Zeeman spin-orbit coupling in antiferromagnetic conductors

TL;DR

This paper reviews Zeeman spin-orbit coupling in antiferromagnetic conductors, highlighting its symmetry origins, differences from intrinsic spin-orbit coupling, and potential experimental signatures.

Contribution

It provides a comprehensive analysis of Zeeman spin-orbit coupling's symmetry properties and its coexistence with intrinsic spin-orbit effects in antiferromagnetic materials.

Findings

Zeeman spin-orbit coupling arises from hidden symmetries protecting degeneracies.

It exhibits a momentum-dependent effective g-factor that vanishes at special points.

Potential experimental signatures include unique responses in magnetic and transport measurements.

Abstract

This article is a brief review of Zeeman spin-orbit coupling, arising in a low-carrier commensurate N\'eel antiferromagnet subject to magnetic field. The field tends to lift the degeneracy of the electron spectrum. However, a hidden symmetry protects double degeneracy of Bloch eigenstates at special momenta in the Brillouin zone. The effective transverse $g$-factor vanishes at such points, thus acquiring a substantial momentum dependence, which turns a textbook Zeeman term into a spin-orbit coupling. After describing the symmetry underpinnings of the Zeeman spin-orbit coupling, I compare it with its intrinsic counterparts such as Rashba coupling, and then show how Zeeman spin-orbit coupling may survive in the presence of intrinsic spin-orbit coupling. Finally, I outline some of the likely experimental manifestations of Zeeman spin-orbit coupling, and compare it with similar phenomena in other settings such as semiconducting quantum wells.