Physical Review A
Quasiperiodicity versus mixing instability in a kicked quantum system
Theo Geisel
Abstract
A two-level system subject to quasiperiodically modulated kicking is investigated under the aspects of ergodic theory. For weak kicking strength \ensuremath{\kappa} the correlation functions exhibit quasiperiodic behavior, whose character changes with increasing \ensuremath{\kappa} as recurrences become infrequent. A quantum instability with a transition to mixing behavior that was suggested for similar models does not arise. Analytic results are obtained for the case where two of three characteristic frequencies are incommensurate.