Exact Many-Body Ground States in Chiral Twisted Bilayer Graphene

In recent years, twisted bilayer graphene (TBG) has drawn immense interest due to the experimental observation of strongly correlated superconducting and correlated insulating states in this material. A closer study of interacting models for TBG has revealed a remarkable observation: despite the presence of strong electron-electron interactions, at integer fillings the ground states of TBG are well described by Hartree-Fock theory - especially so in the chiral model. In this talk, I will discuss our recent results which rigorously establish this property of the chiral model: For chiral TBG at integer fillings, a state is a ground state if and only if it can be written as a superposition of Hartree-Fock states, all of which have the same energy.