Effects of Dynamic External Pair Breaking in Superconducting Films

Abstract

Effects of dynamic external pair breaking in superconducting films are studied using microwave reflectivity to probe excess quasiparticle densities. For weak pair breaking, agreement with theory is good, permitting determination of effective quasiparticle recombination times. For strong pair breaking, an expected first-order transition to the normal state is not observed. Instead, a partially dc-resistive state is found in a broad injection region.