Nature of Superconductivity in Twisted Bilayer Graphene

When two sheets of van der Waals material are twisted with respect to each other, it creates intricate superlattice structures known as moire patterns. These moire materials have become a hot topic of research in the strongly correlated community due to their rich quantum phases such as superconductivity, correlated insulating states, topological bands, etc. Twisted bilayer graphene is one of the moire family which shows robust superconductivity dome only for carrier densities 2 < |n/n_s| <3. We use this fact to constrain the nature of the superconducting phase and possible mechanisms that can drive the superconductivity in this material.