Enhanced critical currents in high-temperature superconductors with splayed pins

Using realistic three-dimensional computer simulations, we consider the effects of point, columnar, and splayed columnar pinning on vortex transport. We find an enhancement in the critical current when columnar pins are placed in a splayed configuration rather than parallel to each other, but that this enhancement is limited to the vortex creep regime at the lowest measurable applied currents. At higher currents, in the vortex flow regime, the enhancement by splay is lost. (C) 2000 Elsevier Science B.V. All rights reserved.