Microwave electrodynamics of electron-doped cuprate superconductors

We report microwave cavity perturbation measurements of the temperature dep endence of the penetration depth, lambda>(*) over bar * (T), and conductivi ty, sigma>(*) over bar * (T) of Pr2-xCexCuO4-delta (PCCO) crystals, as well as parallel-plate resonator measurements of A(T) in PCCO thin films. Penet ration depth measurements are also presented for a Nd2-xCexCuO4-delta (NCCO ) crystal. We find that Deltah(T) has a power-law behavior for T < T-c/3, a nd conclude that the electron-doped cuprate superconductors have nodes in t he superconducting gap. Furthermore, using the surface impedance, we have d erived the real part of the conductivity, <sigma>(1)(T), below T-c and foun d a behavior similar to that observed in hole-doped cuprates.