Dielectric properties of a thin film consisting of a few layers of molecules or particles

Abstract

An accurate model for the dielectric properties of a thin film consisting of a few layers of particles (or molecules) is described. The depth dependence and the anisotropic behavior of the local permittivity due to the surface environment are studied. The method is described in terms of a general multipole expansion, but the detailed derivation is carried out mainly in the framework of dipole approximation for the field interactions of particles. Both the static and harmonic cases are considered. Numerical results are presented.