Dynamics of a single-mode field interacting with a Λ-type three-level atom

In this work, the time evolution of the entropy of a single-mode field interacting with a Λ-type degenerate quantum beat three-level atom is investigated in the strong field limit. The field is assumed to be prepared in a coherent state. The results show that the initial atomic state and the detuning of the field play important roles in the evolution of the field entropy and the generation of a Schrödinger cat state at the half-revival time of the atomic inversion needs strict conditions. The squeezing properties of the field are also explored, and some new conclusions are obtained.