The non-ohmic dissipation in type II planar superconductors at zero magnetic field

The non-ohmic response of type II planar superconductors at zero magnetic f ield is examined as a function of temperature and current. The data, from I -V characteristics reported in the literature, concern thin films and Josep hson junction arrays of metallic and high temperature superconductors. The overlapping of the R(T) dependence with a nondimensional temperature theta = (T - T-0(I))/(T - T-0(I)) is obtained, where T-0(I) and T, are the limits of the non-ohmic process. The R(theta) trend is well approximated by R = R o exp[-b root (1/theta). Such R(T,I) dependence appears to be a general fea ture in type II planar superconductors and it may be attributed to the curr ent assisted depairing of thermally excited vortex-antivortex pairs. (C) 20 00 Elsevier Science B.V. All rights reserved.