Photoemission evidence for crossover from Peierls-like to Mott-like transition in highly strained VO$_2$

TL;DR

This study uses spectroscopy to show that applying strain to VO$_2$ thin films can induce a transition from a lattice-driven Peierls-like insulator to an electronically driven Mott-like insulator, revealing a crossover in transition mechanisms.

Contribution

It provides spectroscopic evidence of a strain-induced crossover from Peierls-like to Mott-like metal-insulator transitions in VO$_2$ thin films, highlighting the role of electronic correlations.

Findings

Strain can suppress Peierls dimerization in VO$_2$.

Spectroscopy indicates a transition to a purely electronic Mott insulator.

Crossover from lattice-driven to electronically driven transition observed.

Abstract

We present a spectroscopic study that reveals that the metal-insulator transition of strained VO$_2$ thin films may be driven towards a purely electronic transition, which does not rely on the Peierls dimerization, by the application of mechanical strain. Comparison with a moderately strained system, which does involve the lattice, demonstrates the crossover from Peierls- to Mott-like transitions.