Disentangling structural and electronic properties in V$_{2}$O$_{3}$ thin films: a genuine non-symmetry breaking Mott transition

TL;DR

This study demonstrates a genuine Mott transition in V₂O₃ thin films without symmetry breaking, highlighting purely electronic changes and potential for device applications, distinct from bulk behavior.

Contribution

It provides the first clear evidence of a non-symmetry breaking Mott transition in V₂O₃ thin films, separating electronic and structural effects.

Findings

Genuine Mott transition observed without symmetry breaking.

Spectral evolution is slow over a wide temperature range.

Critical temperature is lower than in bulk V₂O₃.

Abstract

Phase transitions are key in determining and controlling the quantum properties of correlated materials. Here, by using the powerful combination of precise material synthesis and angle resolved photoelectron spectroscopy, we show evidence for a genuine Mott transition undressed of any symmetry breaking side effects in the thin-films of V$_{2}$O$_{3}$. In particular, and in sharp contrast with the bulk V$_{2}$O$_{3}$ crystals, we unveil the purely electronic dynamics approaching the metal-insulator transition, disentangled from the structural transformation that is prevented by the residual substrate-induced strain. On approaching the transition, the spectral signal evolves surprisingly slowly over a wide temperature range, the Fermi wave-vector does not change, and the critical temperature appears to be much lower than the one reported for the bulk. Our findings are on one side fundamental in demonstrating the universal benchmarks of a genuine non-symmetry breaking Mott transition, extendable to a large array of correlated quantum systems and, on the other, given that the fatal structural breakdown is avoided, they hold promise of exploiting the metal-insulator transition by implementing V$_{2}$O$_{3}$ thin films in devices.