Comparatively High In-Field Critical Current in Type-II Superconductors from Heterogeneous Columnar Pins: A Molecular Dynamics Study

TL;DR

This study uses molecular dynamics and theoretical analysis to show that heterogeneous columnar pins significantly enhance the in-field critical current in type-II superconductors, especially due to antipin components.

Contribution

It introduces a combined theoretical and simulation approach to quantify how heterogeneous columnar pins improve critical current in superconductors.

Findings

Antipin components substantially increase critical current.

Heterogeneous columnar pins outperform homogeneous pins.

Both theory and simulation agree on the importance of antipins.

Abstract

Theoretical work predicts that the strong dependence of Tc on pure shear strain within the a-b plane of optimally doped YBa2Cu3O{7-delta} 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.