Impurity-induced triple point fermions in twisted bilayer graphene
Autor(a) principal: | |
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Data de Publicação: | 2019 |
Outros Autores: | |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UNESP |
Texto Completo: | http://dx.doi.org/10.1103/PhysRevB.99.245118 http://hdl.handle.net/11449/228699 |
Resumo: | Triple point fermions are elusive electronic excitations that generalize Dirac and Weyl modes beyond the conventional high-energy paradigm. Yet, finding real materials naturally hosting these excitations at the Fermi energy has remained challenging. Here we show that twisted bilayer graphene is a versatile platform to realize robust triple point fermions in two dimensions. In particular, we establish that the introduction of localized impurities lifts one of the two degenerate Dirac cones, yielding triple point fermions at charge neutrality. Furthermore, we show that the valley polarization is preserved for certain impurity locations in the Moiré supercell for both weak and strong impurity potentials. We finally show that in the presence of interactions, a symmetry-broken state with local magnetization can develop out of the triple point bands, which can be selectively controlled by electrostatic gating. Our results put forward twisted bilayer graphene as a simple solid-state platform to realize triple point fermions at charge neutrality and demonstrate the nontrivial role of impurities in Moiré systems. |
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Impurity-induced triple point fermions in twisted bilayer grapheneTriple point fermions are elusive electronic excitations that generalize Dirac and Weyl modes beyond the conventional high-energy paradigm. Yet, finding real materials naturally hosting these excitations at the Fermi energy has remained challenging. Here we show that twisted bilayer graphene is a versatile platform to realize robust triple point fermions in two dimensions. In particular, we establish that the introduction of localized impurities lifts one of the two degenerate Dirac cones, yielding triple point fermions at charge neutrality. Furthermore, we show that the valley polarization is preserved for certain impurity locations in the Moiré supercell for both weak and strong impurity potentials. We finally show that in the presence of interactions, a symmetry-broken state with local magnetization can develop out of the triple point bands, which can be selectively controlled by electrostatic gating. Our results put forward twisted bilayer graphene as a simple solid-state platform to realize triple point fermions at charge neutrality and demonstrate the nontrivial role of impurities in Moiré systems.ICTP-SAIFR International Centre for Theoretical Physics South American Institute for Fundamental ResearchInstituto de Física Teórica Universidade Estadual PaulistaInstitute for Theoretical Physics ETH ZurichInstituto de Física Teórica Universidade Estadual PaulistaSouth American Institute for Fundamental ResearchUniversidade Estadual Paulista (UNESP)ETH ZurichRamires, Aline [UNESP]Lado, Jose L.2022-04-29T08:28:07Z2022-04-29T08:28:07Z2019-06-10info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articlehttp://dx.doi.org/10.1103/PhysRevB.99.245118Physical Review B, v. 99, n. 24, 2019.2469-99692469-9950http://hdl.handle.net/11449/22869910.1103/PhysRevB.99.2451182-s2.0-85068850920Scopusreponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengPhysical Review Binfo:eu-repo/semantics/openAccess2022-04-29T08:28:07Zoai:repositorio.unesp.br:11449/228699Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462024-05-23T11:02:10.802410Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false |
dc.title.none.fl_str_mv |
Impurity-induced triple point fermions in twisted bilayer graphene |
title |
Impurity-induced triple point fermions in twisted bilayer graphene |
spellingShingle |
Impurity-induced triple point fermions in twisted bilayer graphene Ramires, Aline [UNESP] |
title_short |
Impurity-induced triple point fermions in twisted bilayer graphene |
title_full |
Impurity-induced triple point fermions in twisted bilayer graphene |
title_fullStr |
Impurity-induced triple point fermions in twisted bilayer graphene |
title_full_unstemmed |
Impurity-induced triple point fermions in twisted bilayer graphene |
title_sort |
Impurity-induced triple point fermions in twisted bilayer graphene |
author |
Ramires, Aline [UNESP] |
author_facet |
Ramires, Aline [UNESP] Lado, Jose L. |
author_role |
author |
author2 |
Lado, Jose L. |
author2_role |
author |
dc.contributor.none.fl_str_mv |
South American Institute for Fundamental Research Universidade Estadual Paulista (UNESP) ETH Zurich |
dc.contributor.author.fl_str_mv |
Ramires, Aline [UNESP] Lado, Jose L. |
description |
Triple point fermions are elusive electronic excitations that generalize Dirac and Weyl modes beyond the conventional high-energy paradigm. Yet, finding real materials naturally hosting these excitations at the Fermi energy has remained challenging. Here we show that twisted bilayer graphene is a versatile platform to realize robust triple point fermions in two dimensions. In particular, we establish that the introduction of localized impurities lifts one of the two degenerate Dirac cones, yielding triple point fermions at charge neutrality. Furthermore, we show that the valley polarization is preserved for certain impurity locations in the Moiré supercell for both weak and strong impurity potentials. We finally show that in the presence of interactions, a symmetry-broken state with local magnetization can develop out of the triple point bands, which can be selectively controlled by electrostatic gating. Our results put forward twisted bilayer graphene as a simple solid-state platform to realize triple point fermions at charge neutrality and demonstrate the nontrivial role of impurities in Moiré systems. |
publishDate |
2019 |
dc.date.none.fl_str_mv |
2019-06-10 2022-04-29T08:28:07Z 2022-04-29T08:28:07Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://dx.doi.org/10.1103/PhysRevB.99.245118 Physical Review B, v. 99, n. 24, 2019. 2469-9969 2469-9950 http://hdl.handle.net/11449/228699 10.1103/PhysRevB.99.245118 2-s2.0-85068850920 |
url |
http://dx.doi.org/10.1103/PhysRevB.99.245118 http://hdl.handle.net/11449/228699 |
identifier_str_mv |
Physical Review B, v. 99, n. 24, 2019. 2469-9969 2469-9950 10.1103/PhysRevB.99.245118 2-s2.0-85068850920 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Physical Review B |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.source.none.fl_str_mv |
Scopus reponame:Repositório Institucional da UNESP instname:Universidade Estadual Paulista (UNESP) instacron:UNESP |
instname_str |
Universidade Estadual Paulista (UNESP) |
instacron_str |
UNESP |
institution |
UNESP |
reponame_str |
Repositório Institucional da UNESP |
collection |
Repositório Institucional da UNESP |
repository.name.fl_str_mv |
Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP) |
repository.mail.fl_str_mv |
|
_version_ |
1803045758994219008 |