Asymmetric Motion of Magnetic Skyrmions in Ferromagnetic Nanotubes Induced by a Magnetic Field

Abstract

Magnetic skyrmions, featuring topological stability and low driving current density, are believed to be a promising candidate of information carriers. One of the obstacles to application is the skyrmion Hall effect, which can lead to the annihilation of moving skyrmions at the lateral boundary of thin-film tracks. In order to resolve this issue, it was recently proposed to exploit ferromagnetic nanotubes as alternative skyrmion guides. In this work, we investigate the field-effect of current-driven skyrmion motion in nanotubes using micromagnetic simulations. It is found that, in the presence of an axial field, the skyrmion motion becomes asymmetric in tubes. This is fundamentally different from the flat strip, in which a field has little influence on the skyrmion dynamics. Based on the dissipation tensor determined by the spin texture of the skyrmions, the solution of the Thiele equation is obtained, yielding a perfect match with simulations. We argue that the asymmetry of the skyrmion dynamics originates from the curvature of the nanotube.

Dynamic susceptibility of Fe3O4 nanotubes

“…Among these, one of the most intensely investigated are magnetic nanotubes, because they exhibit a high aspect ratio, like nanowires, but with two functionalizable surfaces [ 7 ], in addition to offering a lightweight alternative to design mechanical nanodevices with minimal loss of mechanical performance [ 8 ]. Furthermore, these tubes allow the mobility of domain walls [ 9 ] and skyrmionic structures [ 10 , 11 ], making them promising candidates as information carriers.…”

Static and Dynamic Magnetic Properties of Fe3O4 Nanotubes

“…Moreover, Yan et al [ 4 ] have demonstrated that domain walls in a tubular geometry are more durable than those in flat strips, which can even suppress the Walker breakdown in these nanostructures. Bao et al [ 5 ] proposed using ferromagnetic nanotubes as alternative skyrmion guides, which are a promising candidate for information carriers, while Yang et al [ 6 ] investigated the stability of skyrmion formation in magnetic nanotubes. Additionally, Rojas-Nunez et al [ 7 ] has shown that magnetic nanotubes provide a lightweight alternative for designing mechanical nanodevices with minimal loss of mechanical performance.…”