Higher-Order Synchronization, Bursting, and Tunable Phase Dynamics in Capacitively Coupled V ₃ O ₅ Relaxation Oscillators

Threshold switching and negative differential resistance in V 3 O 5 are assisted by a thermally induced insulator–metal transition that occurs at 420 K and provide the basis for fabricating a scalable relaxation oscillator. This study presents a detailed investigation of the dynamics of two capacitively coupled V 3 O 5 oscillators, showcasing their potential for neuromorphic computing and nonlinear signal processing. The coupled oscillators exhibit rich synchronization dynamics, broadly falling within three distinct synchronization regimes: (i) no coupling, where oscillators operated independently; (ii) weak coupling, featuring phase-tuning and higher-order synchronization; and (iii) strong coupling, associated with out-of-phase and burst synchronization. Phase-tuning in the weak coupling regime enables precise control of phase differences, supporting phase-based information encoding, while burst synchronization, emerging under strong coupling with a slow oscillator and a fast oscillator, enhances information transmission efficiency, mirroring biological spiking patterns. These dynamics are shown to be accurately reproduced by an LTspice model that includes thermally driven conduction in the V 3 O 5 -based threshold-switching device. These results establish V 3 O 5 as a viable platform for developing scalable, tunable, and energy-efficient neuromorphic architectures and bioinspired signal processing systems.