Instability of vortex-antivortex interface in optimally-doped Ba(Fe_{1-x}Co_{x})_{2}As_{2}

TL;DR

This paper investigates the turbulent instability at the vortex-antivortex interface in an iron-based superconductor, revealing potential universal behavior in remagnetized type-II superconductors.

Contribution

It demonstrates the presence of turbulent flux boundary instability in Ba(Fe_{1-x}Co_{x})_{2}As_{2} and compares it with cuprate superconductors, suggesting a common feature.

Findings

Turbulent dynamics observed at vortex-antivortex boundary after remagnetization.

A band of excess current density associated with the turbulence.

Comparison indicates similar instabilities in cuprate superconductors.

Abstract

We explore the flux front patterns during virgin penetration and after remagnetization in the iron-based superconductor Ba(Fe_{1-x}Co_{x})_{2}As_{2}. After remagnetization we observe an instability characterized by turbulent dynamics at the vortex-antivortex boundary. Associated with the turbulent flux boundary a band of excess current density is observed. The turbulence is contrasted with the instability observed in the cuprate superconductors. Our results suggest turbulent instability at the vortex-antivortex interface may be a common feature in all remagnetized type-II superconductors.