QUANTUM-LIMIT MAGNETORESISTANCE FOR IMPURITY SCATTERING

The theoretical formalism for calculating the magnetotransport effects developed by Arora and Peterson is extended to include the effects of anisotropic screened ionized impurity scattering in nondegenerate semiconductors in the quantum limit when ħωc ≫ kBT. Screening is found to be negligible at high magnetic fields for the transverse magnetoresistance. It is found that for point defect scattering, both the longitudinal and transverse magnetoresistance are linear in the magnetic field, whereas the Hall coefficient differs from its high field value 1/encc by a temperature dependent factor which is found to be close to unity. For ionized impurity scattering, the longitudinal magnetoresistance is found to be independent of the magnetic field, whereas the transverse magnetoresistance and the Hall coefficient decrease with magnetic field, the former as B−1, where B is the magnetic field. For combined acoustic phonon and ionized impurity scattering, the acoustic phonon scattering is found to dominate at very high magnetic fields giving rise to the ex‐perimentally observed linear magnetoresistance. The combination of acoustic phonon and point defect scattering also yields similar results. Copyright © 1979 WILEY‐VCH Verlag GmbH & Co. KGaA