Critical Slowing Down at the Abrupt Mott Transition: When the First-Order Phase Transition Becomes Zeroth-Order and Looks Like Second-Order

TL;DR

This paper demonstrates that the abrupt Mott transition in vanadium sesquioxide exhibits critical slowing down and fluctuation enhancement, indicating a critical-like singularity at the spinodal point influenced by strain-induced long-range interactions.

Contribution

It reveals critical phenomena at a first-order Mott transition, showing critical slowing down and fluctuations, and links the transition to a spinodal singularity caused by long-range interactions.

Findings

Critical slowing down observed at the Mott transition.

Enhanced fluctuations indicative of criticality.

Transition controlled by a spinodal singularity.

Abstract

We report that the thermally-induced Mott transition in vanadium sesquioxide shows critical-slowing-down and enhanced variance ('critical opalescence') of the order parameter fluctuations measured through low-frequency resistance-noise spectroscopy. Coupled with the observed increase of also the phase-ordering time, these features suggest that the strong abrupt transition is controlled by a critical-like singularity in the hysteretic metastable phase. The singularity is identified with the spinodal point and is a likely consequence of the strain-induced long-range interaction.