verified by direct numerical simulations of the underlying Gross-Pitaevskii equation with a periodic plus defect potentials. We also discuss possibilities of driving defect modes through the lattice and suggest ideas for their experimental generation. \\ ( http://arXiv.org/abs/cond-mat/0603857 , 470kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603859 Date: Fri, 31 Mar 2006 18:09:07 GMT (66kb) Title: Ground state cooling of atoms in optical lattices Authors: M. Popp, J. J. Garcia-Ripoll, K. G. H. Vollbrecht, J. I. Cirac Comments: 12 pages, 7 figures Subj-class: Statistical Mechanics \\ We propose two schemes for cooling bosonic and fermionic atoms in an optical lattice potential to the ground state of the Mott-insulating regime. The first, algorithmic scheme is inspired by quantum computation. The second protocol is based on the sequential application of occupation number filtering. We provide a complete theoretical analysis of both schemes and predict the cooling efficiency in terms of the entropy. Our schemes do not require addressing of single lattice sites and use a novel method, which is based on coherent laser control, to perform very fast filtering operations. \\ ( http://arXiv.org/abs/cond-mat/0603859 , 66kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0501510 replaced with revised version Fri, 31 Mar 2006 18:42:42 GMT (31kb) Title: Factorization in Break-up and Recombination Processes for Atoms with a Large Scattering Length Authors: Eric Braaten and Dongqing Zhang Comments: 7 pages, 3 figures Subj-class: Other; Atomic and Molecular Clusters \\ ( http://arXiv.org/abs/cond-mat/0501510 , 31kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0507521 replaced with revised version Fri, 31 Mar 2006 16:07:52 GMT (100kb) Title: Dynamics of F=1 87Rb condensates at finite temperatures Authors: Jordi Mur-Petit, Montserrat Guilleumas, Artur Polls, Anna Sanpera, Maciej Lewenstein, Kai Bongs, Klaus Sengstock Comments: 6 pages + 5 figures; matches the published version (and corrects some typos there) Subj-class: Mesoscopic Systems and Quantum Hall Effect Journal-ref: Physical Review A 73, 013629 (2006) DOI: 10.1103/PhysRevA.73.013629 \\ ( http://arXiv.org/abs/cond-mat/0507521 , 100kb) ------------------------------------------------------------------------------ \\ Paper: quant-ph/0603280 Date: Thu, 30 Mar 2006 23:22:09 GMT (122kb) Title: Many-body quantum dynamics of polarisation squeezing in optical fibre Authors: J. F. Corney, P. D. Drummond, J. Heersink, V. Josse, G. Leuchs and U. L. Andersen Comments: 4 pages, 4 figures \\ We report new experiments that test quantum dynamical predictions of polarization squeezing for ultrashort photonic pulses in a birefringent fibre, including all relevant dissipative effects. This exponentially complex many-body problem is solved by means of a stochastic phase-space method. The squeezing is calculated and compared to experimental data, resulting in excellent quantitative agreement. From the simulations, we identify the physical limits to quantum noise reduction in optical fibres. The research represents a significant experimental test of first-principles time-domain quantum dynamics in a one-dimensional interacting Bose gas coupled to dissipative reservoirs. \\ ( http://arXiv.org/abs/quant-ph/0603280 , 122kb) ------------------------------------------------------------------------------ \\ Paper: physics/0603268 Date: Fri, 31 Mar 2006 15:42:14 GMT (537kb) Title: On the Role of Penning Ionization in Photoassociation Spectroscopy Authors: E. van der Zwan, D. van Oosten, D. Nehari, P. van der Straten, and H.T.C. Stoof Comments: 14 pages, 18 figures, submitted to the special issue on Cold Molecules of J. Phys. B Subj-class: Atomic Physics \\ We study the role of Penning ionization on the photoassociation spectra of He(^3S)-He(^3S). The experimental setup is discussed and experimental results for different intensities of the probe laser are shown. For modelling the experimental results we consider coupled-channel calculations of the crossing of the ground state with the excited state at the Condon point. The coupled-channel calculations are first applied to model systems, where we consider two coupled channels without ionization, two coupled channels with ionization, and three coupled channels, for which only one of the excited states is ionizing. Finally, coupled-channel calculations are applied to photoassociation of He(^3S)-He(^3S) and good agreement is obtained between the model and the experimental results. \\ ( http://arXiv.org/abs/physics/0603268 , 537kb) ------------------------------------------------------------------------------ \\ Paper: physics/0603263 Date: Thu, 30 Mar 2006 21:21:15 GMT (5kb) Title: Intelligent Design in the Physics Classroom? Authors: Travis Norsen Subj-class: Popular Physics; History of Physics \\ This fun polemical piece was written several months ago on a tip that the \emph{Chronicle of Higher Education} might be interested in publishing something like it. Sadly (both for me and, I think, for the \emph{Chronicle}'s readership) the editors didn't think it was of sufficient interest to the wider academic community. I am posting it here at the arxiv so that it can, nevertheless, be publicly available. If anyone out there wants to (suggest a place to) publish the piece, I'm all ears. \\ ( http://arXiv.org/abs/physics/0603263 , 5kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0604005 Date: Fri, 31 Mar 2006 22:39:33 GMT (35kb) Title: The relation between Feynman cycles and off-diagonal long-range order Authors: Daniel Ueltschi Comments: 4 pages Subj-class: Statistical Mechanics \\ The usual order parameter for the Bose-Einstein condensation involves the off-diagonal correlation function of Penrose and Onsager, but an alternative is Feynman's notion of infinite cycles. We present a formula that relates both order parameters. We discuss its validity with the help of rigorous results and heuristic arguments. The conclusion is that infinite cycles do not always represent the Bose condensate. \\ ( http://arXiv.org/abs/cond-mat/0604005 , 35kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0604006 Date: Fri, 31 Mar 2006 23:12:16 GMT (63kb) Title: Stability of fermionic Feshbach molecules in a Bose-Fermi mixture Authors: Alexander V. Avdeenkov, Daniele C. E. Bortolotti, John.L.Bohn Subj-class: Statistical Mechanics \\ In the wake of successful experiments in Fermi condensates, experimental attention is broadening to study resonant interactions in degenerate Bose-Fermi mixtures. Here we consider the properties and stability of the fermionic molecules that can be created in such a mixture near a Feshbach resonance (FR). To do this, we consider the two-body scattering matrix in the many-body environment, and assess its complex poles. The stability properties of these molecules strongly depend on their centre-of-mass motion, because they must satisfy Fermi statistics. At low centre-of-mass momenta the molecules are more stable than in the absence of the environment (due to Pauli-blocking effects), while at high centre-of-mass momenta nontrivial many body effects render them somewhat less stable. \\ ( http://arXiv.org/abs/cond-mat/0604006 , 63kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0604009 Date: Sat, 1 Apr 2006 07:00:04 GMT (394kb) Title: Bending-wave Instability of a Vortex Ring in a Trapped Bose-Einstein Condensate Authors: T.-L. Horng, S.-C. Gou, T.-C. Lin Comments: 4 pages, 4 figures Subj-class: Mesoscopic Systems and Quantum Hall Effect \\ Based on a velocity formula derived by matched asymptotic expansion, we investigate the dynamics of a circular vortex ring in an axisymmetric Bose-Einstein condensate in the Thomas-Fermi limit. The trajectory for an axisymmetrically placed and oriented vortex ring is entirely determined, revealing that the vortex ring generally precesses in condensate. The linear instability due to bending waves is investigated both numerically and analytically. General stability boundaries for various perturbed wavenumbers are computed. In particular, the excitation spectrum and the absolutely stable region for the static ring are analytically determined. \\ ( http://arXiv.org/abs/cond-mat/0604009 , 394kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0604035 Date: Mon, 3 Apr 2006 13:17:02 GMT (25kb) Title: Pair-correlation in Bose-Einstein Condensate and Fermi Superfluid of Atomic Gases Authors: Bimalendu Deb Comments: 11 pages, 3 figures, based on the lecture delivered at TC-2005, held at IACS, Kolkata Subj-class: Superconductivity \\ We describe pair-correlation inherent in the structure of many-particle ground state of quantum gases, namely, Bose Einstein condensate and Cooper-paired Fermi superfluid of atomic gases. We make a comparative study on the pair-correlation properties of these two systems. We discuss how to probe this pair-correlation by stimulated light scattering. This intrinsic pair-correlation may serve as a resource for many-particle entanglement. \\ ( http://arXiv.org/abs/cond-mat/0604035 , 25kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0604038 Date: Mon, 3 Apr 2006 11:46:49 GMT (909kb) Title: Precision measurement of spin-dependent interaction strengths for spin-1 and spin-2 87Rb atoms Authors: Artur Widera, Fabrice Gerbier, Simon Foelling, Tatjana Gericke, Olaf Mandel, Immanuel Bloch Comments: 11 pages, 5 figures Subj-class: Other \\ We report on precision measurements of spin-dependent interaction-strengths in the 87Rb spin-1 and spin-2 hyperfine ground states. Our method is based on the recent observation of coherence in the collisionally driven spin-dynamics of ultracold atom pairs trapped in optical lattices. Analysis of the Rabi-type oscillations between two spin states of an atom pair allows a direct determination of the coupling parameters in the interaction hamiltonian. We deduce differences in scattering lengths from our data that can directly be compared to theoretical predictions in order to test interatomic potentials. Our measurements agree with the predictions within 20%. The knowledge of these coupling parameters allows one to determine the nature of the magnetic ground state. Our data imply a ferromagnetic ground state for 87Rb in the f=1 manifold, in agreement with earlier experiments performed without the optical lattice. For 87Rb in the f=2 manifold the data points towards an antiferromagnetic ground state, however our error bars do not exclude a possible cyclic phase. \\ ( http://arXiv.org/abs/cond-mat/0604038 , 909kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0604063 Date: Mon, 3 Apr 2006 19:30:37 GMT (12kb) Title: Disorder-Induced Order: From Classical Spin Systems to Ultracold Atomic Gases Authors: Jan Wehr, Armand Niederberger, Laurent Sanchez-Palencia (LCFIO), Maciej Lewenstein (ITP-HANNOVER) Proxy: ccsd ccsd-00022177 Subj-class: Other \\ We propose a general mechanism of disorder-induced order by studying a particular case of classical ferromagnetic XY model in a random uniaxial field which breaks the continuous symmetry of the model. We prove rigorously that the system has spontaneous magnetization at temperature T=0, and we present strong evidence that this is also the case for small T>0. We discuss generalizations of this mechanism to various classical spin models and quantum systems. We propose a realization of this phenomenon with ultracold atoms in an optical lattice. \\ ( http://arXiv.org/abs/cond-mat/0604063 , 12kb) ------------------------------------------------------------------------------ \\ Paper: quant-ph/0603218 Date: Thu, 23 Mar 2006 19:05:47 GMT (214kb) Title: A Stern-Gerlach experiment for slow light Authors: Leon Karpa and Martin Weitz Comments: 11 pages, 3 figures. Nature Physics, in press Subj-class: Quantum Physics; Atomic Physics; Soft Condensed Matter \\ Electromagnetically induced transparency allows for light transmission through dense atomic media by means of quantum interference. Media exhibiting electromagnetically induced transparency have very interesting properties, such as extremely slow group velocities. Associated with the slow light propagation are quasiparticles, the so-called dark polaritons, which are mixtures of a photonic and an atomic contribution. We here demonstrate that these excitations behave as particles with a nonzero magnetic moment, which is in clear contrast to the properties of a free photon. It is found that light passing through a rubidium gas cell under the conditions of electromagnetically induced transparency is deflected by a small magnetic field gradient. The deflection angle is proportional to the optical propagation time through the cell. The observed beam deflection can be understood by assuming that dark state polaritons have an effective magnetic moment. Our experiment can be described in terms of a Stern-Gerlach experiment for the polaritons. \\ ( http://arXiv.org/abs/quant-ph/0603218 , 214kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0506210 replaced with revised version Mon, 3 Apr 2006 15:18:34 GMT (61kb) Title: Shock waves in a one-dimensional Bose gas: from a Bose-Einstein condensate to a Tonks gas Authors: Bogdan Damski Comments: 10 pages, small corrections with respect to the last submission, version accepted in Phys. Rev. A Report-no: LAUR-05-4188 Subj-class: Other; Pattern Formation and Solitons; Quantum Physics Journal-ref: Phys. Rev. A 73, 043601 (2006) \\ ( http://arXiv.org/abs/cond-mat/0506210 , 61kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0601392 replaced with revised version Mon, 3 Apr 2006 13:25:02 GMT (533kb) Title: Noise Thermometry with Two Weakly Coupled Bose-Einstein Condensates Authors: Rudolf Gati, Boerge Hemmerling, Jonas Foelling, Michael Albiez, Markus K. Oberthaler Comments: 4 pages, 4 figures Subj-class: Other \\ ( http://arXiv.org/abs/cond-mat/0601392 , 533kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0602616 replaced with revised version Mon, 3 Apr 2006 08:11:16 GMT (93kb) Title: Commensurate mixtures of ultra-cold atoms in one dimension Authors: L. Mathey Comments: 4 pages, 2 figures, v2: a few minor changes Subj-class: Other \\ ( http://arXiv.org/abs/cond-mat/0602616 , 93kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603340 replaced with revised version Mon, 3 Apr 2006 15:17:31 GMT (25kb) Title: Calogero-Sutherland gas of ultracold Bose atoms Authors: Yue Yu Comments: 4 pages,1 figure,update version Subj-class: Other; Statistical Mechanics \\ ( http://arXiv.org/abs/cond-mat/0603340 , 25kb) ------------------------------------------------------------------------------ \\ Paper: quant-ph/0604006 Date: Sun, 2 Apr 2006 13:19:58 GMT (322kb) Title: Regimes of stability of accelerator modes Authors: Rebecca Hihinashvili, Tali Oliker, Yaniv S. Avizrats, Alexander Iomin, Shmuel Fishman, Italo Guarneri Comments: Submitted to Physica D \\ The phase diagram of a simple area-preserving map, which was motivated by the quantum dynamics of cold atoms, is explored analytically and numerically. Periodic orbits of a given winding ratio are found to exist within wedge-shaped regions in the phase diagrams, which are analogous to the Arnol'd tongues which have been extensively studied for a variety of dynamical systems, mostly dissipative ones. A rich variety of bifurcations of various types are observed, as well as period doubling cascades. Stability of periodic orbits is analyzed in detail. \\ ( http://arXiv.org/abs/quant-ph/0604006 , 322kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0604086 Date: Tue, 4 Apr 2006 13:20:34 GMT (307kb) Title: Bright Matter-Wave Soliton Collisions in a Harmonic Trap: Regular and Chaotic Dynamics Authors: A. D. Martin, S. A. Gardiner and C. S. Adams Comments: 4 pages, 2 figures Subj-class: Other \\ Collisions between bright solitary waves in the 1D Gross-Pitaevskii equation with a harmonic potential, which models a trapped atomic Bose-Einstein condensate, are investigated theoretically. A particle analogy for the solitary waves is formulated, which is shown to be integrable for a two-particle system. The extension to three particles is shown to support chaotic regimes. Good agreement is found between the particle model and simulations of the full wave dynamics, suggesting that the dynamics can be described in terms of solitons both in regular and chaotic regimes, thus presenting a paradigm for chaos in wave-mechanics. \\ ( http://arXiv.org/abs/cond-mat/0604086 , 307kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0604095 Date: Tue, 4 Apr 2006 15:48:32 GMT (151kb) Title: Tuning the Mott transition in a Bose-Einstein condensate by multi-photon absorption Authors: C.E. Creffield and T.S. Monteiro Comments: 5 pages, 4 eps figures Subj-class: Other \\ We study the time-dependent dynamics of a Bose-Einstein condensate trapped in an optical lattice. Modeling the system as a Bose-Hubbard model, we show how applying a periodic driving field can induce coherent destruction of tunneling. In the low-frequency regime, we obtain the novel result that the destruction of tunneling displays extremely sharp peaks when the driving frequency is resonant with the depth of the trapping potential (``multi-photon resonances''), which allows the quantum phase transition between the Mott insulator and the superfluid state to be controlled with high precision. We further show how the waveform of the field can be chosen to maximize this effect. \\ ( http://arXiv.org/abs/cond-mat/0604095 , 151kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0509263 replaced with revised version Tue, 4 Apr 2006 12:41:06 GMT (659kb) Title: Vortex Tunneling and Transport Theory In Two-Dimensional Bose Condensates Authors: Assa Auerbach (Technion), Daniel P. Arovas (UCSD), and Sankalpa Ghosh (Okayama) Comments: A revised manuscript, including new predictions for observing vortex tunneling effects in cold atoms and superconducting films Subj-class: Superconductivity; Strongly Correlated Electrons \\ ( http://arXiv.org/abs/cond-mat/0509263 , 659kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0604115 Date: Wed, 5 Apr 2006 04:20:46 GMT (55kb) Title: Conditions of Low Dimensionality for Strongly Interacting Atoms Under a Transverse Trap Authors: J. P. Kestner, L.-M. Duan Comments: 9 pages, 7 figures Subj-class: Other \\ For a dilute atomic gas in a strong transverse trapping potential, one normally expects that, in the ground state, the gas will populate only the lowest transverse level. We show, however, that for the strongly interacting gas under a Feshbach resonance, the ground state includes a large fraction of atoms in excited levels of the trap, even if the gas is very dilute and the trap is very strong. This is because the effective atom-molecule coupling is typically enhanced to many times the trap mode spacing by an induced confinement along the untrapped dimension(s). Thus one cannot ''freeze out'' the transverse degrees of freedom except under certain conditions. \\ ( http://arXiv.org/abs/cond-mat/0604115 , 55kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0604139 Date: Wed, 5 Apr 2006 16:31:57 GMT (599kb) Title: Bose-Fermi Mixtures in a Three-dimensional Optical Lattice Authors: Kenneth G\"unter, Thilo St\"oferle, Henning Moritz, Michael K\"ohl, Tilman Esslinger Subj-class: Strongly Correlated Electrons \\ We have studied mixtures of fermionic $^{40}$K and bosonic $^{87}$Rb quantum gases in a three-dimensional optical lattice. We observe that an increasing admixture of the fermionic species diminishes the phase coherence of the bosonic atoms as measured by studying both the visibility of the matter wave interference pattern and the coherence length of the bosons. Moreover, we find that the attractive interactions between bosons and fermions lead to an increase of the boson density in the lattice which we measure by studying three-body recombination in the lattice. In our data we do not observe three-body loss of the fermionic atoms. An analysis of the thermodynamics of a noninteracting Bose-Fermi mixture in the lattice suggests a mechanism for sympathetic cooling of the fermions in the lattice. \\ ( http://arXiv.org/abs/cond-mat/0604139 , 599kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603699 replaced with revised version Wed, 5 Apr 2006 02:52:16 GMT (908kb) 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); Comments to ver.2: calculations without gravity were added, several typos corrected Subj-class: Other \\ ( http://arXiv.org/abs/cond-mat/0603699 , 908kb) ------------------------------------------------------------------------------ \\ Paper (*cross-listing*): math.DS/0405112 replaced with revised version Wed, 5 Apr 2006 18:45:15 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), submitted to Journal of Nonlinear Science, revised version includes additional discussion of physics and an additional conclusions/discussion section; some other revisions are sprinkled throughout the text 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) ------------------------------------------------------------------------------ \\ Paper: quant-ph/0604022 Date: Wed, 5 Apr 2006 13:26:39 GMT (224kb) Title: Vibration induced phase noise in Mach-Zehnder atom interferometers Authors: Alain Miffre (LCAR, PIIM), Marion Jacquey (LCAR), Matthias B\"{u}chner (LCAR), G\'{e}rard Tr\'{e}nec (LCAR), Jacques Vigu\'{e} (LCAR) Proxy: ccsd ccsd-00022231 \\ The high inertial sensitivity of atom interferometers has been used to build accelerometers and gyrometers but this sensitivity makes these interferometers very sensitive to the laboratory seismic noise. This seismic noise induces a phase noise which is large enough to reduce the fringe visibility in many cases. We develop here a model calculation of this phase noise in the case of Mach-Zehnder atom interferometers and we apply this model to our thermal lithium interferometer. We are thus able to explain the observed dependence of the fringe visibility with the diffraction order. The dynamical model developed in the present paper should be very useful to further reduce this phase noise in atom interferometers and this reduction should open the way to improved interferometers. \\ ( http://arXiv.org/abs/quant-ph/0604022 , 224kb) ------------------------------------------------------------------------------ \\ Paper: quant-ph/0604028 Date: Wed, 5 Apr 2006 18:59:26 GMT (103kb) Title: Phase noise due to vibrations in Mach-Zehnder atom interferometers Authors: A. Miffre (LCAR, Piim), M. Jacquey (LCAR), M. B\"{u}chner (LCAR), G. Tr\'{e}nec (LCAR), J. Vigu\'{e} (LCAR) Proxy: ccsd ccsd-00022285 \\ Atom interferometers are very sensitive to accelerations and rotations. This property, which has some very interesting applications, induces a deleterious phase noise due to the seismic noise of the laboratory and this phase noise is sufficiently large to reduce the fringe visibility in many experiments. We develop a model calculation of this phase noise in the case of Mach-Zehnder atom interferometers and we apply this model to our thermal lithium interferometer. We are able to explain the observed phase noise which has been detected through the rapid dependence of the fringe visibility with the diffraction order. We think that the dynamical model developed in the present paper should be very useful to reduce the vibration induced phase noise in atom interferometers, making many new experiments feasible. \\ ( http://arXiv.org/abs/quant-ph/0604028 , 103kb) ------------------------------------------------------------------------------ \\ Paper: physics/0604026 Date: Wed, 5 Apr 2006 02:24:36 GMT (244kb) Title: Sub-natural resonances due to ground state coherence in 6Li Authors: J. Fuchs, G. J. Duffy, W. J. Rowlands and A. M. Akulshin Comments: 13 pages, 10 figures Subj-class: Atomic Physics \\ We report sub-Doppler and sub-natural linewidth spectroscopy of 6Li on the D1 and D2 lines in both a vapour cell and an atomic beam. Electromagnetically induced transparency is created using co-propagating mutually coherent laser beams with a frequency difference equal to the hyperfine ground state splitting of 228.2 MHz. The effects of various optical polarization configurations and applied magnetic fields are investigated. In addition, we present an optical Ramsey spectroscopy technique which further reduces the observed resonance width. \\ ( http://arXiv.org/abs/physics/0604026 , 244kb) ------------------------------------------------------------------------------ \\ Paper (*cross-listing*): math.DS/0405112 replaced with revised version Wed, 5 Apr 2006 18:45:15 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), submitted to Journal of Nonlinear Science, revised version includes additional discussion of physics and an additional conclusions/discussion section; some other revisions are sprinkled throughout the text 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) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0604147 Date: Wed, 5 Apr 2006 21:22:48 GMT (221kb) Title: Skyrmion-like excitations in dynamical lattices Authors: P. G. Kevrekidis, R. Carretero-Gonzalez, D. J. Frantzeskakis, B. A. Malomed, and F. K. Diakonos Comments: 4 pages, 5 figures Subj-class: Other \\ We construct discrete analogs of Skyrmions in nonlinear dynamical lattices. The Skyrmion is built as a vortex soliton of a complex field, coupled to a dark radial soliton of a real field. Adjusting the Skyrmion ansatz to the lattice setting allows us to construct a ``baby-Skyrmion'' in two dimensions (2D) and extend it into the 3D case (1D counterparts of the Skyrmions are also found). Stability limits for these patterns are obtained analytically and verified numerically. The dynamics of unstable discrete Skyrmions is explored, and their stabilization by external potentials is discussed. \\ ( http://arXiv.org/abs/cond-mat/0604147 , 221kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0604149 Date: Wed, 5 Apr 2006 23:47:27 GMT (139kb) Title: BCS-BEC Crossover in Atomic Fermi Gases with a Narrow Resonance Authors: L. M. Jensen, H. M. Nilsen, and Gentaro Watanabe Comments: 12 pages, 14 figures Report-no: NORDITA-2006-10 Subj-class: Superconductivity; Strongly Correlated Electrons \\ We determine the effects on the BCS-BEC crossover of the energy dependence of the effective two-body interaction, which at low energies is determined by the effective range. To describe interactions with an effective range of either sign, we consider a single-channel model with a two-body interaction having an attractive square well and a repulsive square barrier. We investigate the two-body scattering properties of the model, and then solve the Eagles-Leggett equations for the zero temperature crossover, determining the momentum dependent gap and the chemical potential self-consistently. From this we investigate the dependence of the crossover on the effective range of the interaction. \\ ( http://arXiv.org/abs/cond-mat/0604149 , 139kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0604151 Date: Thu, 6 Apr 2006 01:58:01 GMT (155kb) Title: Instabilities leading to vortex lattice formation in rotating Bose-Einstein condensates Authors: N. G. Parker, R. M. W. van Bijnen, and A. M. Martin Comments: 5 pages, 2 figures Subj-class: Other \\ We present a comprehensive theoretical study of vortex lattice formation in atomic Bose-Einstein condensates confined by a rotating elliptical trap. We consider rotating solutions of the classical hydrodynamic equations, their response to perturbations, as well as time-dependent simulations. We discriminate three distinct, experimentally testable, regimes of instability: {\em ripple}, {\em interbranch}, and {\em catastrophic}. Under symmetry-breaking perturbations these instabilities lead to lattice formation even at zero temperature. While our results are consistent with previous theoretical and experimental results, they shed new light on lattice formation. \\ ( http://arXiv.org/abs/cond-mat/0604151 , 155kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0604154 Date: Thu, 6 Apr 2006 03:00:21 GMT (888kb) Title: Hanbury Brown-Twiss Interferometry for Fractional and Integer Mott Phases Authors: Ana Maria Rey, Indubala I. Satija and Charles W. Clark Comments: 13 pages, 15 figures Subj-class: Soft Condensed Matter; Other \\ Hanbury-Brown-Twiss interferometry (HBTI) is used to study integer and fractionally filled Mott Insulator (MI) phases in period-2 optical superlattices. In contrast to the quasimomentum distribution, this second order interferometry pattern exhibits high contrast fringes in the it insulating phases. Our detailed study of HBTI suggests that this interference pattern signals the various superfluid-insulator transitions and therefore can be used as a practical method to determine the phase diagram of the system. We find that in the presence of a confining potential the insulating phases become robust as they exist for a finite range of atom numbers. Furthermore, we show that in the trapped case the HBTI interferogram signals the formation of the MI domains and probes the shell structure of the system. \\ ( http://arXiv.org/abs/cond-mat/0604154 , 888kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0604162 Date: Thu, 6 Apr 2006 08:52:33 GMT (32kb) Title: Thermodynamical Properties of a Rotating Ideal Bose Gas Authors: Sebastian Kling, Axel Pelster Comments: Author Information under http://www.theo-phys.uni-essen.de/tp/ags/pelster_dir/ Subj-class: Statistical Mechanics \\ In a recent experiment, a Bose-Einstein condensate was trapped in an anharmonic potential which is well approximated by a harmonic and a quartic part. The condensate was set into such a fast rotation that the centrifugal force in the corotating frame overcompensates the harmonic part in the plane perpendicular to the rotation axis. Thus, the resulting trap potential became Mexican-hat shaped. We present an analysis for an ideal Bose gas which is confined in such an anharmonic rotating trap within a semiclassical approximation where we calculate the critical temperature, the condensate fraction, and the heat capacity. In particular, we examine in detail how these thermodynamical quantities depend on the rotation frequency. \\ ( http://arXiv.org/abs/cond-mat/0604162 , 32kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0604164 Date: Thu, 6 Apr 2006 08:57:59 GMT (37kb) Title: Fragmented condensates due to frustration of cold atoms in optical lattices Authors: J. J. Garcia-Ripoll, J. Pachos Subj-class: Strongly Correlated Electrons \\ A one dimensional optical lattice is considered where a second dimension is encoded in the internal states of the atoms giving effective ladder systems. Frustration is introduced by an additional optical lattice that induces tunnelling of superposed states. The effects of frustration range from the stabilization of the Mott insulator phase with ferromagnetic order, to the breakdown of superfluidity and the formation of fragmented condensates that resemble a Bose glass phase. \\ ( http://arXiv.org/abs/cond-mat/0604164 , 37kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0604170 Date: Thu, 6 Apr 2006 13:15:36 GMT (78kb) Title: Equilibration problem for the generalized Langevin equation Authors: Abhishek Dhar and Kshitij Wagh Comments: 4 pages, 1 figure Subj-class: Statistical Mechanics \\ We consider the problem of equilibration of a single oscillator system with dynamics given by the generalized Langevin equation. It is well-known that this dynamics can be obtained if one considers a model where the single oscillator is coupled to an infinite bath of harmonic oscillators which are initially in equilibrium. Using this equivalence we first determine the conditions necessary for equilibration for the case when the system potential is harmonic. We then give an example with a particular bath where we show that, even for parameter values where the harmonic case always equilibrates, with any finite amount of nonlinearity the system does not equilibrate for arbitrary initial conditions. We understand this as a consequence of the formation of nonlinear localized excitations similar to the discrete breather modes in nonlinear lattices. \\ ( http://arXiv.org/abs/cond-mat/0604170 , 78kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0604179 Date: Thu, 6 Apr 2006 17:55:00 GMT (323kb) Title: Localization of bosonic atoms by fermionic impurities in a 3d optical lattice Authors: S. Ospelkaus, C. Ospelkaus, O. Wille, M. Succo, P. Ernst, K. Sengstock and K. Bongs Comments: 4 pages, 4 figures Subj-class: Statistical Mechanics; Strongly Correlated Electrons \\ We observe a localized phase of ultracold bosonic quantum gases in a 3-dimensional optical lattice induced by a small contribution of fermionic atoms acting as impurities in a Fermi-Bose quantum gas mixture. In particular we study the dependence of this transition on the fermionic 40K impurity concentration by a comparison to the corresponding superfluid to Mott insulator transition in a pure bosonic 87Rb gas and find a significant shift in the transition parameter. The observed shift is larger than expected based on a mean-field argument, which is a strong indication that disorder-related effects play a significant role. \\ ( http://arXiv.org/abs/cond-mat/0604179 , 323kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0604183 Date: Thu, 6 Apr 2006 18:59:13 GMT (26kb) Title: Collisional relaxation of Feshbach molecules and three-body recombination in 87Rb Bose-Einstein condensates Authors: G. Smirne, R. M. Godun, D. Cassettari, V. Boyer, C. J. Foot, T. Volz, N. Syassen, S. Duerr, G. Rempe, M. D. Lee, K. Goral, T. Koehler Comments: 4 pages, 3 eps figures Subj-class: Other \\ We determine the magnetic field dependence of three-body recombination and atom-dimer collision rates in a 87Rb Bose-Einstein condensate (BEC) close to 1007 G. Our exact treatments of three-particle scattering explicitly include the dependence of the interactions on the Zeeman levels of each atom. The weakly coupled Feshbach resonance distorts the entire diatomic energy spectrum causing interferences in both loss phenomena. Our two independent experiments confirm the predicted resonance-enhanced recombination loss over a range of rate constants that spans four orders of magnitude. \\ ( http://arXiv.org/abs/cond-mat/0604183 , 26kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0604184 Date: Thu, 6 Apr 2006 19:11:37 GMT (43kb) Title: Two-species fermion mixtures with population imbalance Authors: M. Iskin and C. A. R. Sa de Melo Comments: 4 pages with 4 figures Subj-class: Superconductivity; Other \\ We analyze the phase diagram of uniform superfluidity for two-species fermion mixtures from the Bardeen-Cooper-Schrieffer (BCS) to Bose-Einstein condensation (BEC) limit as a function of the scattering parameter and population imbalance. We find at zero temperature that the phase diagram of population imbalance versus scattering parameter is asymmetric for non-equal masses, having a larger stability region for uniform superfluidity when the lighter fermions are in excess. In addition, we find topological quantum phase transitions associated with the disappearance or appearance of momentum space regions of zero quasiparticle energies. Lastly, near the critical temperature, we derive the Ginzburg-Landau equation, and show that it describes a dilute mixture of composite bosons and unpaired fermions in the BEC limit. \\ ( http://arXiv.org/abs/cond-mat/0604184 , 43kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603513 replaced with revised version Thu, 6 Apr 2006 09:16:52 GMT (67kb) 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 , 67kb) ------------------------------------------------------------------------------ \\ Paper: quant-ph/0604032 Date: Wed, 5 Apr 2006 20:22:08 GMT (59kb) Title: Excited state contribution to the Casimir-Polder force at finite temperature Authors: T.N.C.Mendes and C. Farina Comments: 3 pages, 3 figures \\ Using the master equation we calculate the contribution of the excited state of a two-level atom to its interacting potential with a perfectly conducting wall at finite temperature. For low temperature, $\hbar \omega_0/k_B T = k_0 \lambda_T\gg 1$, where $\omega_0 = k_0 c$ is the transition frequency of the atom and $\lambda_T$ is the thermal wavelength, we show that this contribution is very small $(\propto e^{-k_0\lambda_T})$. In the opposite limit $(k_0\lambda_T \ll 1)$, however, we show that the expression for the interacting potential, for all relevant distance regimes, becomes exactly the same as that for very short distances $(k_0 z \ll 1)$ and with the field in the vacuum state. \\ ( http://arXiv.org/abs/quant-ph/0604032 , 59kb) ------------------------------------------------------------------------------ \\ Paper: quant-ph/0604033 Date: Wed, 5 Apr 2006 20:54:11 GMT (125kb) Title: Casimir-Polder forces from density matrix formalism Authors: T.N.C. Mendes and C. Farina Comments: 11 pages, 3 figures \\ We use the density matrix formalism in order to calculate the energy level shifts, in second order on interaction, of an atom in the presence of a perfectly conducting wall in the dipole approximation. The thermal corrections are also examined when $\hbar \omega_0/k_B T = k_0 \lambda_T \gg 1$, where ${$\omega_0=k_0 c$}$ is the dominant transition frequency of the atom and $\lambda_T$ is the thermal length. When the distance $z$ between the atom and the wall is larger than $\lambda_T$ we find the well known result obtained from Lifshitz's formula, whose leading term is proportional to temperature and is independent of $c$, $\hbar$ and $k_0$. In the short distance limit, when $z\ll\lambda_T$, only very small corrections to the leading vacuum term occur. We also show, for all distance regimes, that the main thermal corrections are independent of $k_0$ (dispersion is not important) and dependent of $c$, which means that there is not a non-retarded regime for the thermal contributions. \\ ( http://arXiv.org/abs/quant-ph/0604033 , 125kb) ------------------------------------------------------------------------------ \\ Paper: quant-ph/0604034 Date: Wed, 5 Apr 2006 21:06:01 GMT (12kb) Title: A master equation approach for the interaction of an atom with a dielectric semi-infinite medium Authors: T.N.C. Mendes and C. Farina Comments: 9 pages \\ We use the master equation approach to calculate the energy level shifts of an atom in the presence of a general dielectric semi-infinite medium characterized by a dielectric constant $\epsilon(\omega)$. Particularly, we analyze the case of a non-dispersive medium for which we obtain a general expression for the interaction as well as the asymptotic behaviors for $k_0 z \ll 1$ (non-retarded regime) and $k_0 z \gg 1$ (retarded regime), where $\omega_0 = k_0 c$ is the main transition frequency of the atom. The limiting cases $\epsilon \simeq 1$ and $\epsilon \gg 1$ are discussed for both retarded and non-retarded limits. For the retarded limit, we compute the non-additivity contribution of van der Waals forces. \\ ( http://arXiv.org/abs/quant-ph/0604034 , 12kb) ------------------------------------------------------------------------------ \\ Paper: quant-ph/0604037 Date: Thu, 6 Apr 2006 18:20:33 GMT (136kb) Title: Optimal Storage of Photon States in Optically Dense Atomic Media Authors: Alexey V. Gorshkov, Axel Andre, Michael Fleischhauer, Anders S. Sorensen, Mikhail D. Lukin Comments: 4 pages, 3 figures \\ We derive an optimal control strategy for storage and retrieval of a photon wavepacket of any given shape in a Lambda-type atomic medium with a limited optical depth. The control is provided by an appropriately shaped classical laser field. We present a universal physical picture encompassing different pulse-storage techniques ranging from adiabatic reduction of the photon group velocity and pulse-propagation control via off-resonant Raman fields to photon-echo based approaches. When properly optimized, all three approaches yield identical maximum efficiencies, which only depend on the optical depth of the medium. Extending the model to include Doppler broadening, we find the surprising result that at high enough optical depth all atoms contribute coherently as if the medium were homogeneously broadened. \\ ( http://arXiv.org/abs/quant-ph/0604037 , 136kb) ------------------------------------------------------------------------------ \\ Paper: quant-ph/0604040 Date: Thu, 6 Apr 2006 09:36:48 GMT (85kb) Title: Gain narrowing in few-atom systems Authors: Tom Savels, Allard P. Mosk and Ad Lagendijk \\ Using a density matrix approach, we study the simplest systems that display both gain and feedback: clusters of 2 to 5 atoms, one of which is pumped. The other atoms supply feedback through multiple scattering of light. We show that, if the atoms are in each other's near-field, the system exhibits large gain narrowing and spectral mode redistribution. The observed phenomena are more pronounced if the feedback is enhanced. Our system is to our knowledge the simplest exactly solvable microscopic system which shows the approach to laser oscillation. \\ ( http://arXiv.org/abs/quant-ph/0604040 , 85kb) ------------------------------------------------------------------------------ \\ Paper: quant-ph/0604043 Date: Thu, 6 Apr 2006 13:14:10 GMT (554kb) Title: Coherent imaging of a pure phase object with classical incoherent light Authors: M. Bache, D. Magatti, A. Gatti, E. Brambilla, F. Ferri, and L.A. Lugiato Comments: 13 pages, 11 figures. To appear in Physical Review A \\ By using the ghost imaging technique, we experimentally demonstrate the reconstruction of the diffraction pattern of a {\em pure phase} object by using the classical correlation of incoherent thermal light split on a beam splitter. The results once again underline that entanglement is not a necessary feature of ghost imaging. The light we use is spatially highly incoherent with respect to the object ($\approx 2 \mu$m speckle size) and is produced by a pseudo-thermal source relying on the principle of near-field scattering. We show that in these conditions no information on the phase object can be retrieved by only measuring the light that passed through it, neither in a direct measurement nor in a Hanbury Brown-Twiss (HBT) scheme. In general, we show a remarkable complementarity between ghost imaging and the HBT scheme when dealing with a phase object. \\ ( http://arXiv.org/abs/quant-ph/0604043 , 554kb) ------------------------------------------------------------------------------Received on Mon Apr 10 2006 - 10:48:18 EST

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