Decay Rate of an Excited Atom in Dispersive and Dissipative Plasma Media

Calculations of decay rates of an excited atom embedded in a dispersive and dissipative plasma medium are presented in this paper. The usual expression for decay rate of an initially excited atom in dipole approximation is given by Fermi’s golden rule. The electric field correlation function is related to the imaginary part of the potential Green’s function along with the fluctuation of dissipation theorem and Kubo’s formula. Using the Green’s function technique offers possibilities of closed function representations. It is applicable to evaluate the decay rate of an excited atom that allows us to understand the particular structure of the vacuum state of the electromagnetic field. In this paper, the decay rate of an excited atom in dispersive and dissipative media is estimated.