Electrodynamics at a metal surface with applications to the spectroscopy of adsorbed molecules. I. General theory

Abstract

Recently, a large number of surface-spectroscopic phenomena have been discussed in terms of models which provide phenomenological equations for the response of the adsorbed molecule to the external fields and compute these fields by assuming that the macroscopic Maxwell equations are valid. Since the macroscopic equations neglect the spatial dispersion of the dielectric constant of the metal and its variation with the distance to the surface, one expects that the computation of the field near or inside the interface may have substantial errors. In order to study the extent of such errors, we use a jellium-electron-gas model to develop a microscopic theory of the electromagnetic fields at the interface. The electron-gas properties needed in such calculations are obtained by using the random-phase approximation. Numerical results are planned to be presented in future papers.