Experimental Robust Spontaneous Synchronizations in Coupled NbO <i> <sub>x</sub> </i> Oscillation Neurons for Unconventional Computing
Hyun Wook Kim, Seung‐Youl Kang, Jaehyun Moon, Nayeon Kim, Eunryeong Hong, Seyeong Jeon, Seonuk Jeon, Jiyong Woo
Abstract
In this brief, we demonstrate experimentally achieved oscillation dynamics in coupled NbOx threshold switch (TS)-based oscillation neurons (ONs). We first show the challenges in observing oscillation caused by device variability, which is further validated through HSPICE simulations. To obtain robust oscillation response, a reliable TS developed via atomic layer deposition for conformal NbOx is introduced. By developing coupled NbOx ONs using a coupling resistor ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${R}_{C}$ </tex-math></inline-formula> ), the out-of-phase synchronization is demonstrated owing to the weak connection. Moreover, we achieve a transition to in-phase synchronization as the coupling strength increases, showing an inverse relationship with the magnitude of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${R}_{C}$ </tex-math></inline-formula> . Based on these results, oscillatory neural networks, where multiple NbOx ONs are fully connected, are examined to execute pattern recognition via MATALB simulations.