Kinetic Spinodal Instabilities in the Mott Transition in V2O3: Evidence from Hysteresis Scaling and Dissipative Phase Ordering

TL;DR

This paper demonstrates that the thermally induced Mott transition in V2O3 exhibits critical dynamics and spinodal-like instabilities, with hysteresis scaling consistent with mean field predictions, challenging classical nucleation theory.

Contribution

It provides the first systematic evidence of hysteresis scaling and spinodal-like behavior in a real correlated electron system during a first-order phase transition.

Findings

Hysteresis depth scales with temperature scan rate.

Dynamic scaling exponent close to 2/3, mean field prediction.

Evidence of barrier-free phase ordering and critical dynamics.

Abstract

We present the first systematic observation of scaling of thermal hysteresis with the temperature scanning rate around an abrupt thermodynamic transition in correlated electron systems. We show that the depth of supercooling and superheating in vanadium sesquioxide (V2O3) shifts with the temperature quench rates. The dynamic scaling exponent is close to the mean field prediction of 2/3. These observations, combined with the purely dissipative continuous ordering seen in "quench-and-hold" experiments, indicate departures from classical nucleation theory toward a barrier-free phase ordering associated with critical dynamics. Observation of critical-like features and scaling in a thermally induced abrupt phase transition suggests that the presence of a spinodal-like instability is not just an artifact of the mean field theories but can also exist in the transformation kinetics of real systems, surviving fluctuations.