In this paper, we investigate the temporal evolution of various measures of
degree of entanglement and total correlation of a single-mode light field
interacting with a two-level atom. The phase-damped cavity is taken into
account. The effects of phase damping on a temporal of partial entropies
for the atom and the field, total entropy, the entropy difference and the
sum of negative eigenvalues of the partially transposed density matrix as a
quantitative entanglement measure for the master equation in the dressed-state
approximation are taken into account.