The nonclassical properties such as antibunching effect,violation of Cauchy-Schwarz inequality and two-mode squeezing of the pair coherent states based on a non-degenerate two-photon Jaynes-Cummings model were investigated.It is shown that these nonclassical properties can be enhanced in the case that the coefficients are chosen appropriately or the atom is selectively detected.In addition,all kinds of the nonclassical properties by using(?)-type three-level atom are more effective than that using i4-type three-level atom.
The dynamics of the driven Jaynes-Cummings model where a two-level atom is coupled to a single mode of cavity fields and is driven by an external coherent field is investigated. We find that in this model quantum collapse and revivals of the atomic population inversion and squeezing of the cavity field can be generated from a thermal photon state. We also notice that the squeezing is very sensitive to the mean number of thermal photons initially in the cavity, but the quantum collapse and revivals are not. The influence of the amplitude of the driving field and various detuning parameters on the nonclassical effects is discussed. The result shows that one can use the external field to control nonclassical effects in the Jaynes-Cummings model.