Scaling laws for the critical current density in anisotropic biaxial superconductors

TL;DR

This paper extends the scaling law for flux pinning anisotropy from uniaxial to biaxial superconductors, providing a unified description of critical current density behavior aligned with experimental observations.

Contribution

It introduces a generalized scaling law for flux-bundle collective pinning in biaxial superconductors, enhancing understanding of anisotropic critical current densities.

Findings

Critical current density follows a unified function with scaled isotropic superconductor behavior.

Angular dependence matches experimental observations.

Strong-pinning interactions may cause deviations from the model.

Abstract

To understand the anisotropy of flux pinning and critical current density in technological superconductors, the scaling law for the anisotropy of single-vortex collective pinning in uniaxial superconductors is extended to flux-bundle collective pinning in biaxial superconductors. The scaling results show that in a system of random uncorrected point defects, the critical current density is described by a unified function with the magnetic field of the scaled isotropic superconductor. The obtained angular dependence of the critical current density depicts the main features of experimental observations, considering possible corrections due to the strong-pinning interaction.