Spin-dependent scattering effects and dimensional crossover in a quasi-two-dimensional disordered electron system

Two kinds of spin-dependent scattering effects (magnetic-impurity and spin-orbit scatterings) are investigated theoretically in a quasi-two-dimensional (quasi-2D) disordered electron system. By making use of the diagrammatic techniques in perturbation theory, we have calculated the dc conductivity and magnetoresistance due to weak-localization effects, the analytical expressions of them are obtained as functions of the interlayer hopping energy and the characteristic times: elastic, inelastic, magnetic and spin-orbit scattering times. The relevant dimensional crossover behavior from 3D to 2D with decreasing the interlayer coupling is discussed, and the condition for the crossover is shown to be dependent on the aforementioned scattering times. At low temperature there' exists a spin-dependent-scattering-induced dimensional crossover in this system.