We develop a model to describe the mixed valence regime in magic-angle twisted bilayer graphene (MATBG) using the recently developed heavy-fermion framework. By employing the large-N slave-boson approach, we derive the self-consistent mean field equations and solve them numerically. We find that the SU(8) symmetry constraint moir\'e system exhibits novel mixed-valence properties which are different from conventional heavy-fermions systems. We find the solutions describing the physics at the filling near the Mott insulator regime in the limit of strong Coulomb interactions between the flat-band fermions. Our model can provide additional insight into the possible microscopic origin of unconventional superconductivity in MATBG.
@article{arxiv.2309.03416,
title = {Topological Mixed Valence Model in Magic-Angle Twisted Bilayer Graphene},
author = {Yantao Li and Benjamin M. Fregoso and Maxim Dzero},
journal= {arXiv preprint arXiv:2309.03416},
year = {2024}
}