Edge-induced spin polarization in two-dimensional electron gas

TL;DR

This paper investigates how spin-orbit coupling at the edges of a 2D electron gas induces spin polarization, deriving a simple analytical expression that is robust across various edge potentials and densities, with implications for spintronic devices.

Contribution

It provides an analytical characterization of edge-induced spin polarization in 2D electron gases, showing independence from edge potential details and electronic density.

Findings

Spin polarization magnitude is independent of edge potential and density.

The effect's spatial extent is limited to about 10nm, near the Fermi wavelength.

The amplitude is comparable to extrinsic spin Hall effect values.

Abstract

We characterize the role of the spin-orbit coupling between electrons and the confining potential of the edge in nonequilibrium 2D homogeneous electronic gas. We derive a simple analytical result for the magnitude of the current induced spin polarization at the edge and prove that it is independent of the details of the confinement edge potential and the electronic density within realistic values of the parameters of the considered models. While the amplitude of the spin accumulation is comparable to the experimental values of extrinsic spin Hall effect in similar samples, the spatial extent of edge induced effect is restricted to the distances of the order of Fermi wavelength ($\sim$ 10nm).