Spontaneous emission and cooperative effects near a thin metallic film

Abstract

The set of surface modes propagating in the plane of a thin metallic film and decaying on both sides of the film provide a relaxation channel for excited electric dipoles in the vicinity of the film. The electric field Green functions associated with these localized modes are derived and used to evaluate the decay rates of a single dipole and of a two-dipole system of parallel or orthogonal dipole orientations. The effects of varying the parameters, namely the metallic film, dipole oscillation frequency and dipole position on the decay characteristics are examined. Unfamiliar pair cooperative quantum effects are pointed out, especially when the two dipoles are at close proximity to each other on the same side of the film, or forming an image configuration in which they are reciprocally located at equal distances on different sides of the film. Possible experiments to explore the predictions of the paper are envisaged to make use of the monolayer assembly techniques with LB films as spacers separating polarized molecular layers on the same side or different sides of the metallic film.