Friedel phase-shift sum rule for semiconductors

Abstract

The Friedel sum rule relating the phase shifts for scattering by an ion to the charge of the ion is extended to apply to semiconductors by taking nondegenerate statistics and the presence of several types of carriers into account. When the first Born approximation is valid, the phase shifts for the customary screened Coulomb potential obey the sum rule. © 1967 The American Physical Society.