Origins of thermal spin depolarization in half-metallic ferromagnet CrO$_2$

TL;DR

This study uses high-resolution spectroscopy to explore the origins of thermal spin depolarization in the half-metallic ferromagnet CrO₂, revealing many-body effects and a new depolarization mechanism near the Fermi level.

Contribution

It identifies the many-body effect as the cause of spin depolarization in CrO₂ and highlights a new depolarization process involving minority spin states.

Findings

All spin-polarized electrons contribute to thermal depolarization.

A distinct minority spin state near the Fermi level was observed.

Depolarization is linked to many-body effects in half-metallic ferromagnets.

Abstract

Using high-resolution spin-resolved photoemission spectroscopy, we observed a thermal spin depolarization to which all spin-polarized electrons contribute. Furthermore we observed a distinct minority spin state near the Fermi level and a corresponding depolarization that seldom contributes to demagnetization. The origin of this depolarization has been identified as the many-body effect characteristics of half-metallic ferromagnets. Our investigation opens an experimental field of itinerant ferromagnetic physics focusing on phenomena with sub-meV energy scale.