Influence of the confinement geometry on surface superconductivity

TL;DR

This paper investigates how the shape and size of mesoscopic superconducting samples influence the surface nucleation field, revealing that geometrical confinement can significantly enhance surface superconductivity, especially in wedge-shaped geometries.

Contribution

It provides a detailed analysis of how different geometries affect the nucleation field, including a divergence in wedge shapes as the angle decreases, highlighting the role of confinement in surface superconductivity.

Findings

Nucleation field depends on sample geometry and size.

Wedge shapes exhibit diverging nucleation fields as the wedge angle decreases.

Surface superconductivity can be substantially enhanced by geometrical confinement.

Abstract

The nucleation field for surface superconductivity, $H_{c3}$, depends on the geometrical shape of the mesoscopic superconducting sample and is substantially enhanced with decreasing sample size. As an example we studied circular, square, triangular and wedge shaped disks. For the wedge the nucleation field diverges as $H_{c3}/H_{c2}=\sqrt{3}/\alpha$ with decreasing angle ($\alpha$) of the wedge, where $H_{c2}$ is the bulk upper critical field.