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arXiv · 2207.01359

Recipe for higher-order topology on the triangular lattice

Philipp Eck·Yuan Fang·Domenico Di Sante·Giorgio Sangiovanni·Jennifer Cano
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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.

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Philipp Eck, Yuan Fang, Domenico Di Sante, Giorgio Sangiovanni, Jennifer Cano. 2022-07-04. Recipe for higher-order topology on the triangular lattice. https://doi.org/10.1103/physrevb.107.115130

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