Vortex pinning in anisotropic Josephson junction arrays

We have investigated the effect of anisotropy on vortex motion in the proximity effect junction array. We introduced the anisotropy to square lattice junction arrays by changing the Josephson coupling energy between longitudinal and transverse junctions. The potential barrier height for a vortex has been estimated from the current dependence of the resistance of the array under magnetic fields. We have found that the potential barrier drastically depends on the anisotropy of the system. We also performed numerical calculations for the potential barrier, and successfully reproduced the experimental results. These results indicate that the anisotropy dramatically affects the vortex motion reflecting the change of pinning potential. (C) 2000 Elsevier Science B.V. All rights reserved.