Local magnetization nucleated by non-magnetic impurities in Fe-based superconductors

TL;DR

This paper investigates how non-magnetic impurities can induce local magnetic order in iron-based superconductors by analyzing a five-band Hubbard model, revealing the conditions under which impurity-induced magnetism occurs.

Contribution

It provides a detailed phase diagram showing the dependence of impurity-induced magnetization on impurity strength and Coulomb interactions, explaining the phenomenon through impurity resonance behavior.

Findings

Impurity-induced magnetism exists within a specific range of impurity potential strengths.

Local magnetic order is linked to impurity-enhanced states near the Fermi level.

The phase diagram maps the conditions for impurity-induced magnetization.

Abstract

We study impurity-induced magnetic order within a five-band Hubbard model relevant to the normal paramagnetic phase of iron-based superconductors. The existence of the local magnetic order is explained in terms of an impurity-enhancement of states near the Fermi level, and we map out the resulting phase diagram of the existence of magnetization as a function of impurity strength and Coulomb correlations. In particular, the presence of impurity-induced magnetism in only a certain range of potential scattering strengths can be understood from the specific behavior of the impurity resonant state.