Nature of Spin Hall Effect in a finite Ballistic Two-Dimensional System with Rashba and Dresselhaus spin-orbit interaction

TL;DR

This paper numerically investigates the spin Hall effect in a finite ballistic 2D system with Rashba and Dresselhaus interactions, revealing its sensitivity to device parameters and non-universality unlike charge Hall effects.

Contribution

It demonstrates the non-universal behavior of the spin Hall conductance, showing dependence on device shape, size, and measurement location, and attributes this to extended eigenstates.

Findings

Spin Hall conductance varies with measurement location, shape, and size.

The sign of spin Hall conductance can change under different conditions.

Eigenstates are extended, not forming edge states, affecting conductance behavior.

Abstract

The spin Hall effect in a finite ballistic two-dimensional system with Rashba and Dresselhaus spin-orbit interaction is studied numerically. We find that the spin Hall conductance is very sensitive to the transverse measuring location, the shape and size of the device, and the strength of the spin-orbit interaction. Not only the amplitude of spin Hall conductance but also its sign can change. This non-universal behavior of the spin Hall effect is essentially different from that of the charge Hall effect, in which the Hall voltage is almost invariant with the transverse measuring site and is a monotonic function of the strength of the magnetic field. These surprise behavior of the spin Hall conductance are attributed to the fact that the eigenstates of the spin Hall system is extended in the transverse direction and do not form the edge states.