Green function theory of orbital magnetic moment of interacting electrons in solids

TL;DR

This paper derives a general Green function-based formula for the orbital magnetic moment of interacting electrons in solids, enabling better inclusion of exchange and correlation effects beyond standard density functional theory approximations.

Contribution

It introduces a new, comprehensive formula that separates band structure information from exchange and correlation effects for orbital magnetic moments.

Findings

The formula explicitly accounts for electron interactions beyond local density approximation.

It provides a practical framework for incorporating many-body effects in magnetic property calculations.

The approach enhances the accuracy of magnetic moment predictions in complex solids.

Abstract

A general formula for the orbital magnetic moment of interacting electrons in solids is derived using the many-electron Green function method. The formula factorizes into two parts, a part that contains the information about the one-particle band structure of the system and a part that contains the effects of exchange and correlations carried by the Green function. The derived formula provides a convenient means of including the effects of exchange and correlations beyond the commonly used local density approximation of density functional theory.