Inequivalent routes across the Mott transition in V2O3 explored by X-ray absorption

TL;DR

This study reveals that the metallic phase of V2O3 differs depending on whether the Mott transition is induced by temperature, doping, or pressure, challenging previous assumptions of their equivalence.

Contribution

The paper demonstrates that different routes across the Mott transition in V2O3 lead to inequivalent metallic phases, using high-resolution X-ray absorption spectroscopy and a novel computational approach.

Findings

Pressure-induced metallic phase differs from doping- or temperature-induced phases

Role and occupancy of a1g orbitals are key to understanding the transition

Different transition pathways result in distinct electronic structures

Abstract

The changes in the electronic structure of V2O3 across the metal-insulator transition induced by temperature, doping and pressure are identified using high resolution x-ray absorption spectroscopy at the V pre K-edge. Contrary to what has been taken for granted so far, the metallic phase reached under pressure is shown to differ from the one obtained by changing doping or temperature. Using a novel computational scheme, we relate this effect to the role and occupancy of the a1g orbitals. This finding unveils the inequivalence of different routes across the Mott transition in V2O3