Nonlinear transport of Bose-Einstein condensates through waveguides with disorder.

Peter Schlagheck

Universität Regensburg

The coherent flow of a Bose-Einstein condensate in a disordered magnetic waveguide is investigated. We present analytical and numerical studies of realistic transport processes in quasi one-dimensional disorder potentials that are created on atom chips. We find that a repulsive interaction between the condensate atoms induces different transport regimes. For weak interactions we observe a stationary flow which shows typical signatures of localization; in this regime the transmission decreases exponentially with the length of the disorder region. We identify a critical value for the interaction beyond which the system exhibits a transition towards a time-depedent flow with an algebraic decay of the time-averaged transmission. A comparison to a full three-dimensional simulation of the transport process through the disordered waveguide is finally presented.