Electric-field-driven phase transition in vanadium dioxide

TL;DR

This study demonstrates that an electric field alone can induce the insulator-to-metal transition in VO2 thin films, with local probe measurements revealing threshold behavior and noise characteristics.

Contribution

It provides direct local measurements of electric-field-induced phase transition in VO2, highlighting the role of electric field and electronic feedback in the transition mechanism.

Findings

Transition occurs at electric field ~6.5×10^7 V/m at 300K.

Transition can be observed via electrostatic force and tunneling current.

Random telegraphic noise observed in noncontact regime.

Abstract

We report on local probe measurements of current-voltage and electrostatic force-voltage characteristics of electric-field-induced insulator to metal transition in VO2 thin film. In conducting AFM mode, switching from the insulating to metallic state occurs for electric-field threshold E~6.5\times10^7 Vm-1 at 300K. Upon lifting the tip above the sample surface, we find that the transition can also be observed through a change in electrostatic force and in tunneling current. In this noncontact regime, the transition is characterized by random telegraphic noise. These results show that electric field alone is sufficient to induce the transition; however, the electronic current provides a positive feedback effect that amplifies the phenomena.