Light-Assisted Resistance Collapse in a V2O3 -Based Mott-Insulator Device

Abstract

The insulator-to-metal transition in Mott insulators is the key mechanism for most of the electronic devices belonging to the Mottronics family. Intense research efforts are currently devoted to the development of specific control protocols, usually based on the application of voltage, strain, pressure, and light excitation. The ultimate goal is to achieve the complete control of the electronic phase transformation, with dramatic impact on the performance, for example, of resistive-switching devices. Here, we investigate the simultaneous effect of external voltage and excitation by ultrashort light pulses on a single Mottronic device based on a ${\mathrm{V}}_{2}{\mathrm{O}}_{3}$ epitaxial thin film. The experiments are supported by both finite-element simulations of the thermal problem and a simpler lumped-element model. The thermal models are benchmarked against results obtained at very low applied voltage ($\mathrm{\ensuremath{\Delta}}V=5$ mV). When the voltage is significantly increased ($\mathrm{\ensuremath{\Delta}}V=0.5$ V), but still in the linear below-switching-threshold region, our results show that the light excitation drives a volatile resistivity drop, which goes beyond the combined effect of laser and Joule heating. Our results impact on the development of protocols for the nonthermal control of the resistive-switching transition in correlated materials.