Probing unconventional superconductivity in proximitized graphene by impurity scattering

We demonstrate how potential impurities are a very powerful tool for determining the pairing symmetry in graphene, proximity coupled to a spin-singlet superconductor. All $d$-wave states are characterized by subgap resonances, with spatial patterns clearly distinguishing between nodal and chiral $d$-wave symmetry, while $s$-wave states have no subgap resonances. We also find strong supergap impurity resonances associated with the normal state Dirac point. Subgap and supergap resonances only interact at very low doping levels, then causing suppression of the supergap resonances.