V. Mishra, G. Boyd, S. Graser, T. Maier, P. J. Hirschfeld, and D. J. Scalapino, Lifting of nodes by disorder in extended-s-state superconductors: Application to ferropnictides
Phys. Rev. B 79, 094512, 2009-03-11
Abstract : We show, using a simple model, how ordinary disorder can gap an extended-s- (A1g) symmetry superconducting state with nodes. The concomitant crossover of thermodynamic properties, particularly the T dependence of the superfluid density, from pure power-law behavior to an activated one is exhibited. We discuss applications of this scenario to experiments on the ferropnictide superconductors.