Spin-Hall Effect in A Symmetric Quantum Wells by A Random Rashba Field

TL;DR

This paper demonstrates that a finite size spin-Hall effect can arise in symmetric quantum wells due to random Rashba spin-orbit coupling caused by dopant ion concentration variations, using advanced numerical methods.

Contribution

It introduces a numerical approach to estimate spin-Hall conductivity in large systems with random Rashba fields in symmetric quantum wells.

Findings

Finite spin-Hall effect observed in symmetric quantum wells.

Numerical estimates align with theoretical predictions.

Method applicable to large-scale quantum systems.

Abstract

Changes dopant ion concentrations in the sides of a symmetric quantum well are known to create a random Rashba-type spin-orbit coupling. Here we demonstrate that, as a consequence, a finite size spin-Hall effect is also present. Our numerical algorithm estimates the result of the Kubo formula for the spin-Hall conductivity, by using a tight-binding approximation of the Hamiltonian in the framework of a time-dependent Green's function formalism, well suited for very large systems.