COMPLEX RESISTIVITY OF YBa2Cu3O7-δ AT 48 GHz IN MAGNETIC FIELDS

Abstract

We present measurements of the magnetic field dependent complex resistivity at 48 GHz in a nearly-optimally doped thin YBa 2 Cu 3 O 7-δ film. Below Tc the application of the magnetic field leads to a detectable magnetoresistivity. The real part is clearly measurable from our lowest temperature up to Tc, while the imaginary part can be distinguished from zero only for T>87 K . The magnetoresistivity arises from the combined effects of fluxon motion and field-induced superfluid depletion. We discuss whether our data can be described or not by models for the magnetic response in an s-wave or d-wave superconductor.