Oscillations of Longitudinal Magnetoresistance in Thin Semiconductor Films with a Parabolic Potential Profile

Abstract

This work presents a theoretical investigation of longitudinal magnetoresistance in thin semiconductor films with a parabolic confining potential subjected to a strong quantizing magnetic field. The case of a degenerate electron gas with weak filling of the conduction band is considered. Based on the kinetic equation approach, an analytical expression for the longitudinal electrical conductivity is derived, taking into account the spin splitting of Landau levels. A numerical analysis of the magnetoresistance behavior is carried out for nanostructures based on \(\text{GaAs}\) and \(\text{InSb}\) at a temperature of \(4.2\text{ K}.\) The results demonstrate that quantum oscillations of magnetoresistance arise in such systems, and a negative longitudinal magnetoresistance can occur even under conditions of strong degeneracy. This behavior is attributed to the quantization of electron motion in the transverse direction and the spin splitting of energy levels in a magnetic field. The obtained results indicate that such nanostructures represent promising model systems for investigations in the fields of spintronics and magnetoelectronics.