Comprehensive Search for Topological Materials using Symmetry Indicators

March 21, 2019

Fig. 1 (Tang, et al.*)

Over the past decade, topological materials—in which the topology of electron bands in the bulk material leads to robust, unconventional surface states and electromagnetism—have attracted much attention. Although several theoretically proposed topological materials have been experimentally confirmed, extensive experimental exploration of topological properties, as well as applications in realistic devices, has been restricted by the lack of topological materials in which interference from trivial Fermi surface states is minimized. An international team of researchers, including Prof. Ashvin Vishwanath, applied their own method of symmetry indicators to all suitable nonmagnetic compounds in all 230 possible space groups. A database search revealed thousands of candidate topological materials, of which the ersearchers highlighted 241 topological insulators and 142 topological crystalline insulators that have either noticeable full bandgaps or a considerable direct gap together with small trivial Fermi pockets. Furthermore, they listed 692 topological semimetals that have band crossing points located near the Fermi level. These candidate materials open up the possibility of using topological materials in next-generation electronic devices. This research is described in a recent article in Nature:

*Feng Tang, Hoi Chun Po, Ashvin Vishwanath & Xiangang Wan, "Comprehensive search for topological materials using symmetry indicators," Nature 566 (2019)