Loschmidt echo and Berry phase around degeneracies in nonlinear systems
Quantum Physics
2009-11-13 v1
Abstract
We study the Loschmidt echo and Berry phase in a nonlinear system transported around a double and triple degeneracy. The nonlinearity of the system makes the Berry phase different from that in linear systems. We propose a witness of nonlinearity for the nonlinear system and show its dependence on the parameters of the system, taking the standard Landau-Zener model as an example. We calculate the Loschmidt echo(LE) or quantum fidelity in the quantum dynamics under perturbations around the degeneracy, and establish a connection between the LE and the witness of nonlinearity. These phases and Loschmidt echo can be observed with current experimental technology in a nonlinear resonator.
Keywords
Cite
@article{arxiv.0803.3148,
title = {Loschmidt echo and Berry phase around degeneracies in nonlinear systems},
author = {X. X. Yi and X. L. Huang and W. Wang},
journal= {arXiv preprint arXiv:0803.3148},
year = {2009}
}