Electric‐Current‐Assisted Nucleation of Zero‐Field Hopfion Rings

X Xiaowen Chen (School of Laboratory Medicine and Biotechnology, Southern Medical University) D Dongsheng Song F Filipp N. Rybakov N Nikolai S. Kiselev L Long Li W Wen Shi (Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University) R Rui Wu (Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China.) X Xuewen Fu O Olle Eriksson S Stefan Blügel R Rafal E. Dunin‐Borkowski (Ernst Ruska‐Centre for Microscopy and Spectroscopy with Electrons Forschungszentrum Jülich Jülich Germany) H Haifeng Du F Fengshan Zheng (Spin‐X Institute School of Physics and Optoelectronics State Key Laboratory of Luminescent Materials and Devices Guangdong‐Hong Kong‐Macao Joint Laboratory of Optoelectronic and Magnetic Functional Materials South China University of Technology Guangzhou China)

Abstract

ABSTRACT Magnetic hopfions are 3D 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.

Article Details

Volume / Issue Vol. 38, Issue 21
Published April 01, 2026
ISSN 0935-9648
Publisher Unknown Publisher

Journal Info

Advanced Materials

Unknown Publisher

ISSN: 0935-9648 Physical Sciences

Authors (13)

X

Xiaowen Chen

School of Laboratory Medicine and Biotechnology, Southern Medical University

D

Dongsheng Song

F

Filipp N. Rybakov

N

Nikolai S. Kiselev

L

Long Li

W

Wen Shi

Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University

R

Rui Wu

Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China.

X

Xuewen Fu

O

Olle Eriksson

S

Stefan Blügel

R

Rafal E. Dunin‐Borkowski

Ernst Ruska‐Centre for Microscopy and Spectroscopy with Electrons Forschungszentrum Jülich Jülich Germany

H

Haifeng Du

F

Fengshan Zheng

Spin‐X Institute School of Physics and Optoelectronics State Key Laboratory of Luminescent Materials and Devices Guangdong‐Hong Kong‐Macao Joint Laboratory of Optoelectronic and Magnetic Functional Materials South China University of Technology Guangzhou China