Experimental Evaluation of Silicon Nitride Memristors as Coupling Elements for Chimera States in Chaotic Oscillator Networks

Abstract

Chimera states have attracted significant research interest due to their potential in modeling brain network functionality. Memristive nano-crossbars, known for their energy efficiency, massive parallelism, and synaptic-like properties, serve as a promising coupling medium in brain-inspired applications. The operation of these devices is strongly dictated by the non-linear mechanisms of memristor devices when studying synchronization phenomena. Expanding upon our previous work, which explored sneak-path currents in Chimera states, this study investigates the impact of fabricated Silicon Nitride (SiN) devices on the dynamics of Chua circuit (CC) networks. We conducted experimental evaluations to confirm the ability of SiN devices to retain their resistance state, thereby ensuring consistency in the crossbar array, a critical factor in maintaining chimera states during experiments. We employed an exponential memristor model to further investigate the non-linear dynamics within the CC network. Our results not only confirm the formation of various synchronization structures, such as chimera states and full chaotic synchronization but also reveal the intriguing formation of phase-lag structures. These structures, induced by the SiN-fitted model, exhibit distinctive characteristics marked by subtle and non-linear coupling behaviors, particularly evident at near-zero voltages. After analyzing our results, we present a comprehensive phase-parametric regime map, obtained by varying the coupling strength bifurcation parameter. This map provides valuable insights into the mechanisms governing the dynamics of CC networks equipepd with SiN-based memristor nanodevices, which have proven capable of capturing the complex dynamics of chimera states.