31 research outputs found
Quantum Versus Classical Decay Laws in Open Chaotic Systems
We study analytically the time evolution in decaying chaotic systems and
discuss in detail the hierarchy of characteristic time scales that appeared in
the quasiclassical region. There exist two quantum time scales: the Heisenberg
time t_H and the time t_q=t_H/\sqrt{\kappa T} (with \kappa >> 1 and T being the
degree of resonance overlapping and the transmission coefficient respectively)
associated with the decay. If t_q < t_H the quantum deviation from the
classical decay law starts at the time t_q and are due to the openness of the
system. Under the opposite condition quantum effects in intrinsic evolution
begin to influence the decay at the time t_H. In this case we establish the
connection between quantities which describe the time evolution in an open
system and their closed counterparts.Comment: 3 pages, REVTeX, no figures, replaced with the published version
(misprints corrected, references updated
Quantum dephasing and decay of classical correlation functions in chaotic systems
We discuss the dephasing induced by the internal classical chaotic motion in
the absence of any external environment. To this end we consider a suitable
extension of fidelity for mixed states which is measurable in a Ramsey
interferometry experiment. We then relate the dephasing to the decay of this
quantity which, in the semiclassical limit, is expressed in terms of an
appropriate classical correlation function. Our results are derived
analytically for the example of a nonlinear driven oscillator and then
numerically confirmed for the kicked rotor model.Comment: 14 pages, 1 figur