Nonclassical Correlation Dynamics in a System of Mesoscopic Josephson Junction Coupled to Single-mode Optical Cavity

Abstract

We investigate the time evolutions of the continuous-variable entanglement and Gaussian quantum discord in a system consisting of a mesoscopic Josephson junction coupled to a single-mode optical cavity field. We can obtain the time-dependent covariance matrix using known symplectic operation and local canonical transformations. We compare the dynamics of Gaussian quantum discord with that of entanglement. It is shown that the entanglement dynamics of two-mode squeezed thermal state is richer and undergoes three different features: periodical oscillation, sudden death and revival, and no-creation of entanglement, conditioned on the average number of thermal photons in each mode, whereas the Gaussian quantum discord can only exhibit a periodical oscillation behavior during the evolution.