Electric-Field-Induced Resistive Switching in a Family of Mott Insulators : towards Non-Volatile Mott-RRAM Memories

TL;DR

This paper demonstrates electric-field-induced resistive switching in Mott insulators, enabling potential non-volatile memory devices with fast operation and significant resistance change at room temperature.

Contribution

It introduces a new resistive switching mechanism in Mott insulators driven by electric fields, suitable for non-volatile Mott-RRAM memory applications.

Findings

Electric fields as low as 2 kV/cm induce insulator-metal transition.

Switching between high and low resistance states with short pulses.

Potential for fast, room-temperature non-volatile memory devices.

Abstract

The fundamental building blocks of modern silicon-based microelectronics, such as double gate transistors in non-volatile Flash memories, are based on the control of electrical resistance by electrostatic charging. Flash memories could soon reach their miniaturization limits mostly because reliably keeping enough electrons in an always smaller cell size will become increasingly difficult . The control of electrical resistance at the nanometer scale therefore requires new concepts, and the ultimate resistance-change device is believed to exploit a purely electronic phase change such as the Mott insulator to insulator transition [2]. Here we show that application of short electric pulses allows to switch back and forth between an initial high-resistance insulating state ("0" state) and a low-resistance "metallic" state ("1" state) in the whole class of Mott Insulator compounds AM4X8 (A = Ga, Ge; M= V, Nb, Ta; X = S, Se). We found that electric fields as low as 2 kV/cm induce an electronic phase change in these compounds from a Mott insulating state to a metallic-like state. Our results suggest that this transition belongs to a new class of resistive switching and might be explained by recent theoretical works predicting that an insulator to metal transition can be achieved by a simple electric field in a Mott Insulator. This new type of resistive switching has potential to build up a new class of Resistive Random Access Memory (RRAM) with fast writing/erasing times (50 ns to 10 {\mu}s) and resistance ratios \Delta R/R of the order of 25% at room temperature.