Canonical band theory of non-collinear magnetism

TL;DR

This paper develops a parameter-free canonical band theory for non-collinear magnetism, explaining magnetic stability and instabilities in crystal structures based on symmetry, exchange splitting, and hybridisation effects.

Contribution

It introduces a novel, symmetry-based band theory for non-collinear magnetism that does not rely on adjustable parameters.

Findings

Explains stability of non-collinear magnetic structures.

Analyzes instability of ferromagnetic states.

Applies to fcc and bcc crystal structures.

Abstract

A canonical band theory of non-collinear magnetism is developed and applied to the close packed fcc and bcc crystal structures. Several examples of non-collinear magnetism in the periodic table are seen to be canonical in origin. This is a parameter free theory where the crystal and magnetic symmetry, and exchange splitting, uniquely determine the electronic bands. The only contribution to the determination of magnetic stability is the change in band energy due to hybridisation resulting from spin mixing, and on this basis we are able to analyse the origin of the stability of non-collinear magnetic structures, and the instability of the FM state towards non-collinear ordering.