The effect of the spin-orbit interaction on the band gap of half-metals

TL;DR

This paper investigates how spin-orbit interaction influences the electronic properties of half-metals, revealing that it introduces a non-zero density of states within the band gap, with effects varying across different materials.

Contribution

It provides a first-principles analysis of the magnitude of spin-orbit effects on the density of states in various half-metallic materials.

Findings

Spin-orbit interaction causes a non-zero DOS within the band gap.

The DOS ratio varies significantly among different materials.

In NiMnSb, the ratio is below 1%, while in MnBi, it reaches 13%.

Abstract

The spin-orbit interaction can cause a nonvanishing density of states (DOS) within the minority-spin band gap of half-metals around the Fermi level. We examine the magnitude of the effect in Heusler alloys, zinc-blende half metals and diluted magnetic semiconductors, using first-principles calculations. We find that the ratio of spin-down to spin-up DOS at the Fermi level can range from below 1% (e.g. 0.5% for NiMnSb) over several percents (4.2% for (Ga,Mn)As) to 13% for MnBi.