Seaching for Moire flat bands in twisted bilayers of nodal materials

In twisted bilayer graphene (TBG), topological Dirac nodes can evolve to zero-energy flat bands as a critical playground for strongly correlated physics. Beyond TBG, considering different types of topological nodes in a variety of twisted bilayers and a direction-dependent interlayer coupling, we study the criteria for the emergence of flat bands in the Moire ´ Brillouin zone. Distinguished from TBG with two-fold degenerate flat bands, other bilayers with topological nodes can host two-fold degenerate as well as highly degenerate flat bands at different magic angles. The presence of multiple degeneracy flat bands in these systems may result in more rich correlation physics.