STUDY OF NONCLASSICAL FEATURES AND QUANTUM DYNAMICS IN THE JAYNES-CUMMINGS MODEL WITHOUT RWA

Some nonclassical features, including photon antibunching, atomic sque ezing and quantum collapse-revival phenomenon, were numerically studie d is the vacuum held Jaynes-Cummings model (JCM). The influence of the initial atomic coherence on these features was discussed. It is shown that the squeezing can appear only if the atom is initially prepared in the coherent state, and photon antibunching can occur if the atom i s initially in the excited state or the coherent one. The effect of th e virtual-photon field was studied in JCM without the rotating-wave ap proximation (RWA). We have shown that even under the condition in whic h RWA is considered to be valid, there are significant effects on the nonclassical features due to the interference between the virtual-phot on processes and the real-photon processes. Quantum dynamics of JCM wi thout RWA was also studied. We showed that regular dynamical behavior is exhibited in the cases rather close to the integrable limits, and i rregular dynamical behavior is presented in the cases far from the int egrable limits; in addition, all the nonclassical features disappear i n the cases far from the integrable limits.