We use ultra cold atoms in a disordered potential created with a laser speckle, to study Anderson Localization (AL) and Coherent Back Scattering (CBS). Localization has been observed in 1D and 3D, and 2D experiments are promising. Theory supports the conclusion that what we observe is AL, but a direct evidence of the role of coherence is desirable. Recently, we have observed CBS, an indisputable coherent effect in quantum transport, related to the first order manifestation of localization (weak localization).

Institut d’Optique, Palaiseau