Anisotropic 2D diffusive expansion of ultracold atoms in a disordered potential.
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.
Robert-de-Saint-Vincent
M
M
Laboratoire Charles Fabry de l'Institut d'Optique, Univ. Paris Sud, CNRS, campus polytechnique RD128, 91127 Palaiseau, France.
Brantut
J-P
JP
Allard
B
B
Plisson
T
T
Pezzé
L
L
Sanchez-Palencia
L
L
Aspect
A
A
Bourdel
T
T
Bouyer
P
P