Spin-dependent electron-impurity scattering in two-dimensional electron systems

TL;DR

This paper theoretically investigates how charged impurities near a 2D electron gas cause spin-dependent scattering, revealing asymmetries that could lead to Hall-like effects under certain conditions.

Contribution

It demonstrates the symmetry differences in spin-dependent scattering for impurities at different positions and predicts a Hall-like effect due to skew scattering in specific samples.

Findings

Asymmetric skew scattering depends on impurity position relative to the 2D plane.

Spin polarization with a component in the plane can induce skew scattering.

Potential for Hall-like effects in specially prepared samples with in-plane magnetic fields.

Abstract

We present a theoretical study of elastic spin-dependent electron scattering caused by a charged impurity in the vicinity of a two-dimensional electron gas. We find that the symmetry properties of the spin-dependent differential scattering cross section are different for an impurity located in the plane of the electron gas and for one at a finite distance from the plane. We show that in the latter case asymmetric (`skew') scattering can arise if the polarization of the incident electron has a finite projection on the plane spanned by the normal vector of the two-dimensional electron gas and the initial propagation direction. In specially preparated samples this scattering mechanism may give rise to a Hall-like effect in the presence of an in-plane magnetic field.