Current induced local spin polarization due to the spin-orbit coupling in a two dimensional narrow strip

TL;DR

This paper investigates how weak Rashba spin-orbit coupling in a narrow 2D strip causes local spin polarization under current, highlighting size-dependent effects and distinguishing from bulk spin-Hall phenomena.

Contribution

It provides a detailed analysis of current-induced local spin polarization in narrow strips, emphasizing the size dependence and the distinction from bulk spin-Hall effects.

Findings

Out-of-plane spin polarization appears mainly in mesoscopic systems.

In-plane spin polarization does not change sign across the sample.

Out-of-plane polarization is not directly related to bulk spin-Hall effect.

Abstract

The current induced local spin polarization due to weak Rashba spin-orbit coupling in narrow strip is studied. In the presence of longitudinal charge current, local spin polarizations appear in the sample. The spin polarization perpendicular to the plane has opposite sign near the two edges. The in-plane spin polarization in the direction perpendicular to the sample edges also appears, but does not change sign across the sample. From our scaling analysis based on increasing the strip width, the out-of-plane spin polarization is important mainly in a system of mesoscopic size, and thus appears not to be associated with the spin-Hall effect in bulk samples.