Electronic structure of ThRuSi studied by angle-resolved photoelectron spectroscopy; Elucidating the contribution of U 5 states in URuSi

Fujimori, Shinichi   ; Kobata, Masaaki  ; Takeda, Yukiharu   ; Okane, Tetsuo  ; Saito, Yuji  ; Fujimori, Atsushi; Yamagami, Hiroshi; Matsumoto, Yuji*; Yamamoto, Etsuji  ; Tateiwa, Naoyuki   ; Haga, Yoshinori   

The Fermi surface and band structure of have been studied by angle resolved photoelectron spectroscopy (ARPES) with the incident photon energies of = 665-735 eV. Detailed band structure and the three-dimensional shape of the Fermi surface were derived experimentally, and they are quantitatively explained by the band-structure calculation based on the density functional approximation. Comparison of the experimental ARPES spectra of with those of shows that they have considerably different spectral profiles particularly in the energy range of - 1 eV. Some energy bands with their energy dispersions of about 1 eV observed in are missing in the ARPES spectra of measured along the same high symmetry line of Brillouin zone, suggesting that U 5 states form these bands in . The relationship between the ARPES spectra of and is very different from the case between and where their intrinsic difference is limited only in the very vicinity of the Fermi energy. The present result argues that the U 5 electrons in have strong hybridization with ligand states, and essentially have an itinerant character.