Discontinuity of capacitance at the onset of surface superconductivity

TL;DR

This paper investigates how a magnetic field causes a sudden change in capacitance at the onset of surface superconductivity, revealing a discontinuity linked to the electric field penetration depth.

Contribution

It demonstrates, using the Ginzburg-Landau theory, that capacitance exhibits a measurable discontinuity at the critical magnetic field for surface superconductivity in type-II superconductors.

Findings

Capacitance shows a discontinuity at the surface superconductivity onset.

Discontinuity related to electric field penetration depth.

Observable with current experimental setups for various superconductors.

Abstract

The effect of the magnetic field on a capacitor with a superconducting electrode is studied within the Ginzburg-Landau approach. It is shown that the capacitance has a discontinuity at the onset of the surface superconductivity $B_{\rm c3}$ which is expressed as a discontinuity in the penetration depth of the electric field into metals. Estimates show that this discontinuity is observable with recent bridges for both conventional and high-$T_{\rm c}$ superconductors of the type-II.