Riedel Singularity in Sn—Sn-Oxide—Sn Josephson Tunnel Junctions

Abstract
An experimental study has been made of the Riedel singularity in Sn—Sn-Oxide—Sn Josephson tunnel junctions. The data indicate that gap anisotropy rather than quasiparticle damping is the dominant factor in rounding off the observed singularity. However, it appears feasible to use the singularity as a probe of quasiparticle damping effects.