Spin-Hall interface resistance in terms of Landauer type spin dipoles

TL;DR

This paper analyzes the spin-Hall interface resistance by examining nonequilibrium spin dipoles around impurities in a 2DEG with Rashba spin-orbit coupling, linking microscopic spin effects to macroscopic boundary phenomena.

Contribution

It introduces a detailed theoretical framework connecting spin dipoles to interface spin-Hall resistance and boundary spin polarization in 2DEG systems.

Findings

Finite local spin polarization around impurities

Zero bulk spin density after averaging

Finite boundary spin polarization related to interface resistance

Abstract

We considered the nonequlibrium spin dipoles induced around spin independent elastic scatterers by the intrinsic spin-Hall effect associated with the Rashba spin-orbit coupling. The normal to 2DEG spin polarization has been calculated in the diffusion range around the scatterer. We found that although around each impurity this polarization is finite, the corresponding macroscopic spin density, obtained via averaging of individual spin dipole distributions over impurity positions is zero in the bulk. At the same time, the spin density is finite near the boundary of 2DEG, except for a special case of a hard wall boundary. The boundary value of the spin polarization can be associated with the interface spin-Hall resistance determining the additional energy dissipation due to spin accumulation.