Higher-order topology in honeycomb lattice with Y-Kekulé distortions

Abstract

We investigate higher-order topological states in honeycomb lattice with Y-Kekulé distortions that preserve $C_{6v}$ crystalline symmetry. The gapped states in expanded and shrunken distortions are adiabatically connected to isolated hexamers and Y-shaped tetramer states, respectively, where the former possesses nontrivial higher-order topology characterized by a ${\mathbb{Z}}_6$ invariant. Topological corner states exist in a flake structure with expanded distortion where the hexamers are broken at the corners. Our work reveals that honeycomb lattice with Y-Kekulé distortions serves as a promising platform to study higher-order topological states.

5 pages, 3 figures

References in corpus (6)

• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• Quantum Spin Hall Insulator State in HgTe Quantum Wells
• Topological Crystalline Insulators
• Scheme to Achieve Silicon Topological Photonics
• $(d-2)$-dimensional edge states of rotation symmetry protected topological states
• Berry bands and pseudo-spin of topological photonic phases

Cited by in corpus (3)

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• Periodic Behavior of Topology in Graphene with Nanohole Array