Random Field Driven Spatial Complexity at the Mott Transition in VO2

TL;DR

This study applies critical cluster analysis to VO2's Mott transition, revealing that the geometric properties of metallic and insulating regions align with a random field Ising model near criticality, explaining hysteresis.

Contribution

First application of critical cluster techniques to the Mott transition in VO2, linking geometric properties to a random field Ising model near criticality.

Findings

Geometric properties match the random field Ising model near criticality.

Large energy barriers explain robust hysteresis.

Metal-insulator puddles observed via near-field microscopy.

Abstract

We report the first application of critical cluster techniques to the Mott metal-insulator transition in vanadium dioxide. We show that the geometric properties of the metallic and insulating puddles observed by scanning near-field infrared microscopy are consistent with the system passing near criticality of the random field Ising model as temperature is varied. The resulting large barriers to equilibrium may be the source of the unusually robust hysteresis phenomena associated with the metal-insulator transition in this system.