Niitsu Kodai, Liu Yizhou, Booth Alexander C, Yu Xiuzhen, Mathur Nitish, Stolt Matthew J, Shindo Daisuke, Jin Song, Zang Jiadong, Nagaosa Naoto, Tokura Yoshinori
RIKEN Center for Emergent Matter Science (CEMS), Wako, Japan.
Department of Materials Science and Engineering, Kyoto University, Kyoto, Japan.
Nat Mater. 2022 Mar;21(3):305-310. doi: 10.1038/s41563-021-01186-x. Epub 2022 Jan 27.
The concept of topology has dramatically expanded the research landscape of magnetism, leading to the discovery of numerous magnetic textures with intriguing topological properties. A magnetic skyrmion is an emergent topological magnetic texture with a string-like structure in three dimensions and a disk-like structure in one and two dimensions. Skyrmions in zero dimensions have remained elusive due to challenges from many competing orders. Here, by combining electron holography and micromagnetic simulations, we uncover the real-space magnetic configurations of a skyrmionic vortex structure confined in a B20-type FeGe tetrahedral nanoparticle. An isolated skyrmionic vortex forms at the ground state and this texture shows excellent robustness against temperature without applying a magnetic field. Our findings shed light on zero-dimensional geometrical confinement as a route to engineer and manipulate individual skyrmionic metastructures.
拓扑学概念极大地拓展了磁学的研究领域，促使人们发现了众多具有迷人拓扑性质的磁结构。磁斯格明子是一种新兴的拓扑磁结构，在三维空间中呈线状结构，在一维和二维空间中呈盘状结构。由于受到多种竞争序的挑战，零维斯格明子一直难以捉摸。在此，我们通过结合电子全息术和微磁模拟，揭示了限制在B20型FeGe四面体纳米颗粒中的斯格明子涡旋结构的实空间磁构型。在基态形成了一个孤立的斯格明子涡旋，并且这种结构在不施加磁场的情况下表现出对温度的出色鲁棒性。我们的发现为通过零维几何限制来设计和操纵单个斯格明子亚结构提供了思路。
