Electrical Manipulation of Field‐Free Magnetization Switching Driven by Spin‐Orbit Torque in Amorphous Gradient‐Mn 3 Sn

Abstract Switching the magnetization without an assisted magnetic field is crucial for the application of spin‐orbit torque (SOT) devices. However, the realization of field‐free magnetization switching usually calls for intricate design and growth of heterostructure. In this study, it is found that the amorphous Mn 3 Sn can generate a highly efficient spin current with a strong z ‐direction polarization component due to its spontaneous composition gradient, which switches the perpendicular magnetization in the absence of an external field. The SOT efficiency of gradient‐Mn 3 Sn can be reversibly modulated by the ionic liquid gating based on the migration of hydrogen ions, which reverses the polarity of field‐free magnetization switching and allows the realization of 16 binary Boolean logic functions in a single device by pure electrical methods. These results not only offer a very convenient route to field‐free magnetization switching but also can promote the development of in‐memory computing for spintronic devices.