Magnetic hopfion, a three-Dimensional Topological Spin Textures

Unlike conventional collinear magnetic orders such as ferromagnetism and antiferromagnetism, non-collinear spin orderings in magnetic materials give rise to topological configurations such as domain walls, vortices, skyrmions, etc. Owing to their topological nature, these textures exhibit extra stability and novel spin dynamics, which give out promises of their applications in racetrack memory, magnetic tunneling junction, and neuromorphic computing. However, these textures exist in low dimensions. It would be interesting to generalize them into three dimensions. In this talk, I will introduce a three-dimensional topological spin texture called the magnetic hopfion. Besides theoretical framework, its experimental observation and dynamics will be presented. Challenges including 3D magnetic reconstruction, magnetic simulations, and materials realization will be addressed.