TITLE : Superconductivity and magic-angle renormalization in twisted bilayer graphene
ABSTRACT :
We employ an atomistic tight-binding model to address basic properties of magic-angle twisted bilayer graphene within Hartree-Fock theory. We introduce a novel set of local order parameters that capture the symmetry-breaking patterns of various correlated states [1]. Furthermore, we obtain the mean-field normal state at the charge neutrality point [2], revealing a nontrivial renormalization of the band structure and a corresponding shift in the value of the magic angle. We then extract the numerical values for the parameters of a generalized Bistritzer-MacDonald model based on this normal state, establishing a low-energy description which incorporates lattice relaxation and many-body effects from high-energy states. Finally, we discuss the implications for experiments. References: [1]Miguel Sánchez Sánchez, Israel Díaz, José González, and Tobias Stauber, Nematic versus Kekulé phases in twisted bilayer graphene under hydrostatic pressure. Phys. Rev. Lett. 133, 266603 (2024) [2]Miguel Sánchez Sánchez, José González, and Tobias Stauber, Nonflat bands and chiral symmetry in magic-angle twisted bilayer graphene. Phys. Rev. B 111, 205133 (2025)
MEETING DETAILS :
Speaker: Dr. Tobias Stauber, Instituto de Ciencia de Materiales de Madrid, CSIC, Spain
Venue: A4 Conference room, South Campus, IIT Mandi
Date and Time: June 30, 2025, Monday at 12 PM