Electrodynamics of an ion near the surface of a conducting dielectric

Abstract

We investigate the electrodynamic phenomena associated with an ion moving near the flat surface of a conducting dielectric solid, where the medium containing the ion has an arbitrary dielectric constant, and the solid has a surface conductivity which is independent of its bulk conductivity. For a fixed ratio of surface to bulk conductance, we show that the frictional drag on the ion is dominated by surface dissipation if the ion is sufficiently close to the surface, while bulk (i.e., ohmic) dissipation is the dominant drag mechanism at large distances. The energy dissipation turns out to be independent of the dielectric constants of the two media, given that dielectric dispersion effects are neglected.