2018/05/18 by Feng Tang, Hoi Chun Po, Ashvin Vishwanath +1 · 1 citation
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Band gap #Degenerate energy levels #Dirac (video compression format) #Geometry #Graphene research and applications #Homogeneous space #Physics #Quantum mechanics #Semimetal #Surface (topology) #Surface states #Topological Materials and Phenomena #Topological insulator #Topology (electrical circuits) #cond-mat.mes-hall #cond-mat.mtrl-sci
paper · pdf · doi:10.1038/s41567-019-0418-7
published as Nature Physics 15, 470 (2019)
arxiv created 2018/05/18 · openalex publication_date 2019/02/11 · arxiv updated 2019/05/14 · openalex created_date 2020/11/23 · openalex updated_date 2026/08/05
Although the richness of spatial symmetries has led to a rapidly expanding inventory of possible topological crystalline (TC) phases of electrons, physical realizations have been slow to materialize due to the practical difficulty to ascertaining band topology in realistic calculations. Here, we integrate the recently established theory of symmetry indicators of band topology into first-principle band-structure calculations, and test it on a databases of previously synthesized crystals. The combined algorithm is found to efficiently unearth topological materials and predict topological properties like protected surface states. On applying our algorithm to just 8 out of the 230 space groups, we already discover numerous materials candidates displaying a diversity of topological phenomena, which are simultaneously captured in a single sweep. The list includes recently proposed classes of TC insulators that had no previous materials realization as well as other topological phases, including: (i) a screw-protected 3D TC insulator, \beta-MoTe2, with gapped surfaces except for 1D helical "hinge" states; (ii) a rotation-protected TC insulator BiBr with coexisting surface Dirac cones and hinge states; (iii) non-centrosymmetric Z2 topological insulators undetectable using the well-established parity criterion, AgXO (X=Na,K,Rb); (iv) a Dirac semimetal MgBi2O6; (v) a Dirac nodal-line semimetal AgF2; and (vi) a metal with three-fold degenerate band crossing near the Fermi energy, AuLiMgSn. Our work showcases how the recent theoretical insights on the fundamentals of band structures can aid in the practical goal of discovering new topological materials.