Charge doping-induced quasiparticle scattering in iron-pnictide superconductors as probed by vortex pinning

TL;DR

This study investigates how charge doping in iron-pnictide superconductors causes quasiparticle scattering detectable through vortex pinning, revealing differences from isovalent doping and providing insights into scattering mechanisms.

Contribution

It demonstrates that charge doping induces collective vortex pinning via mean-free path fluctuations, enabling quantification of quasiparticle scattering rates in these materials.

Findings

Charge doping leads to flux vortex pinning via dopant-induced scattering.

Isovalent doping does not produce such vortex pinning effects.

The scattering rate correlates with charge doping levels.

Abstract

Charge doping of iron-pnictide superconductors leads to collective pinning of flux vortices, whereas isovalent doping does not. Moreover, flux pinning in the charge-doped compounds is consistently described by the mean-free path fluctuations introduced by the dopant atoms, allowing for the extraction of the elastic quasiparticle scattering rate. The absence of scattering by dopant atoms in isovalently doped BaFe$_{2}$(As$_{1-x}$P$_{x}$)$_{2}$ is consistent with the observation of a linear temperature dependence of the low-temperature penetration depth in this material.