  The dynamics of an entangled atomic system in a partial interaction with
entangled cavity fields, characterizing an entanglement swapping, have been
studied through the use of Von Neuman entropy. We consider the interaction via
two-photon process given by a full microscopical Hamiltonian approach. The
explicit expression of the entropy is obtained, wherewith we estimated the
largest period. The numerical simulation of the entropy of the entangled atomic
and cavity systems shows that its time evolution presents multi-periodicity.
The effects of detuning parameter on the period and the amplitude of the
entropy are also discussed.
