Quantum diffusion in the quasiperiodic kicked rotorH. Lignier1, J. C. Garreau1, P. Szriftgiser1 and D. Delande2
1 Laboratoire de Physique des Lasers, Atomes et Molécules, UMR CNRS 8523 Université des Sciences et Technologies de Lille F-59655, Villeneuve d'Ascq Cedex, France
2 Laboratoire Kastler Brossel, Tour 12, Etage 1 4 Place Jussieu, F-75005 Paris, France
received 1 July 2004; accepted in final form 19 November 2004
published online 24 December 2004
We study the mechanisms responsible for quantum diffusion in the quasiperiodic kicked rotor. We report experimental measurements of the diffusion constant on the atomic version of the system and develop a theoretical approach (based on the Floquet theorem) explaining the observations, especially the "sub-Fourier" character of the resonances observed in the vicinity of exact periodicity, i.e. the ability of the system to distinguish two neighboring driving frequencies in a time shorter than the inverse of the difference of the two frequencies.
05.45.Mt - Quantum chaos; semiclassical methods.
32.80.Lg - Mechanical effects of light on atoms, molecules, and ions.
32.80.Pj - Optical cooling of atoms; trapping.
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