Coherent back scattering and Anderson Localization of ultra cold atoms

An ensemble of ultra cold atoms released in a well-chosen disordered optical potential is a system that offers a privileged way to directly observe Anderson Localization. Localization has been observed in 1D [1,2] and 3D [3,4], while 2D experiments are promising [5]. Theory supports the conclusion that what we observe is AL [6,7], but a smoking gun of the role of coherence is still missing. Recently, we have observed CBS [8] (see Figure), an indisputable coherent effect in quantum transport, related to the first order manifestation of localization (weak localization).