Disorder-driven stochastic dynamics in Mott resistive-switching systems

Abstract

Controlled disorder in correlated materials provides a new route to emergent stochastic dynamics in neuromorphic hardware. Here we show that focused ion beam irradiation in VO$_{2}$- and V$_{2}$O$_{3}$-based resistive-switching oscillators induces a transition from regular periodic oscillations to strongly irregular stochastic firing, while simultaneously reducing the required switching energy by orders of magnitude. Under an applied electric field, these materials undergo a volatile insulator-to-metal transition characterized by the formation of percolating metallic filaments within an insulating bulk. Using numerical simulations based on the Mott resistor network, we demonstrate that defect-induced modifications to filament nucleation and stability drive these devices into stochastic oscillatory regimes. These results are validated by experimental measurements on irradiated VO$_{2}$ and V$_{2}$O$_{3}$ devices.