Orbital shift-induced boundary obstructed topological materials with a large energy gap

Abstract

We propose boundary obstructed topological phases caused by Wannier orbital shift between ordinary atomic sites, which, however, cannot be indicated by symmetry eigenvalues at high symmetry momenta (symmetry indicators) in bulk. On the open boundary, Wannier charge centers can shift to different atoms from those in bulk, leading to in-gap surface states, higher-order hinge states or corner states. To demonstrate such orbital-shift-induced boundary obstructed topological insulators, we predict eight material candidates, all of which were overlooked in present topological databases. Metallic surface states, hinge states, or corner states cover the large bulk energy gap (for example, more than 1 eV in TlGaTe${}_2$) at related boundary, which are ready for experimental detection. Additionally, we find these materials are also fragile topological insulators with hourglass like surface states.

References in corpus (7)

• Electric Multipole Moments, Topological Multipole Moment Pumping, and Chiral Hinge States in Crystalline Insulators
• Higher-order Topology of Axion Insulator EuIn${}_2$As${}_2$
• Maximally Localized Wannier Functions within the FLAPW formalism
• Edge-Corner Correspondence: Boundary-Obstructed Topological Phases with Chiral Symmetry
• Three-Dimensional Real Space Invariants, Obstructed Atomic Insulators and A New Principle for Active Catalytic Sites
• Filling-Enforced Obstructed Atomic Insulators
• Orbital shift-induced boundary obstructed topological materials with a large energy gap

Cited by in corpus (1)

• Orbital shift-induced boundary obstructed topological materials with a large energy gap