Influence of dipole-dipole interaction and detuning on the entanglement of two qubits induced by a thermal field

In this paper we have investigated the dynamics of entanglement of two identical qubits nonresonantly interacting with one mode of a thermal electromagnetic field in lossless resonator in the presence of a direct dipole-dipole interaction. On the basis of the exact solution of the considered model, the Peres-Horodetskii entanglement parameter (negativity) for qubits has been found. Numerical simulation of the negativity for various model parameters has been carried out. It has been shown that the interaction of qubits with the thermal field of the resonator can lead to their entanglement. It ha been established that the detuning and dipole-dipole interaction of qubits can be used to manipulate and control the degree of their entanglement.