2024 journal article
Search for an antiferromagnetic Weyl semimetal in (MnTe)<sub> <i>m</i> </sub>(Sb<sub>2</sub>Te<sub>3</sub>)<sub> <i>n</i> </sub> and (MnTe)<sub> <i>m</i> </sub>(Bi<sub>2</sub>Te<sub>3</sub>)<sub> <i>n</i> </sub> superlattices
JOURNAL OF PHYSICS-CONDENSED MATTER, 36(40).
author keywords: Weyl semimetal; topological phase transition; antiferromagnet; magnetic topological materials; spintronics
open access via doi.org (publisher)
Source: Web Of Science
Added: July 22, 2024
Abstract The interaction between topology and magnetism can lead to novel topological materials including Chern insulators, axion insulators, and Dirac and Weyl semimetals. In this work, a family of van der Waals layered materials using MnTe and Sb 2 Te 3 or Bi 2 Te 3 superlattices as building blocks are systematically examined in a search for antiferromagnetic Weyl semimetals, preferably with a simple node structure. The approach is based on controlling the strength of the exchange interaction as a function of layer composition to induce the phase transition between the topological and the normal insulators. Our calculations, utilizing a combination of first-principles density functional theory and tight-binding analyses based on maximally localized Wannier functions, clearly indicate a promising candidate for a type-I magnetic Weyl semimetal. This centrosymmetric material, Mn 10 Sb 8 Te 22 (or (MnTe) m (Sb 2 Te 3 ) n with m = 10 and n = 4), shows ferromagnetic intralayer and antiferromagnetic interlayer interactions in the antiferromagnetic ground state. The obtained electronic bandstructure also exhibits a single pair of Weyl points in the spin-split bands consistent with a Weyl semimetal. The presence of Weyl nodes is further verified with Berry curvature, Wannier charge center, and surface state (i.e. Fermi arc) calculations. Other combinations of the MnSbTe-family materials are found to be antiferromagnetic topological or normal insulators on either side of the Mn:Sb ratio, respectively, illustrating the topological phase transition as anticipated. A similar investigation in the homologous (MnTe) m (Bi 2 Te 3 ) n system produces mostly nontrivial antiferromagnetic insulators due to the strong spin–orbit coupling. When realized, the antiferromagnetic Weyl semimetals in the simplest form (i.e. a single pair of Weyl nodes) are expected to provide a promising candidate for low-power spintronic applications.