We report the high-resolution angle-resolved photoemission spectroscopy studies of electronic structure of EuFe2As2. 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 (pi,pi) in the (0,0)-(pi,pi) direction, which qualitatively agree with the results of quantum oscillations, considering kz variation of Fermi surface. Furthermore, no noticeable change within the energy resolution is observed across the antiferromagnetic transition of Eu2+ ordering, suggesting weak coupling between Eu sublattice and FeAs sublattice.
@article{arxiv.1001.4537,
title = {High-resolution angle-resolved photoemission spectroscopy study of the electronic structure of EuFe2As2},
author = {Bo Zhou and Yan Zhang and Le-Xian Yang and Min Xu and Cheng He and Fei Chen and Jia-Feng Zhao and Hong-Wei Ou and Jia Wei and Bin-Ping Xie and Tao Wu and Gang Wu and Masashi Arita and Kenya Shimada and Hirofumi Namatame and Masaki Taniguchi and X. H. Chen and D. L. Feng},
journal= {arXiv preprint arXiv:1001.4537},
year = {2010}
}