R&D: Single-Bit Full Adder and Logic Gate Based on Synthetic Antiferromagnetic Bilayer Skyrmions

Rare Metals has published an article written by Kai Yu Mak, School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, 518172, China, Jing Xia, College of Physics and Electronic Engineering, Sichuan Normal University, Chengdu, 610068, China, Xi-Chao Zhang, Department of Electrical and Computer Engineering, Shinshu University, Nagano, 380-8553, Japan, Li Li, School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, 518172, China, Mouad Fattouhi, Department of Applied Physics, University of Salamanca, Salamanca, 37008, Spain, Motohiko Ezawa, Department of Applied Physics, University of Tokyo, Tokyo, 113-8656, Japan, Xiao-Xi Liu, Department of Electrical and Computer Engineering, Shinshu University, Nagano, 380-8553, Japan, and Yan Zhou, School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, 518172, China.

Abstract: “Skyrmion-based devices are promising candidates for non-volatile memory and low-delay time computation. Many skyrmion-based devices execute operation by controlling skyrmion trajectory, which can be impeded by the skyrmion Hall effect. Here, the design of skyrmion-based arithmetic devices built on synthetic antiferromagnetic (SyAF) structures is presented, where the structure can greatly suppress skyrmion Hall effect. In this study, the operations of skyrmion-based half adder, full adder, and XOR logic gate are executed by introducing geometric notches and tilted edges, which can annihilate or diverge skyrmion. Performance of these skyrmion-based devices is evaluated, where the delay time and energy-delay product of the single-bit full adder are 1.95 ns and 2.50 × 10⁻²² Js, which are only 12% and 79% those of the previously proposed skyrmion-based single-bit full adder. This improvement is significant in the construction of ripple-carry adder and ripple-carry adder-subtractor. Therefore, our skyrmion-based SyAF arithmetic device is a promising candidate to develop high-speed spintronic devices.“