Unusual band renormalization in the simplest iron based superconductor

TL;DR

This study uses ARPES to reveal unusual orbital-dependent band renormalization in FeSe_{1-x}, highlighting significant differences from DFT predictions and other iron-based superconductors, advancing understanding of its electronic structure.

Contribution

It provides the first detailed ARPES analysis of FeSe_{1-x} showing unique orbital-dependent band renormalization not seen in related compounds.

Findings

Pronounced orbital-dependent band renormalization in FeSe_{1-x}

Significant discrepancies between experimental data and DFT calculations

Differences from other iron-based superconductors

Abstract

The electronic structure of the iron chalcogenide superconductor FeSe_{1-x} was investigated by high- resolution angle-resolved photoemission spectroscopy (ARPES). The results were compared to DFT calculations showing some significant differences between the experimental electronic structure of FeSe_{1-x}, DFT calculations and existing data on FeSe_{x}Te_{1-x}. The bands undergo a pronounced orbital dependent renormalization, different from what was observed for FeSe_{x}Te_{1-x} and any other pnictides.