Entanglement and preparation for an atom interacting with two-mode coherent strong field via intensity-dependent coupling multiphoton processes

Abstract

In this paper, effective Hamiltonian of the two-mode multiphoton Jaynes-Cummings model is given via the intensity-dependent coupling in the rotating wave approximation. Under strong field, the atom-field entanglement and the entanglement between two modes of coherent field, according to the above model, are investigated by using the quantum reduced entropy and the quantum relative entropy, respectively. It is showed that properties of these two types of entanglements are considerably relevant to the absorption or emission photon number k, per atomic transition. Different properties of entanglements in the processes of two-photon (k=1) and mutiphoton (k>2) are revealed respectively. The preparation of entangled states is discussed. The Einstein-Podolsky-Rosen states of atom-field irrelevant to time, as well as entangled states between two models of the coherent field are prepared, respectively.