Entropy and entanglement of the superpositions of displaced Fock states with a two-level atom

The properties of the displaced Fock states (DFS's) superpositions are reviewed. The interaction of these states with a two-level atom in cavity with the presence of additional Kerr medium is studied. Exact general matrix elements of the time-dependent operators of a Jaynes-Cummings model (JCM), in the presence of a Kerr medium, with these states are derived. The atomic inversion and photon number distribution axe discussed. The quantum entropy and the entanglement of the atom-field are investigated. The exact results are employed to perform a careful investigation of the temporal evolution of the entropy. The connection between the field entropy and the collapses and revivals of the atomic inversion has been established. The general conclusions reached are illustrated by numerical results.