Band Engineering of Dirac Semimetals Using Charge Density Waves. Issue 30 (17th June 2021)

• Record Type: Journal Article
• Authors: Lei, Shiming; Teicher, Samuel M. L.; Topp, Andreas; Cai, Kehan; Lin, Jingjing; Cheng, Guangming; Salters, Tyger H.; Rodolakis, Fanny; McChesney, Jessica L.; Lapidus, Saul; Yao, Nan; Krivenkov, Maxim; Marchenko, Dmitry; Varykhalov, Andrei; Ast, Christian R.; Car, Roberto; Cano, Jennifer; Vergniory, Maia G.; Ong, N. Phuan; Schoop, Leslie M.
• Is Part Of: Advanced materials. Volume 33:Issue 30(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-06-17
• Subjects: charge density waves -- Dirac semimetals -- nonsymmorphic symmetry; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.202101591
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: New developments in the field of topological matter are often driven by materials discovery, including novel topological insulators, Dirac semimetals, and Weyl semimetals. In the last few years, large efforts have been made to classify all known inorganic materials with respect to their topology. Unfortunately, a large number of topological materials suffer from non‐ideal band structures. For example, topological bands are frequently convoluted with trivial ones, and band structure features of interest can appear far below the Fermi level. This leaves just a handful of materials that are intensively studied. Finding strategies to design new topological materials is a solution. Here, a new mechanism is introduced, which is based on charge density waves and non‐symmorphic symmetry, to design an idealized Dirac semimetal. It is then shown experimentally that the antiferromagnetic compound GdSb0.46 Te1.48 is a nearly ideal Dirac semimetal based on the proposed mechanism, meaning that most interfering bands at the Fermi level are suppressed. Its highly unusual transport behavior points to a thus far unknown regime, in which Dirac carriers with Fermi energy very close to the node seem to gradually localize in the presence of lattice and magnetic disorder. Abstract : A charge density wave (CDW) is proposed as a tool to engineer an idealized Dirac semimetal. The CDW gaps all bands at the Fermi level except the Dirac cone, which is protected by non‐symmorphic symmetry. Antiferromagnetic compounds of GdSb x Te2− x −δ are designed and synthesized to test this proposed mechanism. Unusual transport behavior is discovered and points to a new regime.