Pearl vortices in anisotropic superconducting films

TL;DR

This paper investigates how anisotropy affects the magnetic field distribution of vortices in superconducting films, revealing sign changes and angular dependencies due to anisotropic London theory.

Contribution

It introduces an analysis of vortex magnetic fields in anisotropic superconducting films, highlighting sign changes and angular effects not present in isotropic models.

Findings

Magnetic field normal to the surface can change sign due to anisotropy.

Magnetic field decays as 1/r^3 at large distances, similar to isotropic films.

Anisotropy induces angular dependence in supercurrents and magnetic field sign changes for e > 2.

Abstract

The magnetic field of vortices in anisotropic superconducting films is considered in the framework of anisotropic London approach. It is found that at distances large relative to the core size, the magnetic field normal to the film surface may change sign. We find that the magnetic field attenuates at large distances as $1/r^3$ as it does in isotropic films, but the anisotropy induces an angular dependence to the supercurrents which causes the sign of the field to change for anisotropy parameters $\gamma=\lambda_2/\lambda_1>\sqrt{2}$ in some parts of the $(x,y)$ plane.