Temperature dependence of the electronic structure and Fermi-surface reconstruction of Eu(1-x)Gd(x)O through the ferromagnetic metal-insulator transition

TL;DR

This study uses angle-resolved photoemission spectroscopy to investigate how the electronic structure and Fermi surface of Eu(1-x)Gd(x)O change with temperature across the ferromagnetic metal-insulator transition, revealing momentum-dependent electronic evolution.

Contribution

It provides detailed experimental insights into the temperature-dependent electronic structure and Fermi surface reconstruction in Eu(1-x)Gd(x)O, highlighting the role of magnetic order.

Findings

Fermi surface pockets at the zone boundary in the ferromagnetic phase

Pseudogapped states at the zone center in the paramagnetic phase

Strong momentum-dependent evolution of electronic states

Abstract

We present angle-resolved photoemission spectroscopy of Eu(1-x)Gd(x)O through the ferromagnetic metal-insulator transition. In the ferromagnetic phase, we observe Fermi surface pockets at the Brillouin zone boundary, consistent with density functional theory, which predicts a half metal. Upon warming into the paramagnetic state, our results reveal a strong momentum-dependent evolution of the electronic structure, where the metallic states at the zone boundary are replaced by pseudogapped states at the Brillouin zone center due to the absence of magnetic long-range order of the Eu 4f moments.