Isoniemi, T. orcid.org/0000-0003-0238-1006, Bouteyre, P., Hu, X. et al. (5 more authors) (2024) Realization of Z2 topological photonic insulators made from multilayer transition metal dichalcogenides. ACS Nano, 18 (47). ISSN 1936-0851
Abstract
Monolayers of semiconducting transition metal dichalcogenides (TMDs) have long attracted interest for their intriguing optical and electronic properties. Recently, TMDs in their quasi-bulk form have started to show considerable promise for nanophotonics thanks to their high refractive indices, large optical anisotropy, wide transparency windows reaching to the visible, and robust room temperature excitons promising for nonlinear optics. Adherence of TMD layers to any substrate via van der Waals forces is a further key enabler for the nanofabrication of complex photonic structures requiring heterointegration. Here, we use the attractive properties of TMDs and realize topological spin-Hall photonic lattices made of arrays of triangular nanoholes in 50 to 100 nm thick WS2 flakes exfoliated on SiO2/Si substrates. High-quality structures are achieved by taking advantage of anisotropic dry etching dictated by the crystal axes of WS2. Reflectance measurements at room temperature show a photonic gap opening in the near-infrared in trivial and topological phases. Unidirectional propagation along the domain interface is demonstrated in real space via circularly polarized laser excitation in samples with both zigzag and armchair domain boundaries. Finite-difference time-domain simulations are used to interpret optical spectroscopy results. Our work demonstrates the feasibility of more complex nanophotonic devices based on the layered (van der Waals) materials platform.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2024 The Authors. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
Keywords: | 2D materials; FDTD; metasurfaces; photonic crystals; topology; tungsten disulfide |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > School of Mathematical and Physical Sciences |
Funding Information: | Funder Grant number ENGINEERING AND PHYSICAL SCIENCE RESEARCH COUNCIL EP/S030751/1 ENGINEERING AND PHYSICAL SCIENCE RESEARCH COUNCIL EP/V007696/1 ENGINEERING AND PHYSICAL SCIENCE RESEARCH COUNCIL EP/V006975/1 ENGINEERING AND PHYSICAL SCIENCE RESEARCH COUNCIL EP/V047663/1 ENGINEERING AND PHYSICAL SCIENCE RESEARCH COUNCIL EP/V026496/1 |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 11 Dec 2024 16:07 |
Last Modified: | 11 Dec 2024 16:07 |
Published Version: | http://dx.doi.org/10.1021/acsnano.4c09295 |
Status: | Published |
Publisher: | American Chemical Society (ACS) |
Refereed: | Yes |
Identification Number: | 10.1021/acsnano.4c09295 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:220327 |