Quenching current by flux-flow instability in iron-chalcogenides thin films

TL;DR

This study investigates the flux-flow instability in iron-chalcogenide thin films, analyzing how quenching current relates to critical current under various conditions, and compares these properties with high-temperature cuprates to identify optimal materials for high-current applications.

Contribution

It provides new insights into the flux-flow instability and quenching current behavior in iron-based superconducting films, considering both intrinsic and extrinsic effects, and compares their performance with cuprates.

Findings

Quenching current differs from critical current, influenced by intrinsic and extrinsic mechanisms.

Analysis of current-voltage characteristics reveals the impact of magnetic field and temperature.

Comparison suggests iron-based superconductors as promising for high-temperature, high-field applications.

Abstract

The stability against quench is one of the main issue to be pursued in a superconducting material which should be able to perform at very high levels of current densities. Here we focus on the connection between the critical current $I_c$ and the quenching current $I^*$ associated to the so-called flux-flow instability phenomenon, which sets in as an abrupt transition from the flux flow state to the normal state. To this purpose, we analyze several current-voltage characteristics of three types of iron-based thin films, acquired at different temperature and applied magnetic field values. For these samples, we discuss the impact of a possible coexistence of intrinsic electronic mechanisms and extrinsic thermal effects on the quenching current dependence upon the applied magnetic field. The differences between the quenching current and the critical current are reported also in the case of predominant intrinsic mechanisms. Carrying out a comparison with high-temperature cuprate superconductors, we suggest which material can be the best trade-off between maximum operating temperature, higher upper critical field and stability under high current bias.