Multiscale Modelling of Resistive Switching in Gold Nanogranular Films*

Metallic nanogranular films display a complex dynamical response to a constant bias, typically showing up as a resistive switching mechanism which, in turn, could be used to create electrical components for neuromorphic applications. To model such a phenomenon we use a multiscale computational approach blending together (i) an ab initio treatment of the electric current at the nanoscale, (ii) a molecular dynamics approach dictating structural rearrangements, and (iii) a finite-element solution of the heat equation for heat propagation in the sample. We also consider structural changes due to electromigration which are modelled on the basis of experimental observations on similar systems. Within such an approach, we manage to describe some distinctive features of the resistive switching occurring in a nanogranular film and provide a physical interpretation at the microscopic level.