Optical response of superconducting YBa2Cu3O7-delta thin films and grain boundaries

摘要

Abstract: We have investigated the optical response of single grain-boundary weak-links in superconducting YBCO thin films. At the superconducting transition of a film containing a single grain-boundary weak-link we observed an enhanced optical response from the weak- link. Below the transition temperature, we measure the bias current and the temperature dependence of the optical response of the grain-boundary in the temperature range of 15 K $LS T $LS 80 K. Using a Resistively-Shunted-Junction model for the grain-boundary weak- link, we find that the optical response in this temperature range can be described by radiation induced thermal modulation of the critical currents.!24