Impurity-induced resonance state as a probe of superconducting pairing symmetry in BiS$_{2}$-based superconductors

Within the two-orbital model for BiS2-based superconductors, the effect from a single nonmagnetic impurity scattering on the superconducting-state is investigated in terms of the T-matrix approach. By considering three kinds of the typical Fermi surface topology which characterize the essential features of the doping dependence of the electronic structure in BiS2-based superconductors, it is found that the impurity scattering on the superconducting-state with the conventional s-wave, the extended s-wave, the ±s-wave, and the dx2−y2 -wave symmetries induces qualitatively different resonance states due to the evolution of unique nodal structures on the Fermi surface with doping. These impurity-induced resonance states can be verified directly by the scanning tunneling microscopy experiments, and therefore they are proposed as a probe of the superconducting paring symmetry in BiS2-based superconductors.