Perpendicular Magnetization Switching Driven by Spin‐Orbit Torque for Artificial Synapses in Epitaxial Pt‐Based Multilayers

Abstract Perpendicular magnetization switching driven by spin‐orbit torque (SOT) exhibits nonvolatility and adjustability, which has great potential applications in magnetic random‐access memory neuromorphic computing. In this work, the SOT efficiency Pt (001)/NiFe (Py) (111)/Py bilayers is first investigated, where single crystal films polycrystalline Py are grown molecular beam epitaxy magnetron sputtering, respectively. The (001)‐oriented sample shows a larger than that of (111)‐oriented one, mainly attributed to facet‐dependent intrinsic spin Hall effect layer related Berry curvature electrical band structure. Then, epitaxial (001)‐based perpendicularly magnetized multilayers designed study perpendicular SOT. A continuous stable reversal successfully achieved, providing conceivable candidate for reliable variable imitation artificial synapses. magneto–optical Kerr imaging proves sustainable change state originates from multiple site domain nucleation growth ferromagnetic layer. This work provides an efficient method enhance efficiency, as well employs thin synaptic devices