Interference mechanism of magnetoresistance in variable range hopping conduction: the effect of paramagnetic electron spins and continuous spectrum of scatterer energies

TL;DR

This paper develops a comprehensive theory of magnetoresistance in hopping conduction semiconductors, explicitly accounting for free and frozen electron spins and scatterer energy dispersion, aligning with experimental observations.

Contribution

It introduces a new theoretical model that includes free electron spins and energy spectrum effects, extending previous spinless electron models.

Findings

The model explains magnetoresistance behavior considering free spins.

Inclusion of scatterer energy dispersion improves experimental data fit.

Results highlight the significance of free spins in hopping conduction magnetoresistance.

Abstract

Despite the fact that the problem of interference mechanism of magnetoresistance in semiconductors with hopping conductivity was widely discussed, most of existing studies were focused on the model of spinless electrons. This model can be justified only when all electron spins are frozen. However there is always an admixture of free spins in the semiconductor. This study presents the theory of interference contribution to magnetoresistance that explicitly includes effects of both frozen and free electron spins. We consider the cases of small and large number of scatterers in the hopping event. For the case of large number of scatterers the approach is used that takes into account the dispersion of the scatterer energies. We compare our results with existing experimental data.