Fermi Surface of Metallic V$_2$O$_3$ from Angle-Resolved Photoemission: Mid-level Filling of $e_g^{\pi}$ Bands

TL;DR

This study uses ARPES to map the Fermi surface of V$_2$O$_3$, revealing contributions from multiple electronic states and challenging existing theories about its metal-insulator transition mechanism.

Contribution

First ARPES measurement of V$_2$O$_3$'s bulk Fermi surface, showing both $a_{1g}$ and $e_g^{\pi}$ states contribute, questioning prior correlation-based models.

Findings

Observation of electron and hole pockets along the c-axis

Both $a_{1g}$ and $e_g^{\pi}$ bands contribute to the Fermi surface

Results challenge existing crystal field splitting theories

Abstract

Using angle resolved photoemission spectroscopy (ARPES) we report the first band dispersions and distinct features of the bulk Fermi surface (FS) in the paramagnetic metallic phase of the prototypical metal-insulator transition material V$_2$O$_3$. Along the $c$-axis we observe both an electron pocket and a triangular hole-like FS topology, showing that both V 3$d$ $a_{1g}$ and $e_g^{\pi}$ states contribute to the FS. These results challenge the existing correlation-enhanced crystal field splitting theoretical explanation for the transition mechanism and pave the way for the solution of this mystery.