Band-spin-orbit-energy effects in conductivity of two-dimensional weakly disordered semiconductor systems

Abstract

Effects of conduction-band splitting caused by the spin-orbit interaction on the magnetoresistance in strict two-dimensional disordered semiconductor systems are considered. The Dyakonov-Perel' process (the randomization of spin precession due to elastic scattering) is assumed to be the dominant spin-dephasing mechanism. Unlike results published previously, which turned out to be wrong, new expressions for the weak-localization corrections to the conductivity under an applied magnetic field are derived. The field dependence of the conductivity is proved to be of variable sign like that of metal films. The explicit forms of the correction are, however, markedly different from those known for the impurity spin-orbit scattering. Both cases-the perpendicular and parallel magnetic field, where an account of Zeeman splitting is necessary-are discussed.