Comparatively high in-field critical current in type-II superconductors from heterogeneous columnar pins: A molecular dynamics study

Theoretical work predicts that the strong dependence of Tc on pure shear strain within the a-b plane of optimally doped YBa2Cu3O7−δ results in heterogenous columnar pins of vortex lines about dislocation lines and about nano-columns inclusions aligned in parallel to the c axis. The critical current of a rigid vortex lattice driven by the Lorentz force in the presence of such clusters of pin/antipin lines is computed using two-dimensional (2D) collective pinning theory and by numerical simulation of the corresponding 2D vortex dynamics. Both theory and computer calculation find that the antipin component of the heterogenous columnar pins contributes substantially to the net in-field critical current.