Reversible Decoherence of a Mesoscopoic Superposition Driven by a Time-Dependent External Field

By using the normal-ordering technique in the coherent state
representation, we discuss the dynamical evolution of the coherence of a Schrödinger cat state in a high Q cavity coupled to another resonator in the presence of external fields. During the progression of the coherence, We pay particular attention to the effect of the external fields, as well as the initial phase of the Schrödinger cat state,