Quantum Discord and Entanglement between two two-level atoms interacting with a nondegenerate parametric amplifier

Entanglement and Discord are highly complex phenomenon, and of great importance in quantum theory because of its various applications in quantum information processing. Because of this, here, we study and analyze both of them according to two coupled two-level atoms with two coupled quantized fields in the form of a non-degenerate parametric amplifier type in a cavity. We compare and analyze the effect of temperature, atom-atom and Kerr–type couplings in quantum discord and entanglement between the atoms. As a result, it has been shown that the quantum discord decrease asymptotically to zero when temperature increase. The results also indicate that entanglement suddenly disappears during the evaluation, but quantum discord remains non zero. Then the quantum discord is considered as indicator of disentanglement.