Modeling defect engineering in Mott neuromorphic devices

Mott materials have recently emerged as promising candidates for the hardware implementation of neuromorphic circuitry. When under an applied electric field, these materials undergo a volatile insulator-to-metal phase transition characterized by the formation of percolating metallic filaments within their insulating bulk. Through the introduction of controlled disorder by means of focused ion beam irradiation, defect engineering in Mott materials can both control the location and shape of these filaments and greatly reduce the switching power required for filament formation. By using numerical simulations based on the Mott resistor network, we demonstrate that these material defects can drive Mott spiking neuron circuits into highly stochastic regimes as seen experimentally in irradiated devices, and also require orders of magnitude less energy to initiate their neuronal spiking behavior.