  Since the experimental discovery of magnetic skyrmions achieved one decade
ago, there have been significant efforts to bring the virtual particles into
all-electrical fully functional devices, inspired by their fascinating physical
and topological properties suitable for future low-power electronics. Here, we
experimentally demonstrate such a device: electrically-operating skyrmion-based
artificial synaptic device designed for neuromorphic computing. We present that
controlled current-induced creation, motion, detection and deletion of
skyrmions in ferrimagnetic multilayers can be harnessed in a single device at
room temperature to imitate the behaviors of biological synapses. Using
simulations, we demonstrate that such skyrmion-based synapses could be used to
perform neuromorphic pattern-recognition computing using handwritten
recognition data set, reaching to the accuracy of ~89 percents, comparable to
the software-based training accuracy of ~94 percents. Chip-level simulation
then highlights the potential of skyrmion synapse compared to existing
technologies. Our findings experimentally illustrate the basic concepts of
skyrmion-based fully functional electronic devices while providing a new
building block in the emerging field of spintronics-based bio-inspired
computing.
