The entanglement of two dipole--dipole coupled atoms interacting with a thermal field via a two-photon process

This paper studies entanglement between two dipole--dipole coupled atoms interacting with a thermal field via a two-photon process. It shows that the entanglement is dependent on the mean photon number of the thermal field and the dipole--dipole interaction. The results also show that the atom--atom entanglement through the two-photon process is larger than that through the one-photon process and a remarkable amount of entanglement between the atoms still remains at certain times even for a very highly noisy thermal field.