Collective modes and emergent SO(6) symmetry in the iron pnictides

TL;DR

This paper reveals an emergent SO(6) symmetry in iron pnictides that unifies SDW and SC phases, predicts experimental signatures, and proposes a new orbital density wave state.

Contribution

It introduces an approximate SO(6) symmetry in low-energy models of iron pnictides, unifying magnetic and superconducting phenomena and predicting new experimental features.

Findings

Predicted resonant modes in neutron scattering experiments.

Outlined phase diagram topology based on SO(6) symmetry.

Proposed existence of an orbital density wave state.

Abstract

We show the existence of an emergent SO(6) symmetry in the low energy description of the iron pnictides. This approximate symmetry provides a unifying framework for the occurrence of spin density wave (SDW) and superconductivity (SC) in these materials. We use this symmetry to make several predictions for future experiments, including the topology of the phase diagram and the presence of various resonant modes in neutron scattering experiments in both the SC and SDW phases. We also predict the existence of a new "Orbital Density Wave" state, which competes with both SDW and SC orders.