title: Coherent backscattering of Bose-Einstein condensates in two-dimensional disorder potentials.
abstract: We study quantum transport of an interacting Bose-Einstein condensate in a two-dimensional disorder potential. In the limit of a vanishing atom-atom interaction, a sharp cone in the angle-resolved density of the scattered matter wave is observed, arising from constructive interference between amplitudes propagating along reversed scattering paths. Weak interaction transforms this coherent backscattering peak into a pronounced dip, indicating destructive instead of constructive interference. We reproduce this result, obtained from the numerical integration of the Gross-Pitaevskii equation, by a diagrammatic theory of weak localization in the presence of nonlinearity.
authors.affiliation: Institut für Theoretische Physik, Universität Regensburg, 93040 Regensburg, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Hartung
authors.forename: Thomas
authors.initials: T
authors.lastname: Wellens
authors.forename: Cord A
authors.initials: CA
authors.lastname: Müller
authors.forename: Klaus
authors.initials: K
authors.lastname: Richter
authors.forename: Peter
authors.initials: P
authors.lastname: Schlagheck