Green-function theory of spontaneous emission and cooperative effects in asuperlattice of thin metal layers - art. no. 063812

Real-space electric-field Green functions are derived for a superlattice st ructure composed of a regular array of thin metal films immersed in a diele ctric. The derivation makes use of the jump condition on the magnetic field due to the areal conductivity of the metal and conforms with Bloch's theor em on the one-dimensional periodicity of the structure along the growth dir ection. The initial steps lead to mixed (real-space-reciprocal-space) Green functions. We show how the desired all-space Green functions are obtainabl e from these by Fourier transformation to real space, making use of the sym metry properties of the system. The emission rate for a dipole of a given o rientation follows directly from the imaginary part of the appropriate equa l-spare Green function. The results are investigated for different electron densities and different periodicity lengths and compared with the results appropriate for a single sheet and various asymptotic limits. Also using th e same set of Green functions, we determine pair cooperative effects for di poles embedded in the structure. Interesting features are pointed out when the dipoles have different orientations and/or are situated in different un it cells of the superlattice.