Self-energy on the low- to high-energy electronic structure of correlated metal SrVO₃

Abstract

The correlated electronic structure of SrVO₃ has been investigated by angle-resolved photoemission spectroscopy using in situ prepared thin films. Pronounced features of band renormalization have been observed: a sharp kink ~60  meV below the Fermi level (E_F) and a broad so-called “high-energy kink” ~0.3  eV below E_F as in the high- T_c cuprates, although SrVO₃ does not show magnetic fluctuations. We have deduced the self-energy in a wide energy range by applying the Kramers-Kronig relation to the observed spectra. The obtained self-energy clearly shows a large energy scale of ~0.7 eV, which is attributed to electron-electron interaction and gives rise to the ~0.3  eV kink in the band dispersion as well as the incoherent peak ~1.5  eV below E_F. The present analysis enables us to obtain a consistent picture for both the incoherent spectra and the band renormalization.