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arXiv · 2103.15667

Three-dimensional higher-order topological insulator protected by cubic symmetry

Valerii I. Kachin·Maxim A. Gorlach
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Abstract

Recently discovered photonic higher-order topological insulators enable unprecedented flexibility in the robust localization of light in structures of different dimensionality. While the potential of the two-dimensional systems is currently under active investigation, only a few studies explore the physics of the three-dimensional higher-order topological insulators. Here we propose a three-dimensional structure with cubic symmetry exhibiting vanishing bulk polarization but nonzero corner charge and hosting a zero-dimensional corner state mediated by the long-range interactions. We trace the evolution of the corner state with the next-nearest-neighbor coupling strength and prove the topological origin of the corner mode calculating the associated topological invariants. Our results thus reveal the potential of long-range couplings for the formation of three-dimensional higher-order topological phases.

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Valerii I. Kachin, Maxim A. Gorlach. 2021-03-29. Three-dimensional higher-order topological insulator protected by cubic symmetry. https://doi.org/10.1103/physrevapplied.16.024032

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