Magnetic topological semimetals (TSMs) have been the source of many new discoveries. With the intrinsic interplay between magnetic order and electronic properties, magnetic TSMs allow for an effective control of the topological electronic states by tuning the spin configuration, and therefore are promising materials for next-generation electronic and spintronic applications. While many TSMs are theoretically predicted, the number of experimentally identified magnetic ones is rather limited. In this talk, I will introduce my recent efforts on the design and synthesis of two types of magnetic TSMs: one featuring nearly idealized Dirac electronic states, and the other highlighting the Weyl nodal ring states in the vicinity of the Fermi level. In both cases, I will go through the design strategy, and the detailed experimental verification. Remarkably, both magnetic TSM systems show prominent magneto-transport properties that are rarely seen in other magnetic TSMs. In this talk, the role of CDWs in stabilizing complex magnetism (possibly skyrmions) is also discussed. 

Dr. Shiming Lei is currently a research scientist in the Department of Physics and Astronomy at Rice University. He obtained his PhD degree in Materials Science and Engineering at the Pennsylvania State University in December 2017. His PhD work is mainly on the exploration of microstructure-property relationship on a class of materials that have no inversion-symmetry, including ferroelectric materials, multiferroics and magnetic noncentrosymmetric metals. After that, he did his postdoc research at Princeton University for three years, and expanded his research scope to materials synthesis and design, mainly focusing on the materials with emergent and tunable electronic or magnetic properties, including magnetic topological semimetals, skyrmion hosting materials and van der Waals crystals.

To request for meeting link, please write to phweb@ust.hk.