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DY: Fachverband Dynamik und Statistische Physik

DY 10: Internal Symposium: Controlling Dirty Bosons: Disorder Effects on BECs

DY 10.2: Vortrag

Dienstag, 26. Februar 2008, 10:00–10:25, MA 001

Coherent backscattering of Bose-Einstein condensates from 2D disorder potentials — •Peter Schlagheck — Institut für Theoretische Physik, Universität Regensburg, 93040 Regensburg, Germany

We investigate the quasi-stationary transport of Bose-Einstein condensates through two-dimensional disorder potentials of finite thickness. Our numerical approach is based on the integration of the Gross-Pitaevskii equation in presence of a source term that simulates the continuous injection of matter waves onto the disorder potential. For noninteracting atoms, the constructive interference between reflected semiclassical paths and their time-reversed counterparts leads to a weak localization phenomenon, namely the enhanced backreflection of atoms into the direction that is opposite to the incident beam. We show that this peak of coherent backscattering is inverted and transformed into a dip by the presence of a weak interaction between the atoms. This anti-localization phenomenon is reproduced by analytical calculations of the transport process and can be related to similar nonlinear effects in the scattering of light through disordered atomic media.