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arXiv · 2410.18016

Family of third-order topological insulators from Su-Schrieffer-Heeger stacking

Xun-Jiang Luo·Jia-Zheng Li·Meng Xiao·Fengcheng Wu
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Abstract

We construct a family of chiral symmetry-protected third-order topological insulators by stacking Su-Schrieffer-Heeger (SSH) chains and provide a unified topological characterization by a series of Bott indices. Our approach is informed by the analytical solution of corner states for the model Hamiltonians written as a summation of the extended SSH model along three orthogonal directions. By utilizing the generalized Pauli matrices, an enumeration of the constructed model Hamiltonians generates ten distinct models, including the well-studied three-dimensional Benalcazar-Bernevig-Hughes model. By performing a boundary projection analysis for the ten models, we find that certain surfaces and hinges of the systems can exhibit, respectively, nontrivial second-order and first-order topology in the phase of the third-order topological insulators. Furthermore, we analyze the phase diagram for one of the predicted models and reveal a rich set of topological phases, including the third-order topological insulators, second-order weak topological insulators, and second-order nodal semimetals.

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Xun-Jiang Luo, Jia-Zheng Li, Meng Xiao, Fengcheng Wu. 2024-10-23. Family of third-order topological insulators from Su-Schrieffer-Heeger stacking. https://doi.org/10.1103/physrevb.111.035115

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