Experimental test of strong pinning and creep in current-voltage characteristics of type II superconductors

TL;DR

This paper tests strong pinning theory against experimental current-voltage data in type II superconductors, revealing how pinning and creep influence their electrical properties and potential for applications.

Contribution

It provides a quantitative analysis of superconductor properties using strong pinning theory, connecting experimental observations with theoretical predictions.

Findings

Voltage-onset shift and rounding match strong pinning theory with thermal fluctuations.

Identified parameters governing pinning and creep.

Experimental data supports the applicability of strong pinning theory.

Abstract

Pinning and creep determine the current--voltage characteristic of a type II superconductor and thereby its potential for technological applications. The recent development of strong pinning theory provides us with a tool to assess a superconductor's electric properties in a quantitative way. Motivated by the observation of typical excess-current characteristics and field-scaling of critical currents, here, we analyze current--voltage characteristics measured on 2H-NbSe$_2$ and $a$-MoGe type II superconductors within the setting provided by strong pinning theory. The experimentally observed shift and rounding of the voltage-onset is consistent with the predictions of strong pinning in the presence of thermal fluctuations. We find the underlying parameters determining pinning and creep and discuss their consistency.