Atomistic theory of the moiré Hofstadter butterfly in magic-angle graphene

DOI	Trouver le DOI : https://doi.org/10.1103/PhysRevB.109.075166
Auteur	Rechercher : Wania Rodrigues, Alina¹Identifiant ORCID : https://orcid.org/0009-0008-3064-3476; Rechercher : Bieniek, Maciej^{2, 3}Identifiant ORCID : https://orcid.org/0000-0003-4505-1998; Rechercher : Potasz, Paweł⁴Identifiant ORCID : https://orcid.org/0000-0001-8383-2205; Rechercher : Miravet, Daniel¹Identifiant ORCID : https://orcid.org/0000-0002-2908-4645; Rechercher : Thomale, Ronny²; Rechercher : Korkusiński, Marek^{5, 1}Identifiant ORCID : https://orcid.org/0000-0002-2238-336X; Rechercher : Hawrylak, Paweł¹Identifiant ORCID : https://orcid.org/0000-0002-4651-3536
Affiliation	Université d'Ottawa Universität Würzburg Wroclaw University of Science and Technology Nicolaus Copernicus University Conseil national de recherches Canada. Quantique et nanotechnologies
Bailleur de fonds	Rechercher : Natural Sciences and Engineering Research Council of Canada; Rechercher : Deutsche Forschungsgemeinschaft; Rechercher : Narodowe Centrum Nauki
Format	Texte, Article
Sujet	edge states; flat bands; Landau levels; local density of states; topological insulators; strongly correlated systems; topological materials; twisted bilayer graphene; tight-binding model
Résumé	We present here a Hofstadter's butterfly spectrum for the magic-angle twisted bilayer graphene obtained using an ab initio-based multimillion-atom tight-binding model. We incorporate a hexagonal boron nitride substrate and out-of-plane atomic relaxation. The effects of a magnetic field are introduced via the Peierls modification of the long-range tight-binding matrix elements and the Zeeman spin splitting effects. A nanoribbon geometry is studied, and the quantum size effects for the sample widths up to 1 µm are analyzed both for a large energy window and for the flat band around the Fermi level. For sufficiently wide ribbons, where the role of the finite geometry is minimized, we obtain and plot the Hofstadter spectrum and identify the in-gap Chern numbers by counting the total number of chiral edge states crossing these gaps. Subsequently, we examine the Wannier diagrams to identify the insulating states at charge neutrality. We establish the presence of three types of electronic states: moiré, mixed, and conventional. These states describe both the bulk Landau levels and the edge states crossing gaps in the spectrum. The evolution of the bulk moiré flat band wave functions in the magnetic field is investigated, predicting a decay of the electronic density from the moiré centers as the magnetic flux increases. Furthermore, the spatial properties of the three types of edge states are studied, illustrating the evolution of their localization as a function of the nanoribbon momentum.
Date de publication	2024-02-27
Maison d’édition	American Physical Society
Dans	Physical Review B 109, nº 7, 075166 (27 février 2024).
Langue	anglais
Publications évaluées par des pairs	Oui
Exporter la notice	Exporter en format RIS
Signaler une correction	Signaler une correction (s'ouvre dans un nouvel onglet)
Identificateur de l’enregistrement	39dca9f9-61ed-4ac4-8978-c28643a9467a
Enregistrement créé	2026-01-23
Enregistrement modifié	2026-02-24

Détails de la page

Par :

Conseil national de recherches Canada

Date de modification :: 2026-07-10