Physics Special Colloquium: Three-dimensional topological spin textures in chiral magnets

Prof. Jiadong Zang, Department of Physics and Astronomy, University of New Hampshire

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. However, skyrmion is just a two-dimensional texture. Its three-dimensional (3D) counterparts are widely unexplored. In this talk, I will discuss realization of 3D skyrmionic textures, 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.

Bio: Jiadong Zang received bachelor degree in 2007 and PhD degree in 2012, both from Fudan University. He was a postdoctoral fellow in the Institute of Quantum Matter at the Johns Hopkins University during 2012-2015. In 2015, he joined both the Department of Physics and Materials Science Program at the University of New Hampshire as an assistant professor, and was promoted to the associate professor in 2020. He is currently the director of Materials Science Program at UNH. His research focuses on many aspects of magnetism, especially topological magnetism, quantum transport, functional magnetic materials and 3D tomography. His research has been continuously supported by Department of Energy. He is recipient of 2020 IUPAP Young Scientist Medal in the field of magnetism, and an Alexander von Humboldt Fellow for Experienced Researchers.