Single-bit full adder and logic gate based on synthetic antiferromagnetic bilayer skyrmions

Skyrmion-based devices are promising candi-dates for non-volatile memory and low-delay time com-putation.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 antiferromag-netic(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.