TY - JOUR
T1 - Electron correlation in the FeSe superconductor studied by bulk-sensitive photoemission spectroscopy
AU - Yamasaki, A.
AU - Matsui, Y.
AU - Imada, S.
AU - Takase, K.
AU - Azuma, H.
AU - Muro, T.
AU - Kato, Y.
AU - Higashiya, A.
AU - Sekiyama, A.
AU - Suga, S.
AU - Yabashi, M.
AU - Tamasaku, K.
AU - Ishikawa, T.
AU - Terashima, K.
AU - Kobori, H.
AU - Sugimura, A.
AU - Umeyama, N.
AU - Sato, H.
AU - Hara, Y.
AU - Miyagawa, N.
AU - Ikeda, S. I.
PY - 2010/11/8
Y1 - 2010/11/8
N2 - We have investigated the electronic structures of recently discovered superconductor FeSe by soft-x-ray and hard-x-ray photoemission spectroscopy with high-bulk sensitivity. The large Fe3d spectral weight is located in the vicinity of the Fermi level (EF), which is demonstrated to be a coherent quasiparticle peak. Compared with the results of the band-structure calculation with local-density approximation, Fe3d band narrowing and the energy shift of the band toward EF are found, suggesting an importance of the electron correlation effect in FeSe. The self-energy correction provides the larger mass enhancement value (Z-1 ≃3.6) than in Fe-As superconductors and enables us to separate an incoherent part from the spectrum. These features are quite consistent with the results of recent dynamical mean-field calculations, in which the incoherent part is attributed to the lower Hubbard band.
AB - We have investigated the electronic structures of recently discovered superconductor FeSe by soft-x-ray and hard-x-ray photoemission spectroscopy with high-bulk sensitivity. The large Fe3d spectral weight is located in the vicinity of the Fermi level (EF), which is demonstrated to be a coherent quasiparticle peak. Compared with the results of the band-structure calculation with local-density approximation, Fe3d band narrowing and the energy shift of the band toward EF are found, suggesting an importance of the electron correlation effect in FeSe. The self-energy correction provides the larger mass enhancement value (Z-1 ≃3.6) than in Fe-As superconductors and enables us to separate an incoherent part from the spectrum. These features are quite consistent with the results of recent dynamical mean-field calculations, in which the incoherent part is attributed to the lower Hubbard band.
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U2 - 10.1103/PhysRevB.82.184511
DO - 10.1103/PhysRevB.82.184511
M3 - Article
AN - SCOPUS:78649688389
SN - 1098-0121
VL - 82
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 18
M1 - 184511
ER -