Origin of the d-orbital heavy fermion. Observation of Kondo resonance peak by laser excited photoemission spectroscopy

We have performed a laser excited high-resolution photoemission spectroscopy on a 3d-electron heavy-Fermion-like material LiV2O4 and observed a sharp peak structure in the density of states at ∼4 MeV above the Fermi level. Energy scale and temperature dependence of the peak structure are quite similar to the Kondo resonance peak observed in conventional f-electron heavy Fermion compounds. It is indicative of the Kondo effect as the origin of the mass renormalization in this system. (author)