Theory of the Anomalous Skin Effect in a Metal Film. II. —Anomalous Penetration into Normal and Superconducting Films—

Abstract

Anomalous penetration of electromagnetic waves through a metal film (thickness L) in the absence of a static magnetic field is studied. The characteristics of the penetration depend in an essential way on the structures of the Fermi surface. In particular, the phase of the transmitted wave takes the form exp(iωL⁄u) with u an extremum electron velocity normal to the film. Diffuse scattering of electrons at the film surfaces enhances the penetration remarkably. The same problem in a type-I superconductor is also studied. For k_BT<<Δ<<hω, the anomalous penetration is produced by pairs of excitations, and the phase is given by exp[i(ωL⁄u)×{1−2(Δ⁄hω)²}]. Anomalous penetration of a static magnetic field into a metal in the normal and superconducting state is considered in passing. Besides quantum oscillations which are a magnetic analogue to the Friedel oscillations, there appears in the superconducting state a different component produced by the correlation between pairs of electrons.