"Revisiting the Yb electronic structure with low-energy photoemission spectroscopy"

Low-energy photoemission spectroscopy in the photon energy range between 5.5 and 21 eV is used to investigate the valence electronic structure of Yb polycrystalline films. With the lowering of the photon energy below 11 eV, additional spectral features, nearly absent at higher photon energy, become predominant, in particular a peak located right at the Fermi level. With the help of an ab initio theoretical calculation, we interpret the peak as due to the joint influence of filled and empty densities of states, identifying a p-band contribution close to the Fermi level, whose intensity is strongly enhanced at certain photon energies corresponding to modulation of the empty d band.