Laboratoire de Physique Théorique
Toulouse - UMR 5152

The atomic kicked rotor is a paradigm for studying quantum chaos and Anderson localization phenomena in atomic systems. Carefully engineering the kicked rotor Hamiltonian [1] allowed us to experimentally investigate the coherent nature of the interference paths which represent the building blocks of the localization. In particular, we observed the "enhanced return to the origin" phenomenon, a manifestation of weak localisation closely related to the "coherent back scattering".

Moreover, more subtle interference mechanisms lead to the so-called "Coherent Forward Scattering" (CFS) which has been theoretically predicted recently [2], and represent a genuine signature of the Anderson (strong) localisation. We will present the first experimental evidence of the observation of CFS and discuss two key distinctive features : the characteristic timescale and robustness with respect to time-reversal-symmetry breaking.

[1] C. Tian, A. Kamenev, and A. Larkin, Phys. Rev. B 72, 045108 (2005).

[2] T. Karpiuk, N. Cherroret, K. Lee, B. Grémaud, C. A. Mueller, and C. Miniatura, Phys. Rev. Lett. 109, 190601 (2012).