Quantum oscillations in the parent pnictide BaFe$_2$As$_2$ : itinerant electrons in the reconstructed state

TL;DR

This study uses quantum oscillation measurements to directly observe the Fermi surface of BaFe$_2$As$_2$, revealing a reconstructed Fermi surface in the antiferromagnetic state with itinerant electrons, consistent with band folding models.

Contribution

It provides direct experimental evidence of the reconstructed Fermi surface in BaFe$_2$As$_2$'s antiferromagnetic state, supporting a band folding interpretation.

Findings

Fermi surface is reconstructed in the antiferromagnetic state

Itinerant electrons persist in the reconstructed state

Results support a band folding model of the ground state

Abstract

We report quantum oscillation measurements that enable the direct observation of the Fermi surface of the low temperature ground state of \ba122. From these measurements we characterize the low energy excitations, revealing that the Fermi surface is reconstructed in the antiferromagnetic state, but leaving itinerant electrons in its wake. The present measurements are consistent with a conventional band folding picture of the antiferromagnetic ground state, placing important limits on the topology and size of the Fermi surface.