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

Abstract

In a thin strip of a two-dimensional (2D) 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 strong nonequilibrium spin accumulation near both edges of the strip, and the nonequilibrium spin accumulation will be polarized perpendicular to the two-dimensional electron gas plane but along 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.