Multiple flux jumps and irreversible behavior of thin Al superconducting rings

TL;DR

This paper investigates flux jumps and irreversible magnetization in mesoscopic aluminum superconducting rings, revealing metastable states and defect effects, using experimental data and time-dependent Ginzburg-Landau theory for explanation.

Contribution

It provides a combined experimental and theoretical analysis of flux jumps and metastability in mesoscopic superconducting rings, highlighting defect influence and vorticity changes.

Findings

Flux jumps can exceed unity change in vorticity.

Defects significantly affect flux jump size.

Time-dependent Ginzburg-Landau model semi-quantitatively explains results.

Abstract

An experimental and theoretical investigation was made of flux jumps and irreversible magnetization curves of mesoscopic Al superconducting rings. In the small magnetic field region the change of vorticity with magnetic field can be larger than unity. This behavior is connected with the existence of several metastable states of different vorticity. The intentional introduction of a defect in the ring has a large effect on the size of the flux jumps. Calculations based on the time-dependent Ginzburg-Landau model allows us to explain the experimental results semi-quantitatively.