DISSIPATION IN COLLECTIVE INTERACTIONS

An approximate solution is given for the interaction of a set of A two -level atoms with a single mode of a quantized radiation field when th e field is damped by a reservoir at zero temperature. Assuming that th e average photon number is much larger than the number of atoms, we st udy the influence of dissipation on the approximate factorization of t he density matrix. For realistic values of the parameters, the factori zation survives under the presence of field damping. The main effect o f dissipation is an exponential decay of the average photon number and a loss of coherence among the different factorized states. The influe nce of field dissipation on the atomic inversion, purity, and field sq ueezing are studied. [S1050-2947(98)07210-2].