ac resistivity ofd-wave ceramic superconductors

We model d-wave ceramic superconductors with a three-dimensional lattice of randomly distributed π Josephson junctions with finite self-inductance. The linear and nonlinear ac resistivity of the d-wave ceramic superconductors is obtained as a function of temperature by solving the corresponding Langevin dynamical equations. We find that the linear ac resistivity remains finite at temperature Tₚ where the third harmonics of resistivity has a peak. The current amplitude dependence of the nonlinear resistivity at the peak position is found to be a power law. These results agree qualitatively with experiments. We also show that the peak of the nonlinear resistivity is related to the onset of the paramagnetic Meissner effect which occurs at the crossover temperature Tₚ, which is above the chiral glass transition temperature Tcg.