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-- ------------------------------------------------------------------------- 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/0603454 Date: Fri, 17 Mar 2006 09:53:39 GMT (463kb) Title: Self-localized impurities embedded in a one dimensional Bose-Einstein condensate and their quantum fluctuations Authors: Krzysztof Sacha and Eddy Timmermans Comments: 7 pages, 5 figures Subj-class: Other \\ We consider the self-localization of neutral impurity atoms in a Bose-Einstein condensate in a 1D model. Within the strong coupling approach, we show that the self-localized state exhibits parametric soliton behavior. The corresponding stationary states are analogous to the solitons of non-linear optics and to the solitonic solutions of the Schroedinger-Newton equation (which appears in models that consider the connection between quantum mechanics and gravitation). In addition, we present a Bogoliubov-de~Gennes formalism to describe the quantum fluctuations around the product state of the strong coupling description. Our fluctuation calculations yield the excitation spectrum and reveal considerable corrections to the strong coupling description. The knowledge of the spectrum allows a spectroscopic detection of the impurity self-localization phenomenon. \\ ( http://arXiv.org/abs/cond-mat/0603454 , 463kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603458 Date: Fri, 17 Mar 2006 19:28:02 GMT (100kb) Title: Dynamic response of one-dimensional interacting fermions Authors: M. Pustilnik, M. Khodas, A. Kamenev, L.I. Glazman Subj-class: Mesoscopic Systems and Quantum Hall Effect; Strongly Correlated Electrons \\ We evaluate the dynamic structure factor $S(q,\omega)$ of interacting one-dimensional spinless fermions with a nonlinear dispersion relation. The combined effect of the nonlinear dispersion and of the interactions leads to new universal features of $S(q,\omega)$. The sharp peak $S\propto q\delta(\omega-uq)$, characteristic for the Tomonaga-Luttinger model, broadens up; $S(q,\omega)$ for a fixed $q$ becomes finite at arbitrarily large $\omega$. The main spectral weight, however, is confined to a narrow frequency interval of the width $\delta\omega\sim q^2/m$. At the boundaries of this interval the structure factor exhibits power-law singularities with exponents depending on the interaction strength and on the wave number $q$. \\ ( http://arXiv.org/abs/cond-mat/0603458 , 100kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603461 Date: Fri, 17 Mar 2006 14:07:49 GMT (559kb) Title: Condensation of electron-hole pairs in a degenerate semiconductor at room temperature Authors: Peter P. Vasil'ev and Igor V. Smetenin Comments: 26 pages, 5 figures Submitted to Physical Review B Subj-class: Strongly Correlated Electrons \\ It has been theoretically shown that in large-density semiconductor plasma there exist an energy level of a bound electron-hole pair (a composite boson) at the band gap. Filling this level up occurs through the condensation of electron-hole pairs with the use of mediating photons of a resonant electromagnetic field. We have demonstrated that in the case of a strong degeneracy of the plasma the critical temperature of the condensation is determined by the Fermi energies of the plasma components rather than the order parameter D. The critical temperature can exceed 300 K at electron-hole densities as large as 6.1018 cm-3. The theoretical model is consistent with available experimental data \\ ( http://arXiv.org/abs/cond-mat/0603461 , 559kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603463 Date: Fri, 17 Mar 2006 15:08:23 GMT (388kb) Title: Low velocity quantum reflection of Bose-Einstein condensates Authors: T. A. Pasquini, M. Saba, G. Jo, Y. Shin, W. Ketterle, D. E. Pritchard, T. A. Savas, N. Mulders Comments: 4 figures Subj-class: Other \\ We studied quantum reflection of Bose-Einstein condensates at normal incidence on a square array of silicon pillars. For incident velocities of 2.5-26 mm/s observations agreed with theoretical predictions that the Casimir-Polder potential of a reduced density surface would reflect slow atoms with much higher probability. At low velocities (0.5-2.5 mm/s), we observed that the reflection probability saturated around 60% rather than increasing towards unity. We present a simple model which explains this reduced reflectivity as resulting from the combined effects of the Casimir-Polder plus mean field potential and predicts the observed saturation. Furthermore, at low incident velocities, the reflected condensates show collective excitations. \\ ( http://arXiv.org/abs/cond-mat/0603463 , 388kb) ------------------------------------------------------------------------------ \\ Paper: quant-ph/0603156 Date: Fri, 17 Mar 2006 17:10:59 GMT (16kb) Title: Exploring the Implementation of Quantum Random Walk using Bose-Enstein Condensate Authors: C.M. Chandrashekar Comments: 5 pages, 2 figures \\ We propose a scheme to implement the simplest and best studied version of quantum random walk, discrete Hadamard walk in one dimension using an ultra-cold neutral atom, Bose-Einstein condensate (BEC). Implementation of quantum walk using BEC gives access to the phenomena on a macroscopic scale. Addressing BEC using lasers to implement quantum random walk appears less complicated than addressing and analyzing quantum random walk using just cold neutral atoms. This paper uses stimulated Raman transition technique as unitary shift operator to impart momentum on coherent macroscopic sample of ultracold atoms, BEC, which are in schr\"odinger cat state in a far detuned optical dipole trap. The unitary shift operator followed by Hadamard rotation, rf pulse for BEC, implements one step of the Hadamard walk and to realize a sizable number of step, the process is iterated without restoring to intermediate measurement. With current dipole trap technology for BEC, it should be possible to implement enough steps to experimentally highlight the discrete quantum random walk using a macroscopic wave-packet and lead to further exploration of quantum random walks and its applications. \\ ( http://arXiv.org/abs/quant-ph/0603156 , 16kb) ------------------------------------------------------------------------------ \\ Paper: quant-ph/0603158 Date: Fri, 17 Mar 2006 20:32:34 GMT (41kb) Title: N Identical Particles Under Quantum Confinement: A Many-Body Dimensional Perturbation Theory Approach II, The Lowest-Order Wave Function I Authors: M. Dunn, D.K. Watson and J.G. Loeser Comments: 52 pages \\ In this paper we continue our development of a dimensional perturbation theory (DPT) treatment of N identical particles under quantum confinement. DPT is a beyond-mean-field method which is applicable to both weakly and strongly-interacting systems and can be used to connect both limits. In a previous paper we developed the formalism for low-order energies and excitation frequencies. This formalism has been applied to atoms, Bose-Einstein condensates and quantum dots. One major advantage of the method is that N appears as a parameter in the analytical expressions for the energy and so results for N up to a few thousand are easy to obtain. Other properties however, are also of interest, for example the density profile in the case of a BEC,and larger N results are desirable as well. The latter case requires us to go to higher orders in DPT. These calculations require as input zeroth-order wave functions and this paper, along with a subsequent paper, addresses this issue. \\ ( http://arXiv.org/abs/quant-ph/0603158 , 41kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603469 Date: Fri, 17 Mar 2006 22:49:54 GMT (166kb) Title: Dissociation dynamics of resonantly coupled bose-fermi mixtures in an optical lattice Authors: Takahiko Miyakawa and Pierre Meystre Comments: 9 pages, 10 figures Subj-class: Other \\ We consider the photodissociation of ground-state bosonic molecules trapped in an optical lattice potential into two-component fermionic atoms. The system is assumed to be described by a one-band resonantly-coupled Bose-Fermi Hubbard model. We show that in the strong fermion-fermion interaction limit the dissociation dynamics is governed by a spin-boson lattice Hamiltonian. In the framework of a mean-field analysis based on the Gutzwiller ansatz, we then examine the crossover of the dissociation from a regime of independent single-site dynamics to a regime of cooperative dynamics as the molecular tunneling increases. We also identify two types of self-trapping transitions, a {\it coherent} and an {\it incoherent} one, depending on the ratio of the repulsive molecule-molecule interaction strength to molecular tunneling. Finally, we show that in the limits of weak and strong intersite tunneling the mean-field solutions agree well with the results from the quantum optical Jaynes-Cummings and Tavis-Cummings models, respectively. \\ ( http://arXiv.org/abs/cond-mat/0603469 , 166kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603479 Date: Sun, 19 Mar 2006 00:29:25 GMT (8kb) Title: Study of the ground state energy density of a dilute Bose gas in the canonical transformation Authors: Hyun Sik Noh, Sang-Hoon Kim, Chul Koo Kim, and Mukunda P. Das Comments: 5 pages, 0 figure Subj-class: Statistical Mechanics \\ A ground state energy density of an interacting dilute Bose gas system is studied in the canonical transformation scheme. It is shown that the transformation scheme enables us to calculate a higher order correction of order $n a^3$ in the particle depletion and ground state energy density of a dilute Bose gas system, which corresponds to the density fluctuation contribution from the excited states. The coefficient of $n a^3$ term is shown to be $2(\pi - 8/3)$ for the particle depletion, and $16(\pi - 8/3)$ for the ground state energy density. \\ ( http://arXiv.org/abs/cond-mat/0603479 , 8kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603489 Date: Mon, 20 Mar 2006 04:02:37 GMT (219kb) Title: Comment on "Pairing and Phase Separation in a Polarized Fermi Gas" by G. B. Partridge, W. Li, R. I. Kamar, Y. Liao, R. G. Hulet, Science 311, 503 (2006) Authors: Martin W. Zwierlein and Wolfgang Ketterle Comments: 5 pages, 2 figures Subj-class: Superconductivity; Strongly Correlated Electrons \\ We show that Partridge et al. (Science 311, 503 (2006)) used inconclusive and incorrect criteria for superfluidity and phase separation. Simulations of their experiment suggest that anharmoncities of the trapping potential have caused the features which were interpreted as a signature of a quantum phase transition. \\ ( http://arXiv.org/abs/cond-mat/0603489 , 219kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603498 Date: Mon, 20 Mar 2006 08:55:37 GMT (682kb) Title: Pairing in a three component Fermi gas Authors: T. Paananen, J.-P. Martikainen, and P. Torma Comments: 10 pages, 3 figures Subj-class: Superconductivity \\ We consider pairing in a three-component gas of degenerate fermions. In particular, we solve the finite temperature mean-field theory of an interacting gas for a system where both interaction strengths and fermion masses can be unequal. At zero temperature we find a a possibility of a quantum phase transition between states associated with pairing between different pairs of fermions. On the other hand, finite temperature behavior of the three-component system reveals some qualitative differences from the two-component gas: for a range of parameters it is possible to have two different critical temperatures. The lower one corresponds to a transition between different pairing channels, while the higher one corresponds to the usual superfluid-normal transition. We discuss how these phase transitions could be observed in ultracold gases of fermionic atoms. \\ ( http://arXiv.org/abs/cond-mat/0603498 , 682kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603508 Date: Mon, 20 Mar 2006 11:10:42 GMT (36kb) Title: Comment on ``Sound velocity and multibranch Bogoliubov spectrum of an elongated Fermi superfluid in the BEC-BCS crossover" Authors: P. Capuzzi, P. Vignolo, F. Federici, and M. P. Tosi Comments: Comment on cond-mat/0510160 Subj-class: Other \\ The work by T. K. Ghosh and K. Machida [cond-mat/0510160 and Phys. Rev. A 73, 013613 (2006)] on the sound velocity in a cylindrically confined Fermi superfluid obeying a power-law equation of state is shown to make use of an improper projection of the sound wave equation. This inaccuracy fully accounts for the difference between their results and those previously reported by Capuzzi et al. [cond-mat/0509323 and Phys. Rev. A 73, 021603(R) (2006)]. In this Comment we show that both approaches lead exactly to the same result when the correct weight function is used in the projection. Plots of the correct behavior of the phonon and monopole-mode spectra in the BCS, unitary, and BEC limits are also shown. \\ ( http://arXiv.org/abs/cond-mat/0603508 , 36kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603513 Date: Mon, 20 Mar 2006 12:59:54 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 \\ We study theoretically a BEC loaded into an optical lattice in the tight-binding regime, with a second, incommensurate lattice acting as a perturbation. We find, using direct diagonalization of small systems and a large scale, number conserving mean field approach, the phase diagram of the model. We show that the superfluid, Mott-insulator and Bose-glass phases familiar from disordered systems appear here as well, with a localization transition occurring already in a 1D geometry, contrary to the well known Anderson localization. These results, together with calculations we have performed for realistic scenarios, suggest that this setup is well suited for available experimental realizations. \\ ( http://arXiv.org/abs/cond-mat/0603513 , 70kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603523 Date: Mon, 20 Mar 2006 17:37:16 GMT (168kb) Title: The dynamics of superfluid 4He Authors: Wouter Montfrooij, Eric Svensson, Rolf Verberg, Roelof Crevecoeur, Ignatz de Schepper Comments: 12 pages, 4 figures. Material closely related to W. Montfrooij and E.C. Svensson, Journal of Low Temperature Physics, Vol. 121, p. 293-302 (2000) Subj-class: Other \\ We present neutron scattering results for the dynamic response by superfluid and normal-fluid 4He and the results of a simple perturbation-theory analysis which allows us to describe all aspects of the observed behavior by considering only density fluctuations. We show that the three key features that are characteristic of the dynamic reponse of superfluid 4He, as well as their dramatic variations with temperature, can be attributed predominantly to the Bose statistics obeyed by all the 4He atoms. It appears that the presence of the Bose condensate exerts at most a minor influence on the dynamic response. \\ ( http://arXiv.org/abs/cond-mat/0603523 , 168kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0512565 replaced with revised version Sat, 18 Mar 2006 19:09:40 GMT (39kb) Title: Asymmetries in the tunneling probability of Bose-Einstein condensate in an accelerating optical lattice Authors: Valery S. Shchesnovich, Solange B. Cavalcanti Comments: 23 pages, 7 figures. Revised section V and changed figure 7. To appear in J. Phys. B: Atomic, Molecular and Optical Physics Subj-class: Other \\ ( http://arXiv.org/abs/cond-mat/0512565 , 39kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603404 replaced with revised version Sat, 18 Mar 2006 00:38:53 GMT (134kb) Title: Dynamical vanishing of the order parameter in a fermionic condensate Authors: Emil A. Yuzbashyan and Maxim Dzero Comments: 4 pages, 3 figures, minor polishing Subj-class: Superconductivity; Other \\ ( http://arXiv.org/abs/cond-mat/0603404 , 134kb) ------------------------------------------------------------------------------ \\ Paper: physics/0603157 Date: Mon, 20 Mar 2006 02:21:10 GMT (242kb) Title: Electrodynamic trapping of spinless neutral atoms with an atom chip Authors: T. Kishimoto, H. Hachisu, J. Fujiki, K. Nagato, M. Yasuda, and H. Katori Comments: 4pages, 4figures, to appear in Phys. Rev. Lett Subj-class: Atomic Physics \\ Three dimensional electrodynamic trapping of neutral atoms has been demonstrated. By applying time-varying inhomogeneous electric fields with micron-sized electrodes, nearly $10^2$ strontium atoms in the $^1S_0$ state have been trapped with a lifetime of 80 ms. In order to design the electrodes, we numerically analyzed the electric field and simulated atomic trajectories in the trap, which showed reasonable agreement with the experiment. \\ ( http://arXiv.org/abs/physics/0603157 , 242kb) ------------------------------------------------------------------------------ \\ Paper: physics/0603145 Date: Fri, 17 Mar 2006 21:14:10 GMT (268kb) Title: Slow Light Propagation in a Linear-Response Three-Level Atomic Vapor Authors: Wenhai Ji, Chunbai Wu and M. G. Raymer Comments: 15 pages, 8 figures Subj-class: Optics \\ We observe pulse delays of up to twenty times the input pulse duration when 200-ps laser pulses pass through a hot Rb 85 vapor cell. The pulse peak travels with a velocity equal to c/20, and the transmission is 5%. The measurements are in good agreement with a three-level linear-dispersion calculation. We are able to control the amount of delay by using a steady-state laser beam for optical pumping of the ground states prior to sending in the test pulse. \\ ( http://arXiv.org/abs/physics/0603145 , 268kb) ------------------------------------------------------------------------------ \\ Paper: physics/0509211 replaced with revised version Fri, 17 Mar 2006 01:23:56 GMT (1000kb) Title: Trap-induced resonances in controlled collisions of cesium atoms Authors: Rene Stock and Ivan H. Deutsch Comments: 9 pages, 8 figures, 1 table Subj-class: Atomic Physics; Other; Quantum Physics Journal-ref: Physical Review A 73, 032701 (2006) \\ ( http://arXiv.org/abs/physics/0509211 , 1000kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603561 Date: Tue, 21 Mar 2006 20:14:13 GMT (697kb) Title: Time evolution and matter wave interference in Fermi condensates Authors: Wei Zhang and C. A. R. Sa de Melo Comments: 4 pages, 4 figures Subj-class: Strongly Correlated Electrons \\ We discuss matter wave interference of Fermi condensates in strongly coupled s-wave and p-wave channels and the time evolution of a single cloud upon release from trap. In s-wave systems, where the order parameter is a complex scalar, we find that the interference patterns depend on the relative phase of the order parameters of the condensates. In p-wave systems involving the mixture of two-hyperfine states, we show that the interference pattern exhibits a polarization effect depending on the relative orientation of the two vector order parameters. However, in p-wave systems involving a single hyperfine state, we show that this angular effect reduces to an overall phase difference between the two interfering clouds, similar to s-wave. Lastly, we also point out that p-wave Fermi condensates exhibit an anisotropic expansion, reflecting the spatial anisotropy of the underlying interaction between fermions and the orbital nature of the vector order parameter. \\ ( http://arXiv.org/abs/cond-mat/0603561 , 697kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603190 replaced with revised version Tue, 21 Mar 2006 05:14:25 GMT (18kb) Title: Realization, Characterization, and Detection of Novel Superfluid Phases with Pairing between Unbalanced Fermion Species Authors: Kun Yang Comments: This is an invited contribution to a book titled "Pairing beyond BCS Theory in Fermionic Systems" (Mark Alford, John Clark and Armen Sedrakian, eds.), to be published by World Scientific. 21 pages. V4: added more references Subj-class: Superconductivity \\ ( http://arXiv.org/abs/cond-mat/0603190 , 18kb) ------------------------------------------------------------------------------ \\ Paper: quant-ph/0603185 Date: Tue, 21 Mar 2006 19:17:15 GMT (260kb) Title: Lasing and cooling in a hot cavity Authors: Thomas Salzburger Helmut Ritsch Comments: 11 pages, 6 figures \\ We present a microscopic laser model for many atoms coupled to a single cavity mode, including the light forces resulting from atom-field momentum exchange. Within a semiclassical description, we solve the equations for atomic motion and internal dynamics to obtain analytic expressions for the optical potential and friction force seen by each atom. When optical gain is maximum at frequencies where the light field extracts kinetic energy from the atomic motion, the dynamics combines optical lasing and motional cooling. From the corresponding momentum diffusion coefficient we predict sub-Doppler temperatures in the stationary state. This generalizes the theory of cavity enhanced laser cooling to active cavity systems. We identify the gain induced reduction of the effective resonator linewidth as key origin for the faster cooling and lower temperatures, which implys that a bad cavity with a gain medium can replace a high-Q cavity. In addition, this shows the importance of light forces for gas lasers in the low-temperature limit, where atoms can arrange in a periodic pattern maximizing gain and counteracting spatial hole burning. Ultimately, in the low temperature limit, such a setup should allow to combine optical lasing and atom lasing in single device. \\ ( http://arXiv.org/abs/quant-ph/0603185 , 260kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603590 Date: Wed, 22 Mar 2006 19:46:54 GMT (249kb) Title: Adiabatic loading of a Bose-Einstein condensate in a 3D optical lattice Authors: T. Gericke, F. Gerbier, A. Widera, S. Foelling, O. Mandel, and I. Bloch Subj-class: Other \\ We experimentally investigate the adiabatic loading of a Bose-Einstein condensate into an optical lattice potential. The generation of excitations during the ramp is detected by a corresponding decrease in the visibility of the interference pattern observed after free expansion of the cloud. We focus on the superfluid regime, where we show that the limiting time scale is related to the redistribution of atoms across the lattice by single-particle tunneling. \\ ( http://arXiv.org/abs/cond-mat/0603590 , 249kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0511684 replaced with revised version Wed, 22 Mar 2006 04:26:54 GMT (745kb) Title: Critical fluctuations in a soliton formation of attractive Bose-Einstein condensates Authors: Rina Kanamoto, Hiroki Saito, Masahito Ueda Comments: 14 pages, 13 figures Subj-class: Other Journal-ref: Phys. Rev. A 73, 033611 (2006) \\ ( http://arXiv.org/abs/cond-mat/0511684 , 745kb) ------------------------------------------------------------------------------ \\ Paper: physics/0512151 replaced with revised version Wed, 22 Mar 2006 17:58:00 GMT (448kb) Title: Double-impulse magnetic focusing of launched cold atoms Authors: Aidan S Arnold, Matthew J Pritchard, David A Smith and Ifan G Hughes Comments: 14 pages, 6 figures. Accepted for publication in New Journal of Physics Subj-class: Atomic Physics; Optics \\ ( http://arXiv.org/abs/physics/0512151 , 448kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603601 Date: Thu, 23 Mar 2006 00:11:51 GMT (32kb) Title: Two-band superfluidity from the BCS to the BEC limit Authors: M. Iskin and C. A. R. S{\'a} de Melo Comments: 4 pages and 3 figures Subj-class: Superconductivity; Other \\ We analyze the evolution of two-band superfluidity from the weak coupling Bardeen-Cooper-Schrieffer (BCS) to the strong coupling Bose-Einstein condensation (BEC) limit. When the interband interaction is tuned from negative to positive values, a quantum phase transition occurs from a 0-phase to a $\pi$-phase state, depending on the relative phase of two order parameters. Furthermore, population imbalances between the two bands can be created by tuning the intraband or interband interactions. We also find two undamped low energy collective excitations corresponding to in-phase and out-of-phase modes. Lastly, we derive the coupled Ginzburg-Landau equations, and show that they reduce to coupled Gross-Pitaevskii equations for two types of bosons in the BEC limit. \\ ( http://arXiv.org/abs/cond-mat/0603601 , 32kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603607 Date: Thu, 23 Mar 2006 05:57:26 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 \\ Scattering length, which can be measured in Bose-Einstein condensate and Feshbach molecule experiments, is extremely sensitive to the variation of fundamental constants, in particular, the electron-to-proton mass ratio (m_e/m_p or m_e/Lambda_{QCD}, where Lambda_{QCD} is the QCD scale). Based on single- and two-channel scattering model, we show how the variation of the mass ratio propagates to the scattering length. Our results suggest that variation of m_e/m_p on the level of 10^{-11}~10^{-14} can be detected near a narrow magnetic or an optical Feshbach resonance by monitoring the scattering length on the 1% level. Derived formulae may also be used to estimate the isotopic shift of the scattering length. \\ ( http://arXiv.org/abs/cond-mat/0603607 , 11kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0603631 Date: Thu, 23 Mar 2006 17:23:06 GMT (511kb) Title: Atom interferometer based on phase coherent splitting of Bose-Einstein condensates with an integrated magnetic grating Authors: A. G\"unther, S. Kraft, C. Zimmermann, and J. Fort\'agh Comments: 5 pages, 5 figures Subj-class: Other \\ We report the phase coherent splitting of Bose-Einstein condensates by means of a phase grating produced near the surface of a micro-electronic chip. A lattice potential with a period of $4\mu$m is generated by the superposition of static and oscillating magnetic fields. Precise control of the diffraction is achieved by controlling the currents in the integrated conductors. The interference of overlapping diffraction orders is observed after 8ms of propagation in a harmonic trap and subsequent ballistic expansion of the atomic ensemble. By analyzing the interference pattern we show a reproducible phase relation between the diffraction orders with an uncertainty given by the resolution of the diffraction grating. \\ ( http://arXiv.org/abs/cond-mat/0603631 , 511kb) ------------------------------------------------------------------------------ \\ Paper (*cross-listing*): gr-qc/0603089 Date: Wed, 22 Mar 2006 16:25:39 GMT (671kb) Title: Stability analysis of sonic horizons in Bose-Einstein condensates Authors: C. Barcelo, A. Cano, L.J. Garay and G. Jannes Comments: 14 pages, 7 figures (reduced resolution) Subj-class: General Relativity and Quantum Cosmology; Other \\ We examine the linear stability of various configurations in Bose-Einstein condensates with sonic horizons. These configurations are chosen in analogy with gravitational systems with a black hole horizon, a white hole horizon and a combination of both. We discuss the role of different boundary conditions in this stability analysis, paying special attention to their meaning in gravitational terms. We highlight that the stability of a given configuration, not only depends on its specific geometry, but especially on these boundary conditions. Under boundary conditions directly extrapolated from those in standard General Relativity, black hole configurations, white hole configurations and the combination of both into a black hole--white hole configuration are shown to be stable. However, we show that under other (less stringent) boundary conditions, configurations with a single black hole horizon remain stable, whereas white hole and black hole--white hole configurations develop instabilities associated to the presence of the sonic horizons. \\ ( http://arXiv.org/abs/gr-qc/0603089 , 671kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0508106 replaced with revised version Thu, 23 Mar 2006 11:38:56 GMT (245kb) Title: Splitting and merging an elongated Bose-Einstein condensate at finite temperature Authors: A. Mebrahtu, A. Sanpera and M. Lewenstein Comments: 8 pages, 6 figures Subj-class: Other Journal-ref: Phys. Rev. A 73, 033601 (2006) DOI: 10.1103/PhysRevA.73.033601 \\ ( http://arXiv.org/abs/cond-mat/0508106 , 245kb) ------------------------------------------------------------------------------ \\ Paper: cond-mat/0512556 replaced with revised version Thu, 23 Mar 2006 10:30:00 GMT (23kb) Title: Strongly interacting Fermi gases with density imbalance Authors: J. Kinnunen, L. M. Jensen, and P. Torma Comments: Added one reference. Published in PRL Subj-class: Strongly Correlated Electrons; Other; Superconductivity Journal-ref: Phys. Rev. Lett. 96, 110403 (2006) \\ ( http://arXiv.org/abs/cond-mat/0512556 , 23kb) ------------------------------------------------------------------------------ \\ Paper: quant-ph/0603214 Date: Thu, 23 Mar 2006 18:05:40 GMT (51kb) Title: Generation of a squeezed vacuum resonant on Rubidium D_1 line with periodically-poled KTiOPO_4 Authors: Takahito Tanimura, Daisuke Akamatsu, Yoshihiko Yokoi, Akira Furusawa, and Mikio Kozuma Comments: 4 pages, 4 figures \\ We report generation of a continuous-wave squeezed vacuum resonant on the Rb D_1 line (795 nm) using periodically poled KTiOPO_4 (PPKTP) crystals. With a frequency doubler and an optical parametric oscillator based on PPKTP crystals, we observed a squeezing level of -2.75 +- 0.14 dB and an anti-squeezing level of +7.00 +- 0.13 dB. This system could be utilized for demonstrating storage and retrieval of the squeezed vacuum, which is important for the ultra-precise measurement of atomic spins as well as quantum information processing. \\ ( http://arXiv.org/abs/quant-ph/0603214 , 51kb) ------------------------------------------------------------------------------ \\ Paper: quant-ph/0603216 Date: Thu, 23 Mar 2006 18:34:06 GMT (584kb) Title: Fourier-limited Raman velocimetry of laser-cooled, polarized, cesium atoms Authors: Julien Chab\'{e} (PhLAM, CERLA), Hans Lignier (PhLAM, CERLA), Pascal Szriftgiser (PhLAM, CERLA), Jean Claude Garreau (PhLAM, CERLA) Comments: 7 pages, 8 figures, revtex4, submitted to Phys. Rev. A Proxy: ccsd ccsd-00021689 \\ We describe and test experimentally a setup allowing efficient optical pumping of laser-cooled cesium atoms into the F=4, m=0 ground-state Zeeman sublevel, which is insensitive to magnetic perturbations. High resolution Raman stimulated spectroscopy is shown to produce Fourier-limited lines, allowing, in realistic experimental conditions, atomic velocity selection to one-fifth of a recoil velocity. \\ ( http://arXiv.org/abs/quant-ph/0603216 , 584kb) ------------------------------------------------------------------------------ \\ 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 \\ 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) ------------------------------------------------------------------------------Received on Mon Mar 27 2006 - 08:43:51 EST
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