Fermi surface and band renormalization of Sr1-xKxFe2As2 from angle-resolved photoemission spectroscopy

High-resolution angle-resolved photoemission measurements have been carried out on the (Sr,K) Fe(2)As(2) superconductor (T(c) = 21 K). Three holelike Fermi-surface sheets are resolved around the Gamma point. One electronlike Fermi surface and strong Fermi spots are observed near the M(pi,pi) point which are different from a round electron pocket expected from band calculations. This discrepancy and the observed band renormalization ask for further theoretical effort in understanding the electronic structure of the Fe-based compounds.