Quantum discord and Fisher information for two-qubit system in the presence of thermal fields

Abstract

We consider a double Jaynes–Cummings model for a system of two atoms that interact with a radiation field defined in a thermal spin state. We examine the impact of the parameters of the quantum model on the temporal evolution of quantum discord, quantum Fisher information, and fidelity. We explain how the quantifiers can be affected by the thermal noise and spin number with and without the effect of time-dependent coupling. We show that, despite the damaging effects of thermal noise, there is still some amount of discord and Fisher information present during the temporal evolution in accordance with the values of the spin number.