Spin Waves in Detwinned BaFe$_2$As$_2$

TL;DR

This study uses inelastic neutron scattering to map out spin excitations in fully detwinned BaFe$_2$As$_2$, revealing that an itinerant model with electronic correlations explains the magnetic behavior in this parent compound of iron-based superconductors.

Contribution

First complete mapping of spin excitations in fully detwinned BaFe$_2$As$_2$, providing insights into magnetic interactions relevant for superconductivity mechanisms.

Findings

Spin excitations are well described by an itinerant electronic model.

Electronic correlations play a significant role in spin dynamics.

Detwinning allows for clearer interpretation of magnetic spectra.

Abstract

Understanding magnetic interactions in the parent compounds of high-temperature superconductors forms the basis for determining their role for the mechanism of superconductivity. For parent compounds of iron pnictide superconductors such as $A$Fe$_2$As$_2$ ($A=$ Ba, Ca, Sr), although spin excitations have been mapped out throughout the entire Brillouin zone (BZ), measurements were carried out on twinned samples and did not allow for a conclusive determination of the spin dynamics. Here we use inelastic neutron scattering to completely map out spin excitations of $\sim$100\% detwinned BaFe$_2$As$_2$. By comparing observed spectra with theoretical calculations, we conclude that the spin excitations can be well described by an itinerant model with important contributions from electronic correlations.