Effect of hexagonal patterned arrays and defect geometry on the critical   current of superconducting films
  Understanding the effect of pinning on the vortex dynamics in superconductors is a key factor towards controlling critical current values. Large-scale simulations of vortex dynamics can provide a rational approach to achieve this goal. Here, we use the time-dependent Ginzburg-Landau equations to study thin superconducting films with artificially created pinning centers arranged periodically in hexagonal lattices. We calculate the critical current density for various geometries of the pinning centers --- varying their size, strength, and density. Furthermore, we shed light upon the influence of pattern distortion on the magnetic-field-dependent critical current. We compare our result directly with available experimental measurements on patterned molybdenum-germanium films, obtaining good agreement. Our results give important systematic insights into the mechanisms of pinning in these artificial pinning landscapes and open a path for tailoring superconducting films with desired critical current behavior. 
I. A. Sadovskyy, Y. L. Wang, Z.-L. Xiao, W.-K. Kwok, A. Glatz
cond-mat.supr-con cond-mat.mes-hall cond-mat.mtrl-sci physics.comp-ph