Properties of the field entropy evolution in two-photon Jaynes-Cummings model

The properties of the field entropy evolution in the two-photon Jaynes-Cummings model (JCM) with the atoms being at coherent superposition states and the field being at coherent state are studied. When atoms are always at coherent superposition states and atomic initial states are excited or at ground state, at the same time the field is at coherent state, the properties of the field entropy evolve with respect to time. Furthermore, the optical field couples with atoms in the JCM, the properties of the field entropy evolve when ω₀ is equal to 2ω and state vector is any time. The influences of the average photon numbers of the initial optical field n̄ and coupling constant g on the evolution of the field entropy are also discussed through expressions and figures.