High-resolution angle-resolved photoemission spectroscopy study of the electronic structure ofEuFe2As2

Abstract

We report the high-resolution angle-resolved photoemission spectroscopy studies of electronic structure of ${\text{EuFe}}_{2}{\text{As}}_{2}$. The paramagnetic state data are found to be consistent with density-functional calculations. In the antiferromagnetic ordering state of Fe, our results show that the band splitting, folding, and hybridization evolve with temperature, which cannot be explained by a simple folding picture. Detailed measurements reveal that a tiny electron Fermi pocket and a tiny hole pocket are formed near $(\ensuremath{\pi},\ensuremath{\pi})$ in the $(0,0)\ensuremath{-}(\ensuremath{\pi},\ensuremath{\pi})$ direction, which qualitatively agree with the results of quantum oscillations, considering ${k}_{z}$ variation in Fermi surface. Furthermore, no noticeable change within the energy resolution is observed across the antiferromagnetic transition of ${\text{Eu}}^{2+}$ ordering, suggesting weak coupling between Eu sublattice and FeAs sublattice.