Development of Property-Performance Links for Vanadium Dioxide Nonlinear Dynamical Memristors via Local Activity Modeling*

The absence of properties-performance relations is a crucial limitation for translating the surging interest in nonlinear electronic devices into their large-scale commercial deployment in neuromorphic networks. In order to develop systematic reverse- and forward-design principles for neuromorphic materials, materials and device engineers need a unified framework, within which “exotic” dynamical behaviors (negative differential resistance, persistent spiking oscillations, spontaneous localization of current channels) are linked with nonlinear transport physics. In this work, we advance the dynamical theory of Local Activity as such a unified framework for modeling neuromorphic behavior and extracting nonlinear materials properties in VO2/SiN electro-thermal memristors. Using a recent physical recontextualization of Local Activity in terms of competition between Joule Heating and Newtonian Cooling thermal feedback, we develop systematic least-squares fitting procedures to experimental steady-state and dynamical data to independently characterize the temperature-dependent electrical and thermal transport material properties of the VO2 memristors, and directly link the data to the underlying electro-thermal nonlinearities. Beyond accurately reproducing the experimental data, the modeling procedure is (1) predictive, in terms of producing surprising but independently-verifiable electro-thermal material characterization, and (2) informative, in terms of linking features of the steady state curve to both dynamical behavior and to the underlying nonlinear electro-thermal transport. This recontextualization of Local Activity compact modeling in terms of systematic fitting procedures has been a missing link in predictively connecting nonlinear electronic material properties to neuromorphic device performance, and should enable rapid screening of candidate materials manifesting nonlinear electrical and thermal transport physics.