Strain dependence of bonding and hybridization across the metal-insulator transition of VO2

TL;DR

This study uses soft x-ray spectroscopy to explore how strain affects the electronic and structural properties of VO2 during its metal-insulator transition, revealing strain-sensitive hybridization changes.

Contribution

It uncovers the strain dependence of V 3d - O 2p hybridization in VO2, highlighting the importance of oxygen ions, which is not predicted by existing band theory.

Findings

V 3d - O 2p hybridization varies with strain

Strain influences the structural distortion in VO2

Oxygen ions play a significant role in VO2 physics

Abstract

Soft x-ray spectroscopy is used to investigate the strain dependence of the metal-insulator transition of VO2. Changes in the strength of the V 3d - O 2p hybridization are observed across the transition, and are linked to the structural distortion. Furthermore, although the V-V dimerization is well-described by dynamical mean-field theory, the V-O hybridization is found to have an unexpectedly strong dependence on strain that is not predicted by band theory, emphasizing the relevance of the O ion to the physics of VO2.