789,857 research outputs found

    Van der Waals interaction between an atom with spherical plasma shell

    Get PDF
    We consider the van der Waals energy of an atom near the infinitely thin sphere with finite conductivity which model the fullerene. We put the sphere into spherical cavity inside the infinite dielectric media, then calculate the energy of vacuum fluctuations in framework of the zeta-function approach. The energy for a single atom is obtained from this expression by consideration of the rare media. In the limit of the infinite radius of the sphere the Casimir-Polder expression for an atom and plate is recovered. For finite radius of sphere the energy of an atom monotonously falls down as d3d^{-3} close to the sphere and d7d^{-7} far from the sphere. For hydrogen atom on the surface of the fullerene C60C_{60} we obtain that the energy is 3.8eV3.8 eV. We obtain also that the polarizability of fullerene is merely cube of its radius.Comment: 10 pages, 5 figure

    Reversible quantum teleportation in an optical lattice

    Get PDF
    We propose a protocol, based on entanglement procedures recently suggested by [D. Jaksch et al., Phys. Rev. Lett. 82, 1975 (1999)], which allows the teleportation of an unknown state of a neutral atom in an optical lattice to another atom in another site of the lattice, without any irreversible detection.Comment: 8 pages, 3 figure

    Hydration of a B-DNA Fragment in the Method of Atom-atom Correlation Functions with the Reference Interaction Site Model Approximation

    Full text link
    We propose an efficient numerical algorithm for solving integral equations of the theory of liquids in the Reference Interaction Site Model (RISM) approximation for infinitely dilute solution of macromolecules with a large number of atoms. The algorithm is based on applying the nonstationary iterative methods for solving systems of linear algebraic equations. We calculate the solvent-solute atom-atom correlation functions for a fragment of the B-DNA duplex d(GGGGG).d(CCCCC) in infinitely dilute aqueous solution. The obtained results are compared with available experimental data and results from computer simulations.Comment: 9 pages, RevTeX, 9 pages of ps figures, accepted for publications in JC

    Superradiance for atoms trapped along a photonic crystal waveguide

    Get PDF
    We report observations of superradiance for atoms trapped in the near field of a photonic crystal waveguide (PCW). By fabricating the PCW with a band edge near the D1_1 transition of atomic cesium, strong interaction is achieved between trapped atoms and guided-mode photons. Following short-pulse excitation, we record the decay of guided-mode emission and find a superradiant emission rate scaling as ΓˉSRNˉΓ1D\bar{\Gamma}_{\rm SR}\propto\bar{N}\cdot\Gamma_{\rm 1D} for average atom number 0.19Nˉ2.60.19 \lesssim \bar{N} \lesssim 2.6 atoms, where Γ1D/Γ0=1.1±0.1\Gamma_{\rm 1D}/\Gamma_0 =1.1\pm0.1 is the peak single-atom radiative decay rate into the PCW guided mode and Γ0\Gamma_{0} is the Einstein-AA coefficient for free space. These advances provide new tools for investigations of photon-mediated atom-atom interactions in the many-body regime.Comment: 11 pages, 10 figure

    The controlled teleportation of an arbitrary two-atom entangled state in driven cavity QED

    Full text link
    In this paper, we propose a scheme for the controlled teleportation of an arbitrary two-atom entangled state ϕ>12=agg>12+bge>12+ceg>12+dee>12|\phi>_{12}=a|gg>_{12}+b|ge>_{12}+c|eg>_{12}+d|ee>_{12} in driven cavity QED. An arbitrary two-atom entangled state can be teleported perfectly with the help of the cooperation of the third side by constructing a three-atom GHZ entangled state as the controlled channel. This scheme does not involve apparent (or direct) Bell-state measurement and is insensitive to the cavity decay and the thermal field. The probability of the success in our scheme is 1.0.Comment: 10 page
    corecore