Skyrmion-based logic gates controlled by electric currents in synthetic antiferromagnet

Abstract

Skyrmions in synthetic antiferromagnetic (SAF) systems have attracted much attention in recent years due to their superior stability, high-speed mobility and completely compensated skyrmion Hall effect. They are promising building blocks for the next generation of magnetic storage and computing devices with ultra-low energy and ultra-high density. Here, we theoretically investigate the motion of a skyrmion in a SAF bilayer racetrack and find the velocity of a skyrmion can be controlled jointly by the edge effect and the driving force induced by the spin current. Furthermore, we propose a logic gate that can realize different logic functions of logic AND, OR, NOT, NAND, NOR and XOR gates. Several effects including the spin-orbit torque, the skyrmion Hall effect, skyrmion-skyrmion repulsion and skyrmion-edge interaction are considered in this design. Our work may provide a way to utilize the SAF skyrmion as a versatile information carrier for future energy-efficient logic gates.

Reconfigurable Skyrmion-Based Logic Gates: Versatile Design and Full-Scale Implementation

“…demonstrated that VCMA can efficiently control the Néel vector in antiferromagnets with perpendicular anisotropy, enabling coherent excitation and manipulation of AFM order. The first-principles calculations further support these findings, with identified VCMA behavior in ultrathin FeRh/MgO bilayers and in materials like L1 0 -MnPd and MgO-capped MnPt AFM films. − Therefore, the precise manipulation of the electric field emerges as a promising avenue for realizing a reconfigurable logic gate within AFM materials, offering flexibility in performing different logic functions. , Additionally, an essential aspect of skyrmion-based logic gates lies in the interaction between skyrmions themselves in AFM thin films, particularly the sky–sky topological repulsion, highlighting their tunability and potential for logic operations. − Moreover, thoughtful geometric designs are one of the key mechanisms in reconfigurable skyrmion logic gates (RSL) as they grant the ability to exert control over the motion, interaction, and stability of skyrmions, all of which are critical elements for achieving the desired logic operations. , …”

Stability analysis of magnetization in a perpendicular magnetic layer driven by spin Hall effect

“…[35] It is reported that magnetic skyrmions is a topology protected magnetic structure, which can be used as a low energy consumption and efficient information storage device. [36][37][38]…”