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Critical point for Bose–Einstein condensation of excitons in graphite
An exciton is an electron–hole pair bound by attractive Coulomb interaction. Short-lived excitons have been detected by a variety of experimental probes in numerous contexts. An excitonic insulator, a collective state of such excitons, has been more elusive. Here, thanks to Nernst measurements in pu...
Autores principales: | , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
National Academy of Sciences
2020
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7720211/ https://www.ncbi.nlm.nih.gov/pubmed/33199600 http://dx.doi.org/10.1073/pnas.2012811117 |
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author | Wang, Jinhua Nie, Pan Li, Xiaokang Zuo, Huakun Fauqué, Benoît Zhu, Zengwei Behnia, Kamran |
author_facet | Wang, Jinhua Nie, Pan Li, Xiaokang Zuo, Huakun Fauqué, Benoît Zhu, Zengwei Behnia, Kamran |
author_sort | Wang, Jinhua |
collection | PubMed |
description | An exciton is an electron–hole pair bound by attractive Coulomb interaction. Short-lived excitons have been detected by a variety of experimental probes in numerous contexts. An excitonic insulator, a collective state of such excitons, has been more elusive. Here, thanks to Nernst measurements in pulsed magnetic fields, we show that in graphite there is a critical temperature ([Formula: see text] = 9.2 K) and a critical magnetic field ([Formula: see text] = 47 T) for Bose–Einstein condensation of excitons. At this critical field, hole and electron Landau subbands simultaneously cross the Fermi level and allow exciton formation. By quantifying the effective mass and the spatial separation of the excitons in the basal plane, we show that the degeneracy temperature of the excitonic fluid corresponds to this critical temperature. This identification would explain why the field-induced transition observed in graphite is not a universal feature of three-dimensional electron systems pushed beyond the quantum limit. |
format | Online Article Text |
id | pubmed-7720211 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | National Academy of Sciences |
record_format | MEDLINE/PubMed |
spelling | pubmed-77202112020-12-18 Critical point for Bose–Einstein condensation of excitons in graphite Wang, Jinhua Nie, Pan Li, Xiaokang Zuo, Huakun Fauqué, Benoît Zhu, Zengwei Behnia, Kamran Proc Natl Acad Sci U S A Physical Sciences An exciton is an electron–hole pair bound by attractive Coulomb interaction. Short-lived excitons have been detected by a variety of experimental probes in numerous contexts. An excitonic insulator, a collective state of such excitons, has been more elusive. Here, thanks to Nernst measurements in pulsed magnetic fields, we show that in graphite there is a critical temperature ([Formula: see text] = 9.2 K) and a critical magnetic field ([Formula: see text] = 47 T) for Bose–Einstein condensation of excitons. At this critical field, hole and electron Landau subbands simultaneously cross the Fermi level and allow exciton formation. By quantifying the effective mass and the spatial separation of the excitons in the basal plane, we show that the degeneracy temperature of the excitonic fluid corresponds to this critical temperature. This identification would explain why the field-induced transition observed in graphite is not a universal feature of three-dimensional electron systems pushed beyond the quantum limit. National Academy of Sciences 2020-12-01 2020-11-16 /pmc/articles/PMC7720211/ /pubmed/33199600 http://dx.doi.org/10.1073/pnas.2012811117 Text en Copyright © 2020 the Author(s). Published by PNAS. https://creativecommons.org/licenses/by-nc-nd/4.0/ https://creativecommons.org/licenses/by-nc-nd/4.0/This open access article is distributed under Creative Commons Attribution-NonCommercial-NoDerivatives License 4.0 (CC BY-NC-ND) (https://creativecommons.org/licenses/by-nc-nd/4.0/) . |
spellingShingle | Physical Sciences Wang, Jinhua Nie, Pan Li, Xiaokang Zuo, Huakun Fauqué, Benoît Zhu, Zengwei Behnia, Kamran Critical point for Bose–Einstein condensation of excitons in graphite |
title | Critical point for Bose–Einstein condensation of excitons in graphite |
title_full | Critical point for Bose–Einstein condensation of excitons in graphite |
title_fullStr | Critical point for Bose–Einstein condensation of excitons in graphite |
title_full_unstemmed | Critical point for Bose–Einstein condensation of excitons in graphite |
title_short | Critical point for Bose–Einstein condensation of excitons in graphite |
title_sort | critical point for bose–einstein condensation of excitons in graphite |
topic | Physical Sciences |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7720211/ https://www.ncbi.nlm.nih.gov/pubmed/33199600 http://dx.doi.org/10.1073/pnas.2012811117 |
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