Dynamical properties of a condensate in a moving random potential

Abstract

We study the dynamics of an inhomogeneous Bose-Einstein condensate subject to a one-dimensional harmonic trap and a moving random potential of finite extent. Above the critical velocity, a part of a condensate glues to the moving random potential with a consequent displacement of the condensate center-of-mass along the harmonic trap. We show that the center-of-mass turning point provides a direct measure of the average drag force acting on the condensate.

Probing quantum transport by engineering correlations in a speckle potential

“…[12,13] studied the transport of a homogeneous one-dimensional (1D) interacting Bose-Einstein condensate (BEC) in the presence of a moving random potential of finite extent L. They proved the presence of an Anderson localization regime by studying the transmission of the BEC through the potential and showing that it decays exponentially with L. However, in ordinary ultracold-atom experiments, BECs are trapped in a harmonic confinements and thus they are inhomogeneous. Transmission is no longer a well defined observable in such a geometry, however one can identify the presence of some localization effects by studying the time evolution of the BEC center-of-mass [14,15]. If the center-of-mass follows the moving random potential, the BEC is trapped by the random potential; it remains difficult to say if this localization is classical or induced by the interference of the scattered fluid.…”