Renormalization group approach to interacting magic-angle twisted bilayer graphene

The experimental discovery of diverse interaction-driven phenomena in magic-angle twisted bilayer graphene (MATBG), including superconductivity and correlated insulating states, has established MATBG as a versatile platform for exploring strong correlation physics. Owing to the nontrivial topology, the MATBG mini bands cannot be described by a lattice model in two dimensions. A resolution is the topology heavy fermion model, where localized electrons in the flat band hybridize with itinerant topological electrons, providing a faithful low-energy description of MATBG. Using a perturbative renormalization group approach, we investigate the topological heavy fermion model to provide insights into how electronic interactions evolve over different energy and length scales, shedding light on the rich phase diagram of MATBG at low energies.