Control of quantum information flow and quantum correlations in the two-atom Tavis–Cummings model

Abstract

We investigate the quantum information of the two non-interacting two-level atoms coupled to a single mode of the cavity field via selective measurements. It is found that the information of the two atoms can be protected by intensive measurements and can be enhanced by a single measurement which is demonstrated by the growth of the trace distance between two marginal states of the two atoms, as well as the positive information flow in the first instance. We also show that the single measurement is effective for enhancing the quantum information flow, which leads to the increase of quantum correlations including concurrence and quantum discord. Moreover, we explore the behaviour of total information measured by the trace distance when the total system is initially in its thermal equilibrium state and how the atom–cavity coupling and the temperature affect the total correlation for the thermal state of the entire system.