Single nonmagnetic impurity resonance in FeSe-based 122-type superconductors as a probe for pairing symmetry
Department of Physics and Center of Theoretical and Computational Physics, The University of Hong Kong Hong Kong, China
Received: 30 November 2012
Accepted: 13 February 2013
We study the effect of a single nonmagnetic impurity in AyFe2−xSe2 (A = K, Rb, or Cs) superconductors by considering various pairing states based on a three-orbital model consistent with the photoemission experiments. The local density of states on and near the impurity site has been calculated by solving the Bogoliubov-de Gennes equations self-consistently. The impurity-induced in-gap bound states are found only for attractive impurity scattering potential, as in the cases of doping of Co or Ni, which is characterized by the strong particle-hole asymmetry, in the nodeless dx2−y2 wave pairing state. This property may be used to probe the pairing symmetry of FeSe-based 122-type superconductors.
PACS: 74.70.Xa – Pnictides and chalcogenides / 74.62.En – Effects of disorder / 74.20.Pq – Electronic structure calculations
© EPLA, 2013