Terahertz responses of high-resistivity YBCO thin films

[[abstract]]© 2003 Elsevier-We used pulse terahertz radiation to study the complex conductivity of high-resistivity YBCO thin films. The complex conductivity of YBCO superconducting thin films in the 50-300 GHz range was obtained. The temperature lambda(2)(0)/lambda(2) dependence of A (T) of such films exhibits a T-1 behavior which is closed to the prediction of the d-wave theory in the clean limit. However, its zero-temperature value is larger than that of typical high-quality single crystal YBCO. The temperature dependence of the real part of the conductivity below T, exhibits a frequency-dependent broad peak. Using the two-fluid Drude model for the superconducting state, the temperature dependence of the quasiparticle scattering rate is observed. The experimental result indicated that the quasiparticle scattering rate is higher than that reported on very-high-quality YBCO single crystals in the millimeter wave region. (C) 2003 Elsevier B.V. All rights reserved.[[department]]電機工程學