SUPERCONDUCTIVITY-INDUCED ANDERSON LOCALIZATION

We have studied the effect of a random superconducting order parameter on the localization of quasiparticles, by numerical finite-size scali ng of the Bogoliubov-de Gennes tight-binding Hamiltonian. Anderson loc alization is obtained in d = 2 and a mobility edge where the states lo calize is observed in d = 3. The critical behavior and localization ex ponent are universal within error bars both for real and complex rando m order parameter. Experimentally these results imply a suppression of thr electronic contribution to thermal transport from states above th e bulk energy gap.