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.

Bimeron clusters in chiral antiferromagnets

A magnetic bimeron is an in-plane topological counterpart of a magnetic skyrmion.Despite the topological equivalence,their statics and dynamics could be distinct,making them attractive from the perspectives of both physics and spintronic applications.In this work,we demonstrate the stabilization of bimeron solitons and clusters in the antiferromagnetic(AFM)thin film with interfacial Dzyaloshinskii–Moriya interaction(DMI).Bimerons demonstrate high current-driven mobility as generic AFM solitons,while featuring anisotropic and relativistic dynamics excited by currents with in-plane and out-ofplane polarizations,respectively.Moreover,these spin textures can absorb other bimeron solitons or clusters along the translational direction to acquire a wide range of Néel topological numbers.The clustering involves the rearrangement of topological structures,and gives rise to remarkable changes in static and dynamical properties.The merits of AFM bimeron clusters reveal a potential path to unify multibit data creation,transmission,storage,and even topology-based computation within the same material system,and may stimulate spintronic devices enabling innovative paradigms of data manipulations.