Entanglement in two atom degenerate two photon model

An exact solution of the problem of two two level atoms with degenerate two photon transitions interacting with one mode coherent radiation field is presented. Asymptotic solutions for system state vectors are obtained in the approximation of large initial coherent fields. The atom field entanglement is investigated on the basis of the reduced atomic entropy dynamics. The possibility of the system being initially in a pure disentangled state to revive into this state during the evolution process for model considered is shown. Conditions and times of disentanglement are derived.