Electronic Structure of Superconducting FeSe Studied by High-Resolution   Photoemission Spectroscopy
  We have performed soft x-ray and ultrahigh-resolution laser-excited photoemission measurements on tetragonal FeSe, which was recently identified as a superconductor. Energy dependent study of valence band is compared to band structure calculations and yields a reasonable assignment of partial densities of states. However, the sharp peak near the Fermi level slightly deviates from the calculated energy position, giving rise to the necessity of self-energy correction. We have also performed ultrahigh-resolution laser photoemission experiment on FeSe and observed the suppression of intensity around the Fermi level upon cooling. 
Rikiya Yoshida, Takanori Wakita, Hiroyuki Okazaki, Yoshikazu   Mizuguchi, Shunsuke Tsuda, Yoshihiko Takano, Hiroyuki Takeya,...