Generation of Gaussian quantum discord of two bosonic modes in a thermal environment

Abstract

We describe the time evolution of the Gaussian quantum discord of two coupled bosonic modes interacting with a thermal environment, in the framework of the theory of open quantum systems based on completely positive dynamical semigroups. For initial uni-modal squeezed states the generation of Gaussian discord takes place, for all non-zero values of the strength of interaction between the bosonic modes. After reaching some maximum value in the case of initial uni-modal squeezed states, and also for initial squeezed vacuum states with non-zero Gaussian discord, this measure of quantum correlations non-monotonically decreases in time and tends asymptotically for large times to some definite non-zero value.