Electric-current-assisted nucleation of zero-field hopfion rings
Abstract
Magnetic hopfions are three-dimensional topological solitons -- knotted, vortex-like spin configurations. In chiral magnets, hopfions can appear as isolated structures or they can be linked to skyrmion strings. Previous studies employed a sophisticated protocol and a special sample geometry to nucleate such hopfions linked to one or a few skyrmion strings. Here, we introduce an electric-current-assisted nucleation protocol that is simple and independent of the sample shape and size. The resulting hopfions exhibit extraordinary stability in the presence of both positive and negative magnetic fields, in perfect agreement with micromagnetic simulations. We also present a comprehensive framework for classifying hopfions, skyrmions, and merons by deriving the corresponding homotopy group.
Keywords
Cite
@article{arxiv.2601.17790,
title = {Electric-current-assisted nucleation of zero-field hopfion rings},
author = {Xiaowen Chen and Dongsheng Song and Filipp N. Rybakov and Nikolai S. Kiselev and Long Li and Wen Shi and Rui Wu and Xuewen Fu and Olle Eriksson and Stefan Bluegel and Haifeng Du and Fengshan Zheng},
journal= {arXiv preprint arXiv:2601.17790},
year = {2026}
}