It is well established that classical chaotic motion is suppressed by quantum mechanics. The paradigm theoretical system has been the ¿-kicked rotor, where the suppression manifests itself as dynamical localization. This effect is saturation of momentum growth after the quantum break time, with a resulting exponentially localized distribution. Classical analyses of this system have also identified regimes of anomalous diffusion, characterized by “Lévy-type” flights in phase space . This behavior is considerably more complex than simple diffusion and has attracted much interest in recent years. The quantum system was predicted to exhibit an increase in localization length near regions of anomalous diffusion , and recent theoretical work predicts very large growth of energy in this case, even for systems that are far from the semiclassical limit .
© 1998 Optical Society of AmericaPDF Article