Self-Trapping dynamics in a 2D optical lattice

POSTER

Abstract

We present a variational mean field model used to characterize our recent experiments on the expansion dynamics of an ultra cold gas of $^{87}$Rb atoms initially trapped in a two dimensional optical lattice. The expansion is driven by suddenly turning off the harmonic confinement potentials in all directions. \textit{In situ} measurements of the density profile vs time were performed for different lattice depths. The observed dynamics are characterized by an initial suppression of the transverse dynamics, followed by a ballistic expansion across the lattice after the initial interaction energy is converted into kinetic energy along the free expanding axial direction. The slow initial expansion is predicted to be a manifestation of macroscopic self-trapping. We present comparisons between our variational model and the measured profiles.

Authors

  • Shuming Li

    • JILA \& Department of Physics, University of Colorado, Boulder

  • Aaron Reinhard

    • Penn State University
    • The Pennsylvania State University
    • Physics Department, The Pennsylvania State University, University Park

  • Jean-Felix Riou

    • Penn State University
    • The Pennsylvania State University
    • Physics Department, The Pennsylvania State University, University Park

  • Laura Adams

    • Penn State University
    • The Pennsylvania State University
    • Physics Department, The Pennsylvania State University, University Park

  • Rafael Hipolito

    • Department of Physics, Boston University

  • Anatoli Polkovnikov

    • Department of Physics, Boston University

  • David Weiss

    • Penn State University
    • The Pennsylvania State University
    • Physics Department, The Pennsylvania State University, University Park

  • Ana Maria Rey

    • JILA, University of Colorado and National Institute of Standard and Technology, Boulder, CO 80309
    • JILA (CU and NIST), and Dep. of Physics, U Colorado, Boulder, CO 80309
    • JILA and University of Colorado
    • University of Colorado, NIST, and JILA
    • JILA/NIST, University of Colorado
    • JILA, NIST, University of Colorado
    • JILA \& Department of Physics, University of Colorado, Boulder