Abstract

The quantum reflectivity of a randomly rough surface in the presence of a uniform magnetic field parallel to the mean surface is approximately calculated. The resulting specularity function-depending on the RMS roughness amplitude, the lateral correlation length, the angle of incidence of a conduction electron and the angle between its classical trajectory and the magnetic field-is used in conjunction with the Boltzmann equation in order to calculate the magnetoresistance of thin films as a function of field strength and thickness. For intermediate fields, the authors find considerable disagreements between these results and the usual theory in which the surface specularity is represented by a phenomenological parameter.