腾讯会议 ID：941-958-814 会议密码：1022

主持人：张颖 研究员

联系人：傅琦 (fuqi@iphy.ac.cn)

Abstract：
Magnetic hopfions are three-dimensional topological solitons, objects with particle-like properties, making them particularly intriguing for fundamental research and potential applications in spintronics. In this talk, I begin with theoretical investigations of hopfions in frustrated magnets, which provide insight into their stability and possible mechanisms for manipulation. I will then describe how subsequent studies of three-dimensional magnetic textures—including skyrmion braids, dipole strings, skyrmion bags, and hopfion rings—advanced our understanding of complex spin configurations and established the experimental approaches needed to explore them. These developments paved the way for the observation of isolated magnetic hopfions in chiral magnets and, more recently, their stabilization at and above room temperature in Co₈Zn₈Mn₄. Micromagnetic simulations and topological analysis further reveal how fusing bimeron–antibimeron pairs can form three dimensional hopfions. Finally, I will discuss these findings in the broader context of three-dimensional topological magnetism, highlighting the remaining challenges in the controlled creation, manipulation, and direct observation of magnetic hopfions.

[1] F. Zheng et al., Nature 623, 718 (2023).
[2] X. Chen et al., Nat. Phys. 22, 736 (2026). 
[3] K.Zhu et al., arXiv:2607.26839 (2026).

Brief CV of Prof. Nikolai S. Kiselev：
Dr. Nikolai S. Kiselev is a staff scientist at the Peter Grünberg Institute, Forschungszentrum Jülich, Germany. He received his Ph.D. in Physics from the Technical University of Dresden in 2010. His research focuses on theoretical and computational magnetism, particularly two- and three dimensional topological magnetic textures, including skyrmions, merons, hopfions, and chiral bobbers.