Electric Pulse Induced Resistive Switching, Electronic Phase Separation, and Possible Superconductivity in a Mott insulator

TL;DR

This paper reports the first experimental evidence of electric pulse-induced insulator-to-metal transition and potential superconductivity in a Mott insulator, driven by nanoscale electronic phase separation observed via STM.

Contribution

It demonstrates a novel method to induce phase transitions in a Mott insulator using electric pulses, revealing new pathways for electronic control.

Findings

Electric pulses induce non-volatile insulator-to-metal transition.

Nanoscale electronic phase separation observed in the bulk.

Potential emergence of superconductivity in the Mott insulator.

Abstract

Metal-insulator transitions (MIT) belong to a class of fascinating physical phenomena, which includes superconductivity, and colossal magnetoresistance (CMR), that are associated with drastic modifications of electrical resistance. In transition metal compounds, MIT are often related to the presence of strong electronic correlations that drive the system into a Mott insulator state. In these systems the MIT is usually tuned by electron doping or by applying an external pressure. However, it was noted recently that a Mott insulator should also be sensitive to other external perturbations such as an electric field. We report here the first experimental evidence of a non-volatile electric-pulse-induced insulator-to-metal transition and possible superconductivity in the Mott insulator GaTa4Se8. Our Scanning Tunneling Microscopy experiments show that this unconventional response of the system to short electric pulses arises from a nanometer scale Electronic Phase Separation (EPS) generated in the bulk material.