Abstract

One of the astonishing aspects of the cuprate high-temperature superconductors are their still unexplained conductance properties at temperatures above the superconducting transition temperature T_c. Simultaneous characterisation above and below T_c offers the possibility to test theories of superconductivity because any viable model must be able to account for the conductivity both in the superconducting and the normalconducting states. Here, we present a comparative study of the complex conductivity and the scattering behaviour of laser-ablated YBa₂Cu₃O_7-δ thin films at dc and THz frequencies for temperatures from 8K to 300K. The dependence of the conductivity on the density of the charge carriers (holes) in the CuO, planes is investigated by variation of the hole concentration via partial substitution of Y with Pr and via depletion of oxygen.

© 1996 Optical Society of America