Phys. Rev. E 64, 055203(R) (2001) [4 pages]Golden rule decay versus Lyapunov decay of the quantum Loschmidt echo
The overlap of two wave packets evolving in time with slightly different Hamiltonians decays exponentially ∝e-γt, for perturbation strengths U greater than the level spacing Δ. We present numerical evidence for a dynamical system that the decay rate γ is given by the smallest of the Lyapunov exponent λ of the classical chaotic dynamics and the level broadening U2/Δ that follows from the golden rule of quantum mechanics. This implies the range of validity U>√λΔ for the perturbation-strength independent decay rate discovered by Jalabert and Pastawski [Phys. Rev. Lett. 86, 2490 (2001)]. © 2001 The American Physical Society URL:
http://link.aps.org/doi/10.1103/PhysRevE.64.055203
DOI:
10.1103/PhysRevE.64.055203
PACS:
05.45.Mt, 05.45.Pq, 42.50.Md, 76.60.Lz
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