"Fermi surfaces and quasi-particle band dispersions of the iron pnictides superconductor KFe2As2 observed by angle-resolved photoemission spectroscopy"

T. Yoshida: I. Nishi, A. Fujimori, M. Yi, R.G. Moore, D.-H. Lu, Z.-X. Shen, K. Kihou, P.M. Shirage, H. Kito, C.H. Lee, A. Iyo, H. Eisaki, and H. Harima; Journal of Physics and Chemistry of Solids, 05/02/11.

Additional Authors: I. Nishi, A. Fujimori, M. Yi, R.G. Moore, D.-H. Lu, Z.-X. Shen, K. Kihou, P.M. Shirage, H. Kito, C.H. Lee, A. Iyo, H. Eisaki, and H. Harima

Abstract:

We have performed an angle-resolved photoemission study of the iron pnictide superconductor KFe2As2 with  Tc~  4 K. Most of the observed Fermi surfaces show almost two-dimensional shapes, while one of the quasi-particle bands near the Fermi level has a strong dispersion along the kz direction, consistent with the result of a band-structure calculation. However, hole Fermi surfaces α and ζ are smaller than those predicted by the calculation while other Fermi surfaces are larger. These observations are consistent with the result of a de Haas–van Alphen study and a theoretical prediction on inter-band scattering, possibly indicating many body effects on the electronic structure.