Zero-to-Perfect Toron Hall Effect in Chiral Magnets

Topological spin textures can be efficiently driven by an electric current, and hence they can serve as the information careers in novel spintronics devices. Thus far, current-induced drift motions have been mainly studied for the skyrmions in a two-dimensional magnet. Meanwhile, their practical application is hindered by the drift motion of skyrmions transverse to the current, called the skyrmion Hall effect. Here, we theoretically investigate current-driven dynamics of three-dimensional topological spin textures called magnetic torons, composed of layered skyrmions with two singularities called Bloch points at their ends, in metallic chiral magnets [1]. Through numerical simulations based on the Landau-Lifshitz-Gilbert equation, we show that the torons also exhibit a Hall motion, but surprisingly over a wide range of the Hall angle spanning from the zero Hall effect, a purely longitudinal motion, to the perfect Hall effect, a purely transverse motion accompanied by no longitudinal motion. Furthermore, we reveal that these flexible and controllable behaviors stem from anisotropic potential barriers on the discrete lattice, which can be particularly relevant for nanoscale torons recently discovered in MnSi_1-xGe_x. This study makes an important step to understanding the current-induced dynamics of the three-dimensional topological spin textures and would shed light on their applications to novel spintronic devices.

[1] K. Shimizu et al., arXiv:2407.02983 (2024).