Enhancing Critical Current Density in Thin Superconductor Layers by Moiré Pinning Centers

Abstract

One important factor affecting the critical current density in type-II superconductors is the formation of artificial pinning centers. Hence, the engineering of pinning centers in superconducting systems has garnered considerable attention. In this study, the effect of moiré patterned pinning centers on the critical current density of superconducting tapes is investigated. The Langevin equation is solved by taking into account the prominent forces within the superconductor medium, using the appropriate boundary conditions for vortices. The vortex dynamics is investigated by performing molecular dynamics simulations, which are used to calculate the corresponding critical current densities. Results show a significant enhancement in the critical current density at particular angles of the relative rotation of the primary lattices. It is also revealed that for stronger pinning forces, the calculated critical current densities are higher in the moiré lattices compared to the primary lattices of pinning centers.