Decoherence and the quantum-classical limit in the presence of chaos

We investigate how decoherence affects the short-time separation between quantum and classical dynamics for classically chaotic systems, within the framework of a specific model. For a wide range of parameters, the distance between the corresponding phase-space distributions depends on a single parameter chi that relates an effective, Planck constant (h) over bar (eff), the Lyapunov coefficient, and, the, diffusion constant. This distance, peaks at a time that depends logarithmically on (h) over bar (eff), in agreement with previous estimations of the,separation time for Hamiltonian systems. However, for chi less than or similar to 1, the separation remains small, going down with (h) over bar (2)(eff), so the concept of separation time loses its meaning..