Transport and localization of Bose-Einstein condensates in presence of disorder
Dr. Peter Schlagheck
Universität Regensburg, Germany
Thursday, 29 May 2008, 13:30
Seminar room F
Abstract:
In my talk, I will present our research activities on transport processes of
interacting Bose-Einstein condensates in presence of dimensionally restricted
disorder potentials. We study these processes by numerically integrating the
Gross-Pitaevskii equation in presence of an external source that simulates the
quasi-stationary injection of coherent matter waves onto the disorder region.
For the case of one-dimensional disorder potentials, we find that the presence
of the atom-atom interaction leads to a cross-over from an exponential to an
algebraic decrease of the average transmission with the disorder length,
which represents a significant deviation from the scenario of Anderson
localization. For two-dimensional disorder potentials, the presence of
interaction reverts the phenomenon of weak localization and leads to a
cone-shaped dip, instead of a peak, in the angle-resolved current of
backscattered atoms. Our numerical findings are corroborated by analytical
approaches based, in the 1D case, on transfer-matrix-type methods and, in the
2D case, on nonlinear diagrammatic perturbation theory.