Domain Walls in Normal and Superconducting States of Iron Pnictides

TL;DR

This paper investigates how strong electron correlations induce different types of domain walls in iron pnictides, affecting their magnetic and electronic structures in both normal and superconducting states.

Contribution

It introduces a self-consistent Bogoliubov-de Gennes approach to study domain walls and reveals their doping-dependent types and properties in iron pnictides.

Findings

90° domain walls at low doping

Anti-phase domain walls at high doping

Domain walls have higher electron densities

Abstract

The electronic and magnetic structures in the normal and superconducting states of iron pnictides are investigated by solving self-consistently the Bogoliubov-de Gennes equation. It is shown that strong electron correlations can induce domain walls, which separate regions with different spin density wave orders. At zero or low electron doping, $90^\circ$ domain walls are formed while anti-phase domain walls are produced at higher electron doping. On the domain walls, larger electron densities are always present. The results agree qualitatively with recent observations of scanning tunneling microscopy and superconducting quantum interference device microscopy.