Flux flow and fluctuation resistivity at 48 GHz in high-Tc superconductors

The authors present measurements of the real part of the microwave resistivity at 48 GHz in YBa2Cu3O7-δ and Bi2Sr2CaCu2O8+x films, as a function of the temperature and of the static magnetic field. In zero field, the resistivity above the critical temperature is well described by the frequency-dependent fluctuational excess conductivity. In a static magnetic field and below Tc, the resistivity in YBa2Cu3O7-δ can be fully described by a simple flux-flow model, while in Bi2Sr2CaCu2O8+x this model applies only partially. The authors discuss possible alternative models