Prediction of strong topological insulator phase in kagome metal RV6Ge6

The kagome lattice (comprising geometrically frustrated corner-sharing triangles), historically used in basket weaving and religious rituals, has emerged as an exciting platform for studying exotic phases of matter in quantum physics, such as quantum spin liquids, Chern magnetism, chiral charge dens...

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Main Authors: Ahsan, Taosif, Hsu, Chia-Hsiu, Hossain, Md. Shafayat, Hasan, M. Zahid
Other Authors: School of Physical and Mathematical Sciences
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Language:English
Published: 2024
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Online Access:https://hdl.handle.net/10356/174016
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-1740162024-03-18T15:35:24Z Prediction of strong topological insulator phase in kagome metal RV6Ge6 Ahsan, Taosif Hsu, Chia-Hsiu Hossain, Md. Shafayat Hasan, M. Zahid School of Physical and Mathematical Sciences Physics Insulator phasis Kagome lattice The kagome lattice (comprising geometrically frustrated corner-sharing triangles), historically used in basket weaving and religious rituals, has emerged as an exciting platform for studying exotic phases of matter in quantum physics, such as quantum spin liquids, Chern magnetism, chiral charge density waves, and topological superconductivity. Despite the immense interest in kagome compounds, the exploration of strong topological insulators within this lattice has been scarce. In this work, we propose a new family of kagome compounds, RV6Ge6 (R = rare-earth atom), to host such a strong topological insulator phase. This phase is characterized by backscattering resilient surface states protected by the bulk insulating gap developed due to band inversions. The topological invariants of the band structure in Hilbert space allow us to identify different classes of gapped band structures and confirm the existence of a Z2 topological invariant for bands near the Fermi energy in RV6Ge6 through ab initio calculations. Our investigation establishes RV6Ge6 as a strong topological insulator family among kagome compounds, further expanding the topological possibilities in this exotic lattice geometry. Notably, the electronic structure near the Fermi energy is dominated by the vanadium kagome lattice plane, presenting an exciting opportunity to study kagome physics in isolation from trivial bands. Furthermore, the observation of the topological insulator phase in RV6Ge6, where the vanadium valence state is in the d orbital, creates an unprecedented opportunity to introduce long-range magnetic order within the topological state via doping in the vanadium site and introducing unpaired d-electrons. National Research Foundation (NRF) Published version Theoretical work at Princeton University was supported by the Gordon and 286 Betty Moore Foundation (Grant No. GBMF4547, M.Z.H.). Work at Nanyang Technological University was supported by the National Research Foundation, Singapore under its Fellowship Award (Award No. NRF-NRFF13-2021-0010). 2024-03-12T01:58:00Z 2024-03-12T01:58:00Z 2023 Journal Article Ahsan, T., Hsu, C., Hossain, M. S. & Hasan, M. Z. (2023). Prediction of strong topological insulator phase in kagome metal RV6Ge6. Physical Review Materials, 7(10), 104204-1-104204-6. https://dx.doi.org/10.1103/PhysRevMaterials.7.104204 2475-9953 https://hdl.handle.net/10356/174016 10.1103/PhysRevMaterials.7.104204 2-s2.0-85174842305 10 7 104204-1 104204-6 en NRF-NRFF13-2021-0010 Physical Review Materials © 2023 American Physical Society. All rights reserved. This article may be downloaded for personal use only. Any other use requires prior permission of the copyright holder. The Version of Record is available online at http://doi.org/10.1103/PhysRevMaterials.7.104204 application/pdf
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic Physics
Insulator phasis
Kagome lattice
spellingShingle Physics
Insulator phasis
Kagome lattice
Ahsan, Taosif
Hsu, Chia-Hsiu
Hossain, Md. Shafayat
Hasan, M. Zahid
Prediction of strong topological insulator phase in kagome metal RV6Ge6
description The kagome lattice (comprising geometrically frustrated corner-sharing triangles), historically used in basket weaving and religious rituals, has emerged as an exciting platform for studying exotic phases of matter in quantum physics, such as quantum spin liquids, Chern magnetism, chiral charge density waves, and topological superconductivity. Despite the immense interest in kagome compounds, the exploration of strong topological insulators within this lattice has been scarce. In this work, we propose a new family of kagome compounds, RV6Ge6 (R = rare-earth atom), to host such a strong topological insulator phase. This phase is characterized by backscattering resilient surface states protected by the bulk insulating gap developed due to band inversions. The topological invariants of the band structure in Hilbert space allow us to identify different classes of gapped band structures and confirm the existence of a Z2 topological invariant for bands near the Fermi energy in RV6Ge6 through ab initio calculations. Our investigation establishes RV6Ge6 as a strong topological insulator family among kagome compounds, further expanding the topological possibilities in this exotic lattice geometry. Notably, the electronic structure near the Fermi energy is dominated by the vanadium kagome lattice plane, presenting an exciting opportunity to study kagome physics in isolation from trivial bands. Furthermore, the observation of the topological insulator phase in RV6Ge6, where the vanadium valence state is in the d orbital, creates an unprecedented opportunity to introduce long-range magnetic order within the topological state via doping in the vanadium site and introducing unpaired d-electrons.
author2 School of Physical and Mathematical Sciences
author_facet School of Physical and Mathematical Sciences
Ahsan, Taosif
Hsu, Chia-Hsiu
Hossain, Md. Shafayat
Hasan, M. Zahid
format Article
author Ahsan, Taosif
Hsu, Chia-Hsiu
Hossain, Md. Shafayat
Hasan, M. Zahid
author_sort Ahsan, Taosif
title Prediction of strong topological insulator phase in kagome metal RV6Ge6
title_short Prediction of strong topological insulator phase in kagome metal RV6Ge6
title_full Prediction of strong topological insulator phase in kagome metal RV6Ge6
title_fullStr Prediction of strong topological insulator phase in kagome metal RV6Ge6
title_full_unstemmed Prediction of strong topological insulator phase in kagome metal RV6Ge6
title_sort prediction of strong topological insulator phase in kagome metal rv6ge6
publishDate 2024
url https://hdl.handle.net/10356/174016
_version_ 1794549316094787584