Detection of antiferromagnetic ordering in heavily doped LaFeAsO1-xHx pnictide superconductors using nuclear-magnetic-resonance techniques

TL;DR

This study reveals a new antiferromagnetic phase in heavily doped LaFeAsO1-xHx superconductors, discovered via nuclear magnetic resonance, which follows the double superconducting domes and is linked to electron pocket nesting.

Contribution

It uncovers a previously unreported antiferromagnetic phase in heavily doped LaFeAsO1-xHx, expanding understanding of magnetic ordering in high-Tc pnictides.

Findings

Discovery of a new AF phase following double SC domes.

AF ordering originates from electron pocket nesting.

The phase is unique among high-Tc pnictides due to doping capability.

Abstract

We studied double superconducting (SC) domes in LaFeAsO1-xHx by using 75As- and 1H-nuclear magnetic resonance techniques, and unexpectedly discovered that a new antiferromagnetic (AF) phase follows the double SC domes on further H doping, forming a symmetric alignment of AF and SC phases in the electronic phase diagram. We demonstrated that the new AF ordering originates from the nesting between electron pockets, unlike the nesting between electron and hole pockets as seen in the majority of undoped pnictides. The new AF ordering is derived from the features common to high-Tc pnictides: however, it has not been reported so far for other high-Tc pnictides because of their poor electron doping capability.