Reentrant temperature dependence of the critical current in small tunnel junctions

Abstract

We have observed an anomalous decrease of the measured Josephson critical current as temperature is decreased below 0.85${T}_{c}$ on small Sn-SnOx-Sn tunnel junctions. The results of analog and dig- ital simulations over a wide range of junction noise and damping parameters suggest that this anomalous temperature dependence of the critical current could be caused by the strongly temperature-dependent damping effect of the quasiparticle tunnel resistance below the gap voltage.