Weak-coupling theory of magic-angle twisted bilayer graphene

Strong correlations occur in magic-angle twisted bilayer graphene (MATBG) when the octet of flat moiré minibands centered on charge neutrality (CN) is partially occupied. The octet consists of a single valence band and a single conduction band for each of four degenerate spin-valley flavors. Motivat...

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Detalles Bibliográficos
Autores: Zhu, Jihang, Torre, Iacopo|||0000-0001-6515-181X, Polini, Marco, MacDonald, Allan H.
Tipo de recurso: artículo
Fecha de publicación:2024
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/427275
Acceso en línea:https://hdl.handle.net/2117/427275
https://dx.doi.org/10.1103/PhysRevB.110.L121117
Access Level:acceso abierto
Palabra clave:Gravitational waves
Graphene
Energy-band theory of solids
Electronic structure
Ones gravitacionals
Grafè
Banda d'energia (Física)
Estructura electrònica
Àrees temàtiques de la UPC::Física::Relativitat
Descripción
Sumario:Strong correlations occur in magic-angle twisted bilayer graphene (MATBG) when the octet of flat moiré minibands centered on charge neutrality (CN) is partially occupied. The octet consists of a single valence band and a single conduction band for each of four degenerate spin-valley flavors. Motivated by the importance of Hartree electrostatic interactions in determining the filling-factor-dependent band structure, we use a time-dependent Hartree approximation to gain insight into electronic correlations. We find that the electronic compressibility is dominated by Hartree interactions, that paramagnetic states are stable over a range of density near CN, and that the dependence of energy on flavor polarization is strongly overestimated by mean-field theory.