2018/02/10 by Motohiko Ezawa · 1 citation
Materials Science · Mathematics · Physics and Astronomy · #Advanced Condensed Matter Physics #Band gap #Business #Combinatorics #Condensed matter physics #Graphene research and applications #Mathematics #Order (exchange) #Physics #Semimetal #Topological Materials and Phenomena #Topological insulator #Topology (electrical circuits) #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.97.155305
published as Phys. Rev. B 97, 155305 (2018) · 4 pages, 7 figures
arxiv created 2018/02/10 · openalex publication_date 2018/04/17 · arxiv updated 2018/04/25 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We propose magnetic second-order topological insulators (SOTIs). First, we study a three-dimensional model. It is pointed out that the previously proposed topological hinge insulator has actually surface states along the [001] direction in addition to hinge states. We gap out these surface states by introducing magnetization, obtaining a SOTI only with hinge states. The bulk topological number is the Z2 index protected by the combined symmetry of the fourfold rotation and the inversion symmetry. We next study two-dimensional magnetic SOTIs, where the corner states are robust also in the presence of the magnetization. Finally, we construct a magnetic second-order topological semimetal by layering the two-dimensional magnetic SOTIs, where hinge-arc states are robust also in the presence of the magnetization.