Schematic illustration of strain-mediated magnetization precessional switching and a domain wall injection mechanism in a nano-magnet with in-plane shape anisotropy.

Voltage-controlled magnetic skyrmions have attracted special attention because they satisfy the requirements for well-controlled high-efficiency and energy saving for future skyrmion-based neuron device applications. In this work, we propose a compact leaky-integrate-fire (LIF) spiking neuron device by using the voltage-driven skyrmion dynamics in a multiferroic nanodisk structure. The skyrmion dynamics is controlled by well tailoring voltage-induced piezostrains, where the skyrmion radius can be effectively modulated by applying the piezostrain pulses. Like the biological neuron, the proposed skyrmionic neuron will accumulate a membrane potential as skyrmion radius is varied by inputting the continuous piezostrain spikes, and the skyrmion radius will return to the initial state in the absence of piezostrain. Therefore, this skyrmion radius-based membrane potential will reach a definite threshold value by the strain stimuli and then reset by removing the stimuli. Such the LIF neuronal functionality and the behaviors of the proposed skyrmionic neuron device are elucidated through the micromagnetic simulation studies. Our results may benefit the utilization of skyrmionic neuron for constructing the future energy-efficient and voltage-tunable spiking neural networks.

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