Non-classicality dynamics of Schrödinger cat states in a non-Markovian environment

Abstract

By virtue of the superoperator technique, we solve analytically the non-Markovian master equation that describes single-mode continuous variable system interacting with a structure reservoir. Our analytical solution allows us to investigate the non-Markovian effects on the dynamics of quantum coherence and non-classicality of Schrödinger cat states embedded in various types of structured reservoirs. We show that the dynamical behaviors of the fidelity, entanglement potentials, and higher-order antibunching of such states can be divided into two phases: they decay rapidly within a short time, but would either vanish completely or tend to a nonzero steady-state value in the long-time limit depending on the initial Schrödinger cat states and system parameters. We also show that by examining the Wigner function and higher-order sub-Poissonian statistics, the super-Ohmic environment can better help to protect the non-classicality, whereas the sub-Ohmic environment causes the disappearance of the non-classicality. Our approach is concise and can generalize to other open quantum system coupled to non-Markovian environment at finite-temperature or to linear non-Markovian Gaussian system.