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

Threshold switching and negative differential resistance in V3O5 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 V3O5 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 V3O5-based threshold-switching device. These results establish V3O5 as a viable platform for developing scalable, tunable, and energy-efficient neuromorphic architectures and bioinspired signal processing systems.