Enhancing Critical Current Density in Thin Superconductor Layers by Moir\'e Pinning Centers

TL;DR

This paper investigates how moiré patterned pinning centers can significantly enhance the critical current density in thin superconducting layers through molecular dynamics simulations.

Contribution

It introduces the use of moiré patterned pinning centers and demonstrates their effectiveness in increasing critical current density compared to primary lattice pinning.

Findings

Critical current density is significantly enhanced at specific rotation angles.

Stronger pinning forces lead to higher critical current densities in moiré lattices.

Moiré lattices outperform primary lattices in pinning effectiveness.

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 moir\'e 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 vortices dynamics are 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 moir\'e lattices compared to the primary lattices of pinning centers.