Vortex pinning and motion in randomly frustrated Josephson-junction arrays

The current-voltage characteristics of a positionally disordered supercondu cting Josephson-junction network are investigated numerically. An efficient algorithm is proposed which enables one to simulate networks with up to 10 24 x 1024 nodes. The I-V curves are highly nonlinear in the ordered phase. For a given temperature and external current, it is observed that the resis tivity increases with disorder strength. This is in contrast to the behavio ur of type-II superconductors in the mixed state where disorder reduces the resistivity through vortex pinning. (C) 2000 Published by Elsevier Science B.V. All rights reserved.