Title: Electronic structure of ThRu2Si2 studied by angle-resolved photoelectron spectroscopy: Elucidating the contribution of U 5f states in URu2Si2,
Abstract: The electronic structure of ThRu2Si2 was studied by angle-resolved
photoelectron spectroscopy (ARPES) with incident photon energies of hn=655-745
eV. Detailed band structure and the three-dimensional shapes of Fermi surfaces
were derived experimentally, and their characteristic features were mostly
explained by means of band structure calculations based on the density
functional theory. Comparison of the experimental ARPES spectra of ThRu2Si2
with those of URu2Si2 shows that they have considerably different spectral
profiles particularly in the energy range of 1 eV from the Fermi level,
suggesting that U 5f states are substantially hybridized in these bands. The
relationship between the ARPES spectra of URu2Si2 and ThRu2Si2 is very
different from the one between the ARPES spectra of CeRu2Si2 and LaRu2Si2,
where the intrinsic difference in their spectra is limited only in the very
vicinity of the Fermi energy. The present result suggests that the U 5f
electrons in URu2Si2 have strong hybridization with ligand states and have an
essentially itinerant character.