Non-Thermal Resistive Switching in Mott Insulators

TL;DR

This paper investigates resistive switching in Mott insulators, revealing a universal, low-energy, non-thermal mechanism driven by electric fields, with potential for energy-efficient memory and neuromorphic devices.

Contribution

It identifies two regimes of resistive switching in Mott insulators and demonstrates control over the non-thermal switching mechanism via focused ion-beam irradiation.

Findings

Distinction between Joule heating and field-assisted switching regimes

Development of a universal switching mechanism model

Achievement of low-energy, non-thermal resistive switching

Abstract

Resistive switching can be achieved in a Mott insulator by applying current/voltage, which triggers an insulator-metal transition (IMT). This phenomenon is key for understanding IMT physics and developing novel memory elements and brain-inspired technology. Despite this, the roles of electric field and Joule heating in the switching process remain controversial. We resolve this issue by studying nanowires of two archetypical Mott insulators - VO2 and V2O3. Our findings show a crossover between two qualitatively different regimes. In one, the IMT is driven by Joule heating to the transition temperature, while in the other, field-assisted carrier generation gives rise to a doping driven IMT which is purely non-thermal. By identifying the key material properties governing these phenomena, we propose a universal mechanism for resistive switching in Mott insulators. This understanding enabled us to control the switching mechanism using focused ion-beam irradiation, thereby facilitating an electrically driven non-thermal IMT. The energy consumption associated with the non-thermal IMT is extremely low, rivaling that of state of the art electronics and biological neurons. These findings pave the way towards highly energy-efficient applications of Mott insulators.