MAGNETIC PINNING BY PLANAR DEFECTS IN TYPE-II SUPERCONDUCTORS

The magnetic interaction between a vortex and a planar defect with a finite width is studied using the London approximation. The penetration depth inside the defect is assumed to vary spatially and the vortex to run parallel to the defect. It is found that the planar defect influences the field and current distributions of the vortex significantly. An interference effect appears as a result of the presence of two planar boundaries. When the vortex is situated near the planar defect. a large pinning force arises due to the redistribution of the circular current around the vortex core. Both the pinning potential and the pinning force can be of the same order as those of the core pinning. The pinning force is largest when the width of the defect is nearly 4xi.