Phase-space localization and level spacing distributions for a driven rotor with mixed regular/chaotic dynamics Original Research Article

The classical-quantum correspondence for systems with mixed regular and chaotic dynamics can be conveniently analyzed by the quantum Husimi phase-space distribution. The entropy of this distribution can be used to classify the quantum states as “regular” or “chaotic”. The nearest-neighbor statistics is then investigated for different classes of states and compared with the semiclassical Berry-Robnik distribution to verify this classification and the assumption of uncorrelated spectra of different classes. Moreover, the phase-space entropy provides a global picture of quantum phase-space structures similar to the classical Poincaré section. Numerical results for a time periodic system with one degree of freedom monochromatically driven by an external force demonstrate the validity and usefulness of these semiclassical concepts.