Recipe for higher-order topology on the triangular lattice

Abstract

We present a recipe for an electronic 2D higher order topological insulator (HOTI) on the triangular lattice that can be realized in a large family of materials. The essential ingredient is mirror symmetry breaking, which allows for a finite quadrupole moment and trivial ${\mathbb{Z}}_2$ index. The competition between spin-orbit coupling and the symmetry breaking terms gives rise to four topologically distinct phases; the HOTI phase appears when symmetry breaking dominates, including in the absence of spin-orbit coupling. We identify triangular monolayer adsorbate systems on the (111) surface of zincblende/diamond type substrates as ideal material platforms and predict the HOTI phase for $X=$(Al,B,Ga) on SiC.

5 pages, 4 figures and 1 table. Supplementary material: 5 pages, 3 figures and 10 tables

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Cited by in corpus (2)

• A mono-atomic orbital-based 1D topological crystalline insulator
• Orbital Hall effect and topology on a two-dimensional triangular lattice: from bulk to edge