title: Anisotropic 2D diffusive expansion of ultracold atoms in a disordered potential.
abstract: We study the horizontal expansion of vertically confined ultracold atoms in the presence of disorder. Vertical confinement allows us to realize a situation with a few coupled harmonic oscillator quantum states. The disordered potential is created by an optical speckle at an angle of 30° with respect to the horizontal plane, resulting in an effective anisotropy of the correlation lengths of a factor of 2 in that plane. We observe diffusion leading to non-gaussian density profiles. Diffusion coefficients, extracted from the experimental results, show anisotropy and strong energy dependence, in agreement with numerical calculations.
authors.affiliation: Laboratoire Charles Fabry de l'Institut d'Optique, Univ. Paris Sud, CNRS, campus polytechnique RD128, 91127 Palaiseau, France.
authors.forename: M
authors.initials: M
authors.lastname: Robert-de-Saint-Vincent
authors.forename: J-P
authors.initials: JP
authors.lastname: Brantut
authors.forename: B
authors.initials: B
authors.lastname: Allard
authors.forename: T
authors.initials: T
authors.lastname: Plisson
authors.forename: L
authors.initials: L
authors.lastname: Pezzé
authors.forename: L
authors.initials: L
authors.lastname: Sanchez-Palencia
authors.forename: A
authors.initials: A
authors.lastname: Aspect
authors.forename: T
authors.initials: T
authors.lastname: Bourdel
authors.forename: P
authors.initials: P
authors.lastname: Bouyer