Spin-orbit interaction in three-dimensionally bounded semiconductor nanostructures

TL;DR

This paper analyzes the spin-orbit interaction in 3D semiconductor nanostructures, considering electric field and composition variations, revealing new terms in wurtzite structures and the interplay of interface and electric field contributions.

Contribution

It introduces a comprehensive analysis of spin-orbit interaction in 3D nanostructures, including new terms in wurtzite semiconductors and the unified treatment of interface and electric field effects.

Findings

Interface and electric field contributions are comparable in strength.

New spin-orbit terms appear in wurtzite quantum wires and dots.

In 2D systems, contributions can partially cancel each other.

Abstract

The structural inversion asymmetry-induced spin-orbit interaction of conduction band electrons in zinc-blende and wurtzite semiconductor structures is analysed allowing for a three-dimensional (3D) character of the external electric field and variation of the chemical composition. The interaction, taking into account all remote bands perturbatively, is presented with two contributions: a heterointerface term and a term caused by the external electric field. They have generally comparable strength and can be written in a unified manner only for 2D systems, where they can partially cancel each other. For quantum wires and dots composed of wurtzite semiconductors new terms appear, absent in zinc-blende structures, which acquire the standard Rashba form in 2D systems.