Entanglement, quantum correlations in a system of the two coupled atoms interacting with a thermal field under intensity-dependent coupling

We study the time evolution behavior of entanglement, the quantum and classical correlations in a system of two coupled two-level atoms interacting with a single mode thermal field. In the model, one atom is in an isolated state and the other is coupled with a small external environment (a single mode thermal field). The effects of mean photon number of thermal field, atom-field coupling strength and intensity-dependent coupling on the evolution processes of the four quantities are analyzed and discussed thoroughly. The results show the sudden deaths and sudden births of various correlations occur and quantum correlation beyond entanglement may be observed in the certain time intervals. It has been seen clearly that the maximal values of various correlations degrade with the increase of mean photon number, atom-field coupling strength and intensity-dependent coupling. The evolution patterns of various correlations are strongly dependent on the about three parameters. Particularly, the time evolution of classical correlation is not consistent with that of quantum correlations during the observed period of time.