The Many-Body Ground State Manifold of Flat Band Interacting Hamiltonian for Magic Angle Twisted Bilayer Graphene
This work characterizes the ground state manifold for a flat band interacting Hamiltonian in magic angle twisted bilayer graphene. The study proves that ground states must be linear combinations of Slater determinants, each being a ground state of the Hamiltonian. It establishes constraints like uniform half-filling and uses symmetry, specifically hidden symmetries like U(4)xU(4), to determine the structure and dimension of these possible many-body states.