Umklapp surface reflection of conduction electrons

Abstract

The specular reflection of conduction electrons is limited, even at an ideal metal surface, by a mechanism suggested by Price. This process, loosely called umklapp surface scattering, is studied theoretically in this paper. The grazing-incidence behavior is analyzed, and special singularities in the reflection coefficients are predicted. The singularities are related in a simple manner to the Fermi-surface geometry. The results appear relevant to experiments on magnetic surface-state resonance, the anomalous skin effect, and the thin-film size effect. The umklapp mechanism is interesting especially because it represents an intrinsic limit on specular reflection which cannot be removed by cleaning and polishing the specimen.