Skyrmion-based racetrack multilevel data storage device manipulated by pinning

Magnetic skyrmions are particle-like topological protected spin structures that can be driven by electric current. We demonstrate a single skyrmion-based multilevel data storage device that could also work as the potential artificial synapse for neuromorphic computing. Four pinning sites are designed to situate the skyrmion in selective regions, whose resistances rise owing to the anisotropic magnetoresistance (AMR) induced by the skyrmion. Skyrmion’s position could denote the data levels when the device works as a multilevel data storage device. Pinning sites’ positions represent the synaptic weights when it functions as the artificial synapse. Multilevel data storage device’s data level change or the synapse’s potentiation and depression is realized by the electric current applied parallel to the track. Our work shows that the AMR could help to detect a single skyrmion without the magnetic tunnel junction. Moreover, the skyrmion manipulated by pinning provides an approach for precise control and helps realize skyrmion-based in-memory computing.