Kinetic magnetoelectric effect in a 2D semiconductor strip due to boundary-confinement induced spin-orbit coupling

TL;DR

This paper demonstrates that a longitudinal charge current in a 2D semiconductor strip with boundary-induced spin-orbit coupling causes significant edge spin accumulation, resembling a spin Hall effect, driven by kinetic magnetoelectric phenomena.

Contribution

It reveals a novel kinetic magnetoelectric effect in 2D semiconductors caused by boundary-confinement induced spin-orbit coupling, highlighting a new mechanism for spin accumulation.

Findings

Strong non-equilibrium spin accumulation at edges

Opposite spin polarization directions at edges

Resembles spin Hall effect phenomena

Abstract

In a thin strip of a two-dimensional semiconductor electronic system, spin-orbit coupling may be induced near both edges of the strip due to the substantial spatial variation of the confining potential in the boundary regions. In this paper we show that, in the presence of boundary-confinement induced spin-orbit coupling, a longitudinal charge current circulating through a 2D semiconductor strip may cause \textit{strong} non-equilibrium spin accumulation near both edges of the strip. The spins will be polarized along the normal of the 2DEG plane but in opposite directions at both edges of the strip. This phenomenon is essentially a kinetic magnetoelectric effect from the theoretical points of view, but it manifests in a very similar form as was conceived in a spin Hall effect.