Entanglement analysis of two-atom nonlinear JCM with nondegenerate   two-photon transition, Kerr nonlinearity and two-mode Stark shift
  Entangled state, as an essential tool in quantum information processing, may be generated through the interaction between light and matter in cavity quantum electrodynamics. In this paper, we study the interaction between two two-level atoms and a two-mode field in an optical cavity enclosed by a medium with Kerr nonlinearity in the presence of detuning parameter and Stark effect. It is assumed that atom-field coupling and third-order susceptibility of the Kerr medium depend on the intensity of light. In order to investigate the dynamics of the introduced system, we obtain the exact analytical form of the state vector of the considered atom-field system under initial conditions which may be prepared for the atoms (in a coherent superposition of their ground and upper states) and the fields (in standard coherent state). Then, in order to evaluate the degree of entanglement between subsystems, we investigate the dynamics of entanglement through the well-known criteria such as von Neumann reduced entropy, entanglement of formation and negativity. Finally, we analyze the influences of Stark shift, deformed Kerr medium, intensity-dependent coupling and also detuning parameter on the above-mentioned measures, in detail. Numerical results show that the amount of entanglement between different subsystems can be controlled by choosing the evolved parameters, appropriately. 
H. R. Baghshahi, M. K. Tavassoly and M. J. Faghihi
quant-ph