Resistively and capacitively shunted Josephson junctions model for unconventional superconductors

An array of resistively and capacitively shunted Josephson junctions with nonsinusoidal current- phase relation is considered for modelling the resistive transition in high-T_c superconductors. The emergence of higher harmonics, besides the sinusoid I_c sin φ, is expected for dominant d-wave symmetry of the Cooper pairs, random distribution of potential drops and dirty grains, or in nonstationary conditions. We show that additional cosine term acts by modulating the global resistance, due to the weak-links whose transition occurs through mixed superconductive-normal states.