Orbital-dependent modifications of electronic structure across magneto-structural transition in BaFe2As2

TL;DR

This study uses laser ARPES to reveal how the electronic structure of BaFe2As2 changes across its magneto-structural transition, highlighting orbital-dependent modifications and Fermi surface transformations.

Contribution

It provides the first detailed observation of orbital-dependent electronic structure changes across the transition in BaFe2As2 using ARPES.

Findings

Fermi surface shape drastically changes across TN

Low-temperature FS dominated by Fe3dzx orbital

Magneto-structural transition involves orbital-dependent modifications

Abstract

Laser angle-resolved photoemission spectroscopy (ARPES) is employed to investigate the temperature (T) dependence of the electronic structure in BaFe2As2 across the magneto-structural transition at TN ~ 140 K. A drastic transformation in Fermi surface (FS) shape across TN is observed, as expected by first-principles band calculations. Polarization-dependent ARPES and band calculations consistently indicate that the observed FSs at kz ~ pi in the low-T antiferromagnetic (AF) state are dominated by the Fe3dzx orbital, leading to the two-fold electronic structure. These results indicate that magneto-structural transition in BaFe2As2 accompanies orbital-dependent modifications in the electronic structure.