R&D: Spintronic Computational Memory Using Symmetry-Dependent Spin–Orbit Torque Switching

Journal of Physics D: Applied Physics has published an article written by Yinuo Shi, Kequn Chi, Zhou Li, Wenbiao Zhang, Xiang Feng, Yun Xing, Hao Meng, and Bo Liu, Key Laboratory of Spintronics Materials, Devices and Systems of Zhejiang Province, Hangzhou 311305, People’s Republic of China.

Abstract: “The non-volatile logic gates that can perform both storage and computing functions are the elementary components for in-memory computing. In this work, we propose a spin–orbit torque based non-volatile reconfigurable logic device. The spatial-dependent spin current generated by a Y-shaped heavy metal layer is utilized to break the symmetry of a perpendicular magnetic tunnel junction (MTJ) with Dzyaloshinskii–Moriya interaction, which leads to a symmetry-dependent magnetization switching. Both bipolar and unipolar magnetization switching can be achieved based on the proposed scheme. The feasibility of the prototype device is demonstrated through the micromagnetic simulations. Moreover, we assign these symmetry-dependent switching characteristics with different Boolean logic operations. Three logic gates including Majority, XOR, and AND/XOR are reconfigured. Furthermore, we offer a different approach to perform an N-bit full subtractor/adder function using a single MTJ. The proposed device paves the way toward a programmable and highly parallel logic-in-memory architecture in the near future.“