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Orbitally Controlled Quantum Hall States in Decoupled Two‐Bilayer Graphene Sheets
The authors report on integer and fractional quantum Hall states in a stack of two twisted Bernal bilayer graphene sheets. By exploiting the momentum mismatch in reciprocal space, the single‐particle tunneling between both bilayers is suppressed. Since the bilayers are spatially separated by only 0....
Autores principales: | , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
John Wiley and Sons Inc.
2023
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10427396/ https://www.ncbi.nlm.nih.gov/pubmed/37259684 http://dx.doi.org/10.1002/advs.202300574 |
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author | Kim, Soyun Kim, Dohun Watanabe, Kenji Taniguchi, Takashi Smet, Jurgen H. Kim, Youngwook |
author_facet | Kim, Soyun Kim, Dohun Watanabe, Kenji Taniguchi, Takashi Smet, Jurgen H. Kim, Youngwook |
author_sort | Kim, Soyun |
collection | PubMed |
description | The authors report on integer and fractional quantum Hall states in a stack of two twisted Bernal bilayer graphene sheets. By exploiting the momentum mismatch in reciprocal space, the single‐particle tunneling between both bilayers is suppressed. Since the bilayers are spatially separated by only 0.34 nm, the stack benefits from strong interlayer Coulombic interactions. These interactions can cause the formation of a Bose–Einstein condensate. Indeed, such a condensate is observed for half‐filling in each bilayer sheet. However, only when the partially filled levels have orbital index 1. It is absent for partially filled levels with orbital index 0. This discrepancy is tentatively attributed to the role of skyrmion/anti‐skyrmion pair excitations and the dependence of the energy of these excitations on the orbital index. The application of asymmetric top and bottom gate voltages enables to influence the orbital nature of the electronic states of the graphene bilayers at the chemical potential and to navigate in orbital mixed space. The latter hosts an even denominator fractional quantum Hall state at total filling of −3/2. These observations suggest a unique edge reconstruction involving both electrons and chiral p‐wave composite fermions. |
format | Online Article Text |
id | pubmed-10427396 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2023 |
publisher | John Wiley and Sons Inc. |
record_format | MEDLINE/PubMed |
spelling | pubmed-104273962023-08-17 Orbitally Controlled Quantum Hall States in Decoupled Two‐Bilayer Graphene Sheets Kim, Soyun Kim, Dohun Watanabe, Kenji Taniguchi, Takashi Smet, Jurgen H. Kim, Youngwook Adv Sci (Weinh) Research Articles The authors report on integer and fractional quantum Hall states in a stack of two twisted Bernal bilayer graphene sheets. By exploiting the momentum mismatch in reciprocal space, the single‐particle tunneling between both bilayers is suppressed. Since the bilayers are spatially separated by only 0.34 nm, the stack benefits from strong interlayer Coulombic interactions. These interactions can cause the formation of a Bose–Einstein condensate. Indeed, such a condensate is observed for half‐filling in each bilayer sheet. However, only when the partially filled levels have orbital index 1. It is absent for partially filled levels with orbital index 0. This discrepancy is tentatively attributed to the role of skyrmion/anti‐skyrmion pair excitations and the dependence of the energy of these excitations on the orbital index. The application of asymmetric top and bottom gate voltages enables to influence the orbital nature of the electronic states of the graphene bilayers at the chemical potential and to navigate in orbital mixed space. The latter hosts an even denominator fractional quantum Hall state at total filling of −3/2. These observations suggest a unique edge reconstruction involving both electrons and chiral p‐wave composite fermions. John Wiley and Sons Inc. 2023-05-31 /pmc/articles/PMC10427396/ /pubmed/37259684 http://dx.doi.org/10.1002/advs.202300574 Text en © 2023 The Authors. Advanced Science published by Wiley‐VCH GmbH https://creativecommons.org/licenses/by/4.0/This is an open access article under the terms of the http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Research Articles Kim, Soyun Kim, Dohun Watanabe, Kenji Taniguchi, Takashi Smet, Jurgen H. Kim, Youngwook Orbitally Controlled Quantum Hall States in Decoupled Two‐Bilayer Graphene Sheets |
title | Orbitally Controlled Quantum Hall States in Decoupled Two‐Bilayer Graphene Sheets |
title_full | Orbitally Controlled Quantum Hall States in Decoupled Two‐Bilayer Graphene Sheets |
title_fullStr | Orbitally Controlled Quantum Hall States in Decoupled Two‐Bilayer Graphene Sheets |
title_full_unstemmed | Orbitally Controlled Quantum Hall States in Decoupled Two‐Bilayer Graphene Sheets |
title_short | Orbitally Controlled Quantum Hall States in Decoupled Two‐Bilayer Graphene Sheets |
title_sort | orbitally controlled quantum hall states in decoupled two‐bilayer graphene sheets |
topic | Research Articles |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10427396/ https://www.ncbi.nlm.nih.gov/pubmed/37259684 http://dx.doi.org/10.1002/advs.202300574 |
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