  Magnetic skyrmions are particle-like topological spin configurations, which
can carry binary information and thus are promising building blocks for future
spintronic devices. In this work, we investigate the relationship between the
skyrmion dynamics and the characteristics of injected current in a
skyrmion-based spin torque nano-oscillator, where the excitation source is
introduced from a point nano-contact at the center of the nanodisk. It is found
that the skyrmion will move away from the center of the nanodisk if it is
driven by a spin-polarized current; however, it will return to the initial
position in the absence of stimulus. Therefore, we propose a skyrmion-based
artificial spiking neuron, which can effectively implement the
leaky-integrate-fire operation. We study the feasibility of the skyrmion-based
spiking neuron by using micromagnetic simulations. Our results may provide
useful guidelines for building future magnetic neural networks with ultra-high
density and ultra-low energy consumption.
