Field effect transistor like behaviour of Skyrmions in Nanowire Memory Devices

Abstract Skyrmions, as topologically stable spin textures, exhibit favorable characteristics for information transmission. However, in nanoscale devices, the skyrmion Hall effect (SkHE) may hinder their rectilinear propagation. This work represents the integration of magnetic anisotropy gradients with geometric notch structures, systematically revealing their synergistic regulatory mechanism on the nonreciprocal transport behavior of skyrmions. The results reveal that, in the absence of notches, skyrmion motion is strongly governed by the direction of the anisotropy gradient. In contrast, when both notches and electric currents are introduced, the interplay between the anisotropy gradient and notch depth has a pronounced impact on the unidirectional behavior of skyrmions in the nanotrack. It proposes a method for controlling the unidirectional motion of skyrmions based on gradient-notch co-design, providing a novel strategy and theoretical foundation for the development of low-power, highly reliable nanoscale spintronic field effect transistor.Furthermore, we extend this investigation to skyrmion bags with different multi-skyrmion states. While less stable, they demonstrate significantly higher gating sensitivity, offering a trade-off between Operational Margin and switching efficiency for advanced spintronic logic applications.