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Observation of room temperature excitons in an atomically thin topological insulator
Optical spectroscopy of ultimately thin materials has significantly enhanced our understanding of collective excitations in low-dimensional semiconductors. This is particularly reflected by the rich physics of excitons in atomically thin crystals which uniquely arises from the interplay of strong Co...
Autores principales: | , , , , , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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Nature Publishing Group UK
2022
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9588767/ https://www.ncbi.nlm.nih.gov/pubmed/36274087 http://dx.doi.org/10.1038/s41467-022-33822-8 |
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author | Syperek, Marcin Stühler, Raul Consiglio, Armando Holewa, Paweł Wyborski, Paweł Dusanowski, Łukasz Reis, Felix Höfling, Sven Thomale, Ronny Hanke, Werner Claessen, Ralph Di Sante, Domenico Schneider, Christian |
author_facet | Syperek, Marcin Stühler, Raul Consiglio, Armando Holewa, Paweł Wyborski, Paweł Dusanowski, Łukasz Reis, Felix Höfling, Sven Thomale, Ronny Hanke, Werner Claessen, Ralph Di Sante, Domenico Schneider, Christian |
author_sort | Syperek, Marcin |
collection | PubMed |
description | Optical spectroscopy of ultimately thin materials has significantly enhanced our understanding of collective excitations in low-dimensional semiconductors. This is particularly reflected by the rich physics of excitons in atomically thin crystals which uniquely arises from the interplay of strong Coulomb correlation, spin-orbit coupling (SOC), and lattice geometry. Here we extend the field by reporting the observation of room temperature excitons in a material of non-trivial global topology. We study the fundamental optical excitation spectrum of a single layer of bismuth atoms epitaxially grown on a SiC substrate (hereafter bismuthene or Bi/SiC) which has been established as a large-gap, two-dimensional (2D) quantum spin Hall (QSH) insulator. Strongly developed optical resonances are observed to emerge around the direct gap at the K and K’ points of the Brillouin zone, indicating the formation of bound excitons with considerable oscillator strength. These experimental findings are corroborated, concerning both the character of the excitonic resonances as well as their energy scale, by ab-initio GW and Bethe-Salpeter equation calculations, confirming strong Coulomb interaction effects in these optical excitations. Our observations provide evidence of excitons in a 2D QSH insulator at room temperature, with excitonic and topological physics deriving from the very same electronic structure. |
format | Online Article Text |
id | pubmed-9588767 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2022 |
publisher | Nature Publishing Group UK |
record_format | MEDLINE/PubMed |
spelling | pubmed-95887672022-10-25 Observation of room temperature excitons in an atomically thin topological insulator Syperek, Marcin Stühler, Raul Consiglio, Armando Holewa, Paweł Wyborski, Paweł Dusanowski, Łukasz Reis, Felix Höfling, Sven Thomale, Ronny Hanke, Werner Claessen, Ralph Di Sante, Domenico Schneider, Christian Nat Commun Article Optical spectroscopy of ultimately thin materials has significantly enhanced our understanding of collective excitations in low-dimensional semiconductors. This is particularly reflected by the rich physics of excitons in atomically thin crystals which uniquely arises from the interplay of strong Coulomb correlation, spin-orbit coupling (SOC), and lattice geometry. Here we extend the field by reporting the observation of room temperature excitons in a material of non-trivial global topology. We study the fundamental optical excitation spectrum of a single layer of bismuth atoms epitaxially grown on a SiC substrate (hereafter bismuthene or Bi/SiC) which has been established as a large-gap, two-dimensional (2D) quantum spin Hall (QSH) insulator. Strongly developed optical resonances are observed to emerge around the direct gap at the K and K’ points of the Brillouin zone, indicating the formation of bound excitons with considerable oscillator strength. These experimental findings are corroborated, concerning both the character of the excitonic resonances as well as their energy scale, by ab-initio GW and Bethe-Salpeter equation calculations, confirming strong Coulomb interaction effects in these optical excitations. Our observations provide evidence of excitons in a 2D QSH insulator at room temperature, with excitonic and topological physics deriving from the very same electronic structure. Nature Publishing Group UK 2022-10-23 /pmc/articles/PMC9588767/ /pubmed/36274087 http://dx.doi.org/10.1038/s41467-022-33822-8 Text en © The Author(s) 2022 https://creativecommons.org/licenses/by/4.0/Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) . |
spellingShingle | Article Syperek, Marcin Stühler, Raul Consiglio, Armando Holewa, Paweł Wyborski, Paweł Dusanowski, Łukasz Reis, Felix Höfling, Sven Thomale, Ronny Hanke, Werner Claessen, Ralph Di Sante, Domenico Schneider, Christian Observation of room temperature excitons in an atomically thin topological insulator |
title | Observation of room temperature excitons in an atomically thin topological insulator |
title_full | Observation of room temperature excitons in an atomically thin topological insulator |
title_fullStr | Observation of room temperature excitons in an atomically thin topological insulator |
title_full_unstemmed | Observation of room temperature excitons in an atomically thin topological insulator |
title_short | Observation of room temperature excitons in an atomically thin topological insulator |
title_sort | observation of room temperature excitons in an atomically thin topological insulator |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9588767/ https://www.ncbi.nlm.nih.gov/pubmed/36274087 http://dx.doi.org/10.1038/s41467-022-33822-8 |
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