Magnetism of magic-angle twisted bilayer graphene
Javad Vahedi, Robert Peters, Ahmed Missaoui, Andreas Honecker, Guy Trambly de Laissardière
SciPost Phys. 11, 083 (2021) · published 27 October 2021
- doi: 10.21468/SciPostPhys.11.4.083
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Abstract
We investigate magnetic instabilities in charge-neutral twisted bilayer graphene close to so-called "magic angles" using a combination of real-space Hartree-Fock and dynamical mean-field theories. In view of the large size of the unit cell close to magic angles, we examine a previously proposed rescaling that permits to mimic the same underlying flat minibands at larger twist angles. We find that localized magnetic states emerge for values of the Coulomb interaction $U$ that are significantly smaller than what would be required to render an isolated layer antiferromagnetic. However, this effect is overestimated in the rescaled system, hinting at a complex interplay of flatness of the minibands close to the Fermi level and the spatial extent of the corresponding localized states. Our findings shed new light on perspectives for experimental realization of magnetic states in charge-neutral twisted bilayer graphene.
Cited by 21
Authors / Affiliations: mappings to Contributors and Organizations
See all Organizations.- 1 Javad Vahedi,
- 2 Robert Peters,
- 3 Ahmed Missaoui,
- 3 Andreas Honecker,
- 3 Guy Trambly de Laissardière
- 1 Technische Universität Braunschweig / Braunschweig University of Technology
- 2 京都大学 / Kyoto University
- 3 CY Cergy Paris Université / CY Cergy Paris University
- Agence Nationale de la Recherche [ANR]
- Grand Équipement National De Calcul Intensif (through Organization: Grand Equipement National de Calcul Intensif [GENCI])
- 日本学術振興会 / Japan Society for the Promotion of Science [JSPS]