Josephson fluxon flow and phase diffusion in thin-film intrinsic Josephson junctions

We have measured the transport properties of intrinsic Josephson junction arrays as a function of both temperature and magnetic field, the field being applied perpendicular to the transport current. We show that they depend upon whether the junction width exceeds or is less than the Josephson penetration depth. For widths greater than the Josephson penetration depth, the transport properties are dominated by Josephson vortex flow. For widths less than the Josephson penetration depth, the zero-field dissipation is dominated by Josephson phase diffusion. For non-zero applied fields, there is a good fit to the classical “Fraunhofer” dependence of the critical current upon field in addition to a competition between Josephson phase diffusion and Josephson vortex flow.