2022/01/19 by Xiaobo Ma, Guangwei Wang, Huican Mao +6
Chemistry · Materials Science · Mathematics · Physics and Astronomy · #2D Materials and Applications #Chemistry #Combinatorics #Condensed matter physics #Crystal structure #Crystallography #Graphene research and applications #Mathematics #Molecule #Monoclinic crystal system #Orthorhombic crystal system #Physics #Quantum mechanics #Topological Materials and Phenomena #Topological insulator #Topology (electrical circuits) #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.105.035138
28 pages, 11 figures
arxiv created 2022/01/19 · openalex publication_date 2022/01/24 · openalex created_date 2022/01/26 · arxiv updated 2022/02/02 · openalex updated_date 2026/08/05
The electronic structures and topological properties of the orthorhombic and monoclinic phases of the quasi-one-dimensional excitonic insulator Ta2NiSe5 are investigated based on density functional theory. In contrast to a single parity or band inversion across the Fermi level in many topological insulators studied previously, there are multiple parity and band inversions with or without spin-orbit coupling in both phases of Ta2NiSe5, resulting in more complex and topologically nontrivial electronic structures. The Dirac cone type surface states of the low-temperature monoclinic phase are also obtained. In this paper, we demonstrate that Ta2NiSe5 is a promising candidate as a three-dimensional topological excitonic insulator.