Opposite spin accumulations on the transverse edges by the confining potential

TL;DR

This paper demonstrates that boundary confining potentials induce opposite spin accumulations on transverse edges in a 2D electron gas, with effects robust against disorder and reversing with bias, offering a new explanation for recent experimental observations.

Contribution

It introduces a novel mechanism where boundary confining potentials cause opposite spin accumulations, distinct from bulk spin Hall effects, and remains effective in disordered systems.

Findings

Spin accumulation is proportional to bias voltage.

Opposite spin accumulations occur on transverse edges.

Effect persists despite strong disorder.

Abstract

We show that the spin-orbit interaction induced by the boundary confining potential causes opposite spin accumulations on the transverse edges in a zonal two-dimensional electron gas in the presence of external longitudinal electric field. While the bias is reversed, the spin polarized direction is also reversed. The intensity of the spin accumulation is proportional to the bias voltage. In contrast to the bulk extrinsic and intrinsic spin Hall effects, the spin accumulation by the confining potential is almost unaffected by impurity and survives even in strong disorder. The result provides a new mechanism to explain the recent experimental data.