Pairing symmetry of twisted bilayer graphene: A phenomenological synthesis

The nature of the superconductor in twisted bilayer graphene has remained a mystery ever since its discovery. Microscopic theoretical approaches are difficult to control, and there has been no single decisive experiment able to completely fix the pairing symmetry. In spite of this, this work shows that by carefully drawing on information from a diverse array of existing experiments -- and using some minimal and general input from theory -- the nature of the pairing can be almost uniquely determined.