Efficient momentum space approach to superconductivity in quasiperiodic systems

Superconductivity in quasiperiodic multilayer systems has attracted significant recent interests, including that in twisted bilayer graphene (TBG). While numerical studies on superconductivity in general multilayer heterostructures have been mainly based on the real space picture so far, its momentum space picture has less numerical cost and is desirable. Here, we develop an efficient momentum space approach to superconductivity in quasiperiodic systems, by including quasiperiodicity through the folding of Brillouin zones (BZs). We apply the BZ folding method to the SC state within bilayer systems and discuss how we can understand it through the BZ folding picture.