13,554 research outputs found

    Angular Momentum Conservation Law for Randall-Sundrum Models

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    In Randall-Sundrum models, by the use of general Noether theorem, the covariant angular momentum conservation law is obtained with the respect to the local Lorentz transformations. The angular momentum current has also superpotential and is therefore identically conserved. The space-like components JijJ_{ij} of the angular momentum for Randall-Sundrum models are zero. But the component J04J_{04} is infinite.Comment: 10 pages, no figures, accepted by Mod. Phys. Lett.

    Efficient fluorescence collection from trapped ions with an integrated spherical mirror

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    Efficient collection of fluorescence from trapped ions is crucial for quantum optics and quantum computing applications, specifically, for qubit state detection and in generating single photons for ion-photon and remote ion entanglement. In a typical setup, only a few per cent of ion fluorescence is intercepted by the aperture of the imaging optics. We employ a simple metallic spherical mirror integrated with a linear Paul ion trap to achieve photon collection efficiency of at least 10% from a single Ba+^+ ion. An aspheric corrector is used to reduce the aberrations caused by the mirror and achieve high image quality.Comment: 5 pages and 4 figure

    Quantum three-body system in D dimensions

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    The independent eigenstates of the total orbital angular momentum operators for a three-body system in an arbitrary D-dimensional space are presented by the method of group theory. The Schr\"{o}dinger equation is reduced to the generalized radial equations satisfied by the generalized radial functions with a given total orbital angular momentum denoted by a Young diagram [μ,ν,0,...,0][\mu,\nu,0,...,0] for the SO(D) group. Only three internal variables are involved in the functions and equations. The number of both the functions and the equations for the given angular momentum is finite and equal to (μν+1)(\mu-\nu+1).Comment: 16 pages, no figure, RevTex, Accepted by J. Math. Phy

    Dynamical mean-field equations for strongly interacting fermionic atoms in a potential trap

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    We derive a set of dynamical mean-field equations for strongly interacting fermionic atoms in a potential trap across a Feshbach resonance. Our derivation is based on a variational ansatz, which generalizes the crossover wavefunction to the inhomogeneous case, and the assumption that the order parameter is slowly varying over the size of the Cooper pairs. The equations reduce to a generalized time-dependent Gross-Pitaevskii equation on the BEC side of the resonance. We discuss an iterative method to solve these mean-field equations, and present the solution for a harmonic trap as an illustrating example to self-consistently verify the approximations made in our derivation.Comment: replaced with the published versio

    Independent Eigenstates of Angular Momentum in a Quantum N-body System

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    The global rotational degrees of freedom in the Schr\"{o}dinger equation for an NN-body system are completely separated from the internal ones. After removing the motion of center of mass, we find a complete set of (2+1)(2\ell+1) independent base functions with the angular momentum \ell. These are homogeneous polynomials in the components of the coordinate vectors and the solutions of the Laplace equation, where the Euler angles do not appear explicitly. Any function with given angular momentum and given parity in the system can be expanded with respect to the base functions, where the coefficients are the functions of the internal variables. With the right choice of the base functions and the internal variables, we explicitly establish the equations for those functions. Only (3N-6) internal variables are involved both in the functions and in the equations. The permutation symmetry of the wave functions for identical particles is discussed.Comment: 24 pages, no figure, one Table, RevTex, Will be published in Phys. Rev. A 64, 0421xx (Oct. 2001

    Entanglement of two atomic samples by quantum non-demolition measurements

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    This paper presents simulations of the state vector dynamics for a pair of atomic samples which are being probed by phase shift measurements on an optical beam passing through both samples. We show how measurements, which are sensitive to different atomic components, serve to prepare states which are close to being maximally entangled.Comment: 8 pages, 8 figures, REVTeX

    Broadband laser cooling of trapped atoms with ultrafast pulses

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    We demonstrate broadband laser cooling of atomic ions in an rf trap using ultrafast pulses from a modelocked laser. The temperature of a single ion is measured by observing the size of a time-averaged image of the ion in the known harmonic trap potential. While the lowest observed temperature was only about 1 K, this method efficiently cools very hot atoms and can sufficiently localize trapped atoms to produce near diffraction-limited atomic images
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