Dispersive Jaynes-Cummings Hamiltonian describing a two-level atom   interacting with a two-level single mode field
  We investigate the time evolution of statistical properties of a single mode radiation field after its interaction with a two-level atom. The entire system is described by a dispersive Jaynes-Cummings Hamiltonian assuming the atomic state evolving from an initial superposition of its excited and ground states, $\vert e\rangle +\vert g\rangle ,$ and the field evolving from an initial superposition of two excited levels, $\vert n_{1}\rangle+ \vert n_{2}\rangle$. It is found that the field evolution is periodic, the period depending on the ratio $n_{2}/n_{1}.$ The energy excitation oscillates between these two states and the statististics can be either sub- or super-Poissonian, depending on the values $n_{1},$ $n_{2}$. 
C.J.S. Ferreira, C. Valverde, and B. Baseia
quant-ph