Non-quasiparticle states in a half-metallic ferromagnet with antiferromagnetic $s-d(f)$ interaction

TL;DR

This paper investigates non-quasiparticle states in half-metallic ferromagnets with antiferromagnetic s-d(f) interaction, offering a new approach to their description in strong correlation regimes and addressing the Kondo problem.

Contribution

It introduces a novel method for describing non-quasiparticle states in HMFs with antiferromagnetic exchange, improving upon traditional perturbation approaches.

Findings

Provides a solution to the Kondo problem in HMFs.

Highlights the importance of rearranged perturbation series for strong correlations.

Suggests implications for first-principle calculations of ferromagnetic materials.

Abstract

Non-quasiparticle (incoherent) states which play an important role in the electronic structure of half-metallic ferromagnets (HMF) are investigated consistently in the case of antiferromagnetic $s-d(f)$ exchange interaction. Their appropriate description in the limit of strong correlations requires a rearrangement of perturbation series in comparison with the usual Dyson equation. This consideration provides a solution of the Kondo problem in the HMF case and can be important for first-principle HMF calculations performed earlier for ferromagnetic $s-d(f)$ interaction.