ARPES observation of Mn-pnictide hybridization and negligible band structure renormalization in BaMn$_2$As$_2$ and BaMn$_2$Sb$_2$

TL;DR

This study uses ARPES to investigate BaMn$_2$As$_2$ and BaMn$_2$Sb$_2$, revealing a $k_z$-dependent band gap, minimal band renormalization, and Mn-pnictide hybridization, contributing to understanding their electronic structure.

Contribution

It provides the first detailed ARPES analysis of these Mn-pnictides, highlighting their weak correlation effects and hybridization phenomena.

Findings

Presence of a $k_z$-dependent band gap with a minimum at the Brillouin zone center

Almost no band structure renormalization from DFT calculations

Evidence of Mn-pnictide hybridization affecting electronic correlations

Abstract

We performed an angle-resolved photoemission spectroscopy study of BaMn$_2$As$_2$ and BaMn$_2$Sb$_2$, which are isostructural to the parent compound BaFe$_2$As$_2$ of the 122 family of ferropnictide superconductors. We show the existence of a strongly $k_z$-dependent band gap with a minimum at the Brillouin zone center, in agreement with their semiconducting properties. Despite the half-filling of the electronic 3$d$ shell, we show that the band structure in these materials is almost not renormalized from the Kohn-Sham bands of density functional theory. Our photon energy dependent study provides evidence for Mn-pnictide hybridization, which may play a role in tuning the electronic correlations in these compounds.