Topological electronic states in holey graphyne

Fuente: arXiv
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Main Authors: Jiang, Yong-Cheng, Kariyado, Toshikaze, Hu, Xiao
Format: Preprint
Published: 2023
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author Jiang, Yong-Cheng
Kariyado, Toshikaze
Hu, Xiao
author_facet Jiang, Yong-Cheng
Kariyado, Toshikaze
Hu, Xiao
contents We unveil that the holey graphyne (HGY), a two-dimensional carbon allotrope where benzene rings are connected by two $-$C$\equiv$C$-$ bonds fabricated recently in a bottom-up way, exhibits topological electronic states. Using first-principles calculations and Wannier tight-binding modeling, we discover a higher-order topological invariant associated with $C_2$ symmetry of the material, and show that the resultant corner modes appear in nanoflakes matching to the structure of precursor reported previously, which are ready for direct experimental observations. In addition, we find that a band inversion between emergent $g$-like and $h$-like orbitals gives rise to a nontrivial topology characterized by $\mathbb{Z}_2$ invariant protected by an energy gap as large as 0.52 eV, manifesting helical edge states mimicking those in the prominent quantum spin Hall effect, which can be accessed experimentally after hydrogenation in HGY. We hope these findings trigger interests towards exploring the topological electronic states in HGY and related future electronics applications.
format Preprint
id arxiv_https___arxiv_org_abs_2310_14625
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Topological electronic states in holey graphyne
Jiang, Yong-Cheng
Kariyado, Toshikaze
Hu, Xiao
Mesoscale and Nanoscale Physics
Materials Science
We unveil that the holey graphyne (HGY), a two-dimensional carbon allotrope where benzene rings are connected by two $-$C$\equiv$C$-$ bonds fabricated recently in a bottom-up way, exhibits topological electronic states. Using first-principles calculations and Wannier tight-binding modeling, we discover a higher-order topological invariant associated with $C_2$ symmetry of the material, and show that the resultant corner modes appear in nanoflakes matching to the structure of precursor reported previously, which are ready for direct experimental observations. In addition, we find that a band inversion between emergent $g$-like and $h$-like orbitals gives rise to a nontrivial topology characterized by $\mathbb{Z}_2$ invariant protected by an energy gap as large as 0.52 eV, manifesting helical edge states mimicking those in the prominent quantum spin Hall effect, which can be accessed experimentally after hydrogenation in HGY. We hope these findings trigger interests towards exploring the topological electronic states in HGY and related future electronics applications.
title Topological electronic states in holey graphyne
topic Mesoscale and Nanoscale Physics
Materials Science
url https://arxiv.org/abs/2310.14625