Half-metallic ferromagnets: From band structure to many-body effects

TL;DR

This review explores the electronic structure and many-body effects in half-metallic ferromagnets, emphasizing their potential in spintronics and analyzing both theoretical calculations and experimental findings.

Contribution

It provides a comprehensive classification of HMF based on electronic structure, discusses many-body effects like electron-magnon interactions, and reviews state-of-the-art calculations for specific materials.

Findings

Non-quasiparticle states appear in the energy gap of HMF.

Electron-magnon interactions significantly influence magnetic and transport properties.

State-of-the-art electronic calculations reveal complex many-body features in HMF.

Abstract

A review of new developments in theoretical and experimental electronic structure investigations of half-metallic ferromagnets (HMF) is presented. Being semiconductors for one spin projection and metals for another ones, these substances are promising magnetic materials for applications in spintronics (i.e., spin-dependent electronics). Classification of HMF by the peculiarities of their electronic structure and chemical bonding is discussed. Effects of electron-magnon interaction in HMF and their manifestations in magnetic, spectral, thermodynamic, and transport properties are considered. Especial attention is paid to appearance of non-quasiparticle states in the energy gap, which provide an instructive example of essentially many-body features in the electronic structure. State-of-art electronic calculations for correlated $d$-systems is discussed, and results for specific HMF (Heusler alloys, zinc-blende structure compounds, CrO$_{2},$ Fe$_{3}$O$_{4}$) are reviewed.