Review of the multilayer coating model

TL;DR

This paper reviews a theoretical model of multilayer coatings, highlighting how magnetic-field attenuation and vortex-penetration fields differ from simpler models, and discusses optimal layer configurations for superconducting applications.

Contribution

It provides a comprehensive review of the multilayer-coating model, emphasizing the impact of material properties and layer thicknesses on magnetic-field limits.

Findings

Smaller penetration depth materials like Nb improve vortex-penetration fields.

The field limit depends on both superconductor and substrate properties.

Optimal layer thicknesses can be determined from contour plots of the model.

Abstract

The recent theoretical study on the multilayer-coating model published in Applied Physics Letters [1] is reviewed. Magnetic-field attenuation behavior in a multilayer coating model is different from a semi-infinite superconductor and a superconducting thin film. This difference causes that of the vortex-penetration field at which the Bean-Livingston surface barrier disappears. A material with smaller penetration depth, such as a pure Nb, is preferable as the substrate for pushing up the vortex-penetration field of the superconductor layer. The field limit of the whole structure of the multilayer coating model is limited not only by the vortex-penetration field of the superconductor layer, but also by that of the substrate. Appropriate thicknesses of superconductor and insulator layers can be extracted from contour plots of the field limit of the multilayer coating model given in Ref.[1].