Скачать или смотреть Jiadong Zhang, "Topological Spin Textures in Two-dimensions and Beyond," 9/28/23

Abstract: Chiral magnets are a series of magnets with broken inversion symmetry. A new type of spin interaction therein, the Dzyaloshinskii-Moriya interaction, stimulates the formation of many novel topological spin textures. One important example is the emergence of magnetic skyrmion, whose nontrivial topology enables unique dynamical property and thermal stability and gives rise to promising applications in future spintronic devices. In the first part of the talk, I will discuss the formation and dynamics of skyrmions and skyrmionic textures. I will also discuss the topological Hall effect, a key transport signature of the skyrmion, and how it could show up in other non-skyrmionic materials. In the second part of the talk, I will generalize the skyrmion texture from two dimensions (2D) to three dimensions (3D), and discuss skyrmionic 3D spin textures in chiral magnets, including target skyrmion, skyrmion bundle, and skyrmionic vortices. I will also discuss the magnetic hopfion, a rigorously defined 3D topological texture. We propose the presence of zero-field hopfion in synthetic chiral magnetic multilayers. All these 3D textures exhibit novel dynamical properties that can be formulated in terms of collective coordinates. These works could stimulate the development of 3D spintronics.