Modeling and physically interpreting dissipative dynamics of a charge qubit–atom hybrid system under the Born–Markov limit

Abstract

In this study, we model the dissipative dynamics of a charge qubit–atom hybrid model under the Born–Markov limit. Especially, we focus on the physical relation between spectral density and dissipative dynamics. Analytically, we show that, if spectral density in the dynamics is a nearly linear function, then relaxation and dephasing noises separately affect the gate capacitor and Josephson junction, respectively, but if the spectral density is a genuine-nonlinear function, then these two noises affect both the gate capacitor and Josephson junction. Further, we observe that in a numerical way, when the spectral density is a genuine-nonlinear function, there are some cases in which the corresponding environment dramatically breaks quantumness including purity and entanglement.