Frequency response of the Loschmidt echo decay in an open driven nonlinear oscillator

Department of Mathematics and Physics, Electric Power University of North China - Baoding, PRC

Received: 15 August 2015
Accepted: 5 November 2015

Abstract

The decay of the Loschmidt echo and its relation to the frequency response of the underlying classical dynamics are investigated in an open Duffing system by means of the Wigner function. The initial Wigner function of the system is Gaussian and centered at a phase point (x₀, p₀). For different (x₀, p₀), significant peaks are observed in the frequency response curves of the Loschmidt echo decay during the evolution of the Wigner function. Furthermore, there is good correspondence between the frequency response curves of the Loschmidt echo decay and the underlying classical dynamics. This can be attributed to the increase of the fringes of the Wigner function by the external driving force, which can be revealed by the frequency response of the underlying classical dynamics.