Surface chiral superconductivity in odd-parity nematic superconductors with magnetic impurities

We study odd-parity nematic superconductivity in doped topological insulators in the presence of surface magnetic impurities. The peculiar surface subgap spectrum, characterized by a Majorana flat band, nodal cones, and the surface states of the parent topological insulator, gives rise to overall ferromagnetic RKKY interactions between the surface impurities. An additional coupling between the impurities and a preemptive chiral order parameter promote a surface time-reversal symmetry breaking solution at the surface of the system. We discuss the relevant scenarios and suggest to engineer surface chiral superconductivity by properly choosing magnetic adatoms with highly anisotropic exchange coupling.