2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/222785We show, using a simple model, how ordinary disorder can gap an extended-$s$ ($A_{1g}$) symmetry superconducting state with nodes. The concommitant 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.9 pagesSuperconductivityStrongly Correlated Electronstext