Decoherence and Loschmidt echoes: Quantum against Classical

Abstract

Some recent theoretical results on the stability of quantum dynamics against perturbations of the Hamiltonian the so-called Loschmidt echoes and their relation to various decoherence measures are reviewed. We show that the representation of Loschmidt echoes in terms of the Wigner function can explain some seemingly paradoxical behavior of the quantum-classical correspondence.