Antiferromagnetism enables electron-phonon coupling in iron-based superconductors

TL;DR

This paper demonstrates that antiferromagnetism in iron-based superconductors activates strong electron-phonon coupling channels that are otherwise canceled out in the nonmagnetic state, highlighting the role of magnetic order in superconductivity.

Contribution

It reveals how antiferromagnetic order enables electron-phonon coupling in iron-based superconductors through symmetry considerations and Fermi surface analysis.

Findings

Antiferromagnetism opens strong electron-phonon coupling channels.

In the nonmagnetic state, these channels cancel out.

Relevance to iron-based pnictide and chalcogenide superconductors.

Abstract

It is shown that a generic form of an antiferromagnetic wave function opens strong electron-phonon coupling channels in the iron-based superconductors. In the nonmagnetic state these channels exist locally on a single iron atom, but are canceled out between the two iron atoms in the primitive unit cell. Our findings are based on symmetry and the presence of an xz/yz Fermi surface near the M point and thus should be relevant for the known iron-based pnictide or chalcogenide superconductors.