Band Structure and Fermi Surface of an Extremely Overdoped Iron-Based SuperconductorKFe2As2

T. Sato, K. Nakayama, Y. Sekiba, P. Richard, Y.-M. Xu, S. Souma, T. Takahashi, G. F. Chen, J. L. Luo, N. L. Wang, H. Ding
2009 Physical Review Letters  
We have performed high-resolution angle-resolved photoemission spectroscopy on heavily overdoped KFe_2As_2 (transition temperature (Tc = 3 K). We observed several renormalized bands near the Fermi level with a renormalization factor of 2-4. While the Fermi surface (FS) around the Brillouin-zone center is qualitatively similar to that of optimally-doped Ba_{1-x}K_xFe_2As_2 (x = 0.4; Tc = 37 K), the FS topology around the zone corner (M point) is markedly different: the two electron FS pockets
more » ... ctron FS pockets are completely absent due to excess of hole doping. This result indicates that the electronic states around the M point play an important role in the high-Tc superconductivity of Ba$_{1-x}$K$_x$Fe$_2$As$_2$ and suggests that the interband scattering via the antiferromagnetic wave vector essentially controls the Tc value in the overdoped region.
doi:10.1103/physrevlett.103.047002 pmid:19659391 fatcat:fzwqx7vkibefrmgbyhqkoihdxi