Quantitative study of amplitude noise effects on dynamical localization

We study the motion of cold atoms in a pulsed standing wave of light, which constitutes an experimental realization of the quantum kicked rotor. This system exhibits dynamical localization, where quantum effects suppress clas sical momentum diffusion. As we introduce amplitude noise, the coherences t hat lead to localization are destroyed, resulting in restored diffusion. Fo r high levels of noise, we find that the experiment is well described by a classical model, suggesting that classical behavior has been restored. We p resent a detailed experimental study of this noise-induced transition from quantum to classical behavior.