Anomalous power law of quantum reversibility for classically regular dynamics

Jacquod, Ph.; Adagideli, I.; Beenakker, C. W. J.

Anomalous power law of quantum reversibility for classically regular dynamics

Authors

Jacquod, Ph.

Adagideli, I.

Beenakker, C. W. J.

Description

The Loschmidt Echo M(t) (defined as the squared overlap of wave packets evolving with two slightly different Hamiltonians) is a measure of quantum reversibility. We investigate its behavior for classically quasi-integrable systems. A dominant regime emerges where M(t) ~ t^{-alpha} with alpha=3d/2 depending solely on the dimension d of the system. This power law decay is faster than the result ~ t^{-d} for the decay of classical phase space densities.