Local spin polarisation of electrons in Rashba semiconductor nanowires: effects of the bound state

TL;DR

This paper investigates how bound states and Rashba spin-orbit interaction influence local spin polarisation in semiconductor nanowires, revealing robust spin-density islands that could enable local magnetic moments and information storage.

Contribution

It introduces a theoretical analysis of the impact of bound states on local spin polarisation in Rashba nanowires, highlighting the formation of stable spin-density islands.

Findings

High spin-density islands with alternating polarisation signs form inside nanowires.

Spin-density islands caused by structure-induced bound states are robust against disorder.

The study suggests potential for creating local magnetic moments and data storage in semiconductors.

Abstract

The local spin polarisation (LSP) of electrons in two typical semiconductor nanowires under the modulation of Rashba spin-orbit interaction (SOI) is investigated theoretically. The influence of both the SOI- and structure-induced bound states on the LSP is taken into account via the spin-resolved lattice Green function method. It is discovered that high spin-density islands with alternative signs of polarisation are formed inside the nanowires due to the interaction between the bound states and the Rashba effective magnetic field. Further study shows that the spin-density islands caused by the structure-induced bound state exhibit a strong robustness against disorder. These findings may provide an efficient way to create local magnetic moments and store information in semiconductors.