Integration of external electric fields in molecular dynamics simulation models for resistive switching devices

Abstract

Resistive switching devices emerged a huge amount of interest as promising candidates for non-volatile memories as well as artificial synapses due to their memristive behavior. The main physical and chemical phenomena which define their functionality are driven by externally applied voltages and the resulting electric fields. Although molecular dynamics simulations are widely used in order to describe the dynamics on the corresponding atomic length and time scales, there is a lack of models which allow for the actual driving force of the dynamics, i.e., externally applied electric fields. This is due to the restriction of currently applied models to solely conductive, non-reactive, or insulating materials, with thicknesses on the order of the potential cutoff radius, i.e., 10 Å. In this work, we propose a generic model, which can be applied in particular to describe the resistive switching phenomena of metal-insulator-metal systems. It has been shown that the calculated electric field and force distribution in case of the chosen example system Cu/a-SiO2/Cu are in agreement with the fundamental field theoretical expectations.