Year: 2023
Type: article
Abstract: This study discusses the effect of long‐range interactions within the self‐consistent Hartree‐Fock (HF) approximation in comparison to short‐range atomic Hubbard interactions on the band structure of twisted bilayer graphene (TBG) at charge neutrality for various twist angles. Starting from atomistic calculations, it determines the quasi‐particle band structure of TBG with Hubbard interactions for three magnetic orderings: modulated anti‐ferromagnetic (MAFM), (NAFM) and hexagonal anti‐ferromagnetic (HAFM). Then, it develops an approach to incorporate these magnetic orderings along with the HF potential in the continuum approximation. Away from the magic angle, it observes a drastic effect of the magnetic order on the band structure of TBG compared to the influence of the HF potential. Near the magic angle, the HF potential plays a major role in the band structure, with HAFM and MAFM being secondary effects, but NAFM appears to still significantly distort the electronic structure at the magic angle. These findings suggest that the spin‐valley degenerate broken symmetry state often found in HF calculations of charge neutral TBG near the magic angle should favor magnetic order, since the atomistic Hubbard interaction will break this symmetry in favor of spin polarization.
Source: Advanced Physics Research
Institutions: IMDEA Nanoscience, Harvard University, Thomas Young Centre, Imperial College London, University of Trieste, Universität Hamburg, Jülich Aachen Research Alliance, Center for Free-Electron Laser Science, Max Planck Institute for the Structure and Dynamics of Matter, RWTH Aachen University, Donostia International Physics Center
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,450
Funders: Comunidad de Madrid, Ministerio de Ciencia, Innovación y Universidades, Graphene Flagship, Imperial College London, European Commission, Deutsche Forschungsgemeinschaft, Thomas Young Centre, Ministerio de Ciencia e Innovación, Directorate-General for Research and Innovation, Horizon 2020 Framework Programme, Engineering and Physical Sciences Research Council
Awards: G2579223776, G2697776615, EPSRC Centre for Doctoral Training in Theory and Simulation of Materials, G3451526285, G4696143545, G5323274149, Mikroskopische Beschreibung von Korrelationseffekten in verdrehten van der Waals [Hetero]Strukturen, G6575300535, Discovering twisted bilayer materials with strong electron correlations, EXC 2004: Materie und Licht für Quanteninformation (ML4Q)
OpenAlex ID: W4385791805