  The effect of retardation in the atom-field interaction on the dynamics of
entanglement in a double Jaynes-Cummings system is investigated. We consider
large cavities in which a finite time necessary for light to travel between the
atoms and the cavity mirrors may result in retardation effects. Our results
demonstrate the qualitatively new behaviour observable in the time evolution of
entanglement when the retardation effects are included. Solutions for single
and double excitation in the system are presented. We follow the temporal
evolution of an initial entanglement and find that the evolution is affected
drastically by the retardation effects. In particular, the harmonic
oscillations of the atomic populations and the concurrence, characteristic of
single-mode Jaynes-Cummings systems, are suppressed when the retardation
effects are included. The process of revival of the entanglement degrades with
an increasing number of the cavity modes to which the atoms are coupled. It is
also found that the effect of the retardation on the doubly excited states is
more drastic than on the single excitation states that at relatively short
times, the retardation leads to a complete distortion of entanglement carried
by a doubly excited state.
