DECOHERENCE, CHAOS, AND THE 2ND LAW

Quantum wave function of a chaotic system spreads rapidly over distanc es on which the potential is significantly nonlinear. As a result, the effective force is no longer just a gradient of the potential, and pr edictions of classical and quantum dynamics begin to differ. We show h ow the interaction with the environment limits distances over which qu antum coherence can persist, and therefore reconciles quantum dynamics with classical Hamiltonian chaos. The entropy production rate for suc h open chaotic systems exhibits a sharp transition between reversible and dissipative regimes, where it is set by the chaotic dynamics.