Hubbard band or oxygen vacancy states in the correlated electron metal SrVO$_3$?

• Main Authors: Backes, S, R ödel, T. C, Fortuna, F, Frantzeskakis, E, Fèvre, P. Le, Bertran, F, Kobayashi, M, Yukawa, R, Mitsuhashi, T, Kitamura, M, Horiba, K, Kumigashira, H, Saint-Martin, R, Fouchet, A, Berini, B, Dumont, Y, Kim, A. J, Lechermann, F, Jeschke, H. O, Rozenberg, M. J, Valentí, R, Santander-Syro, A. F
• Format: Journal Article
• Language: English
• Published: 22-02-2016
• Subjects: Physics - Strongly Correlated Electrons
• DOI: 10.48550/arxiv.1602.06909

Phys. Rev. B 94, 241110 (2016) We study the effect of oxygen vacancies on the electronic structure of the
model strongly correlated metal SrVO$_3$. By means of angle-resolved
photoemission (ARPES) synchrotron experiments, we investigate the systematic
effect of the UV dose on the measured spectra. We observe the onset of a
spurious dose-dependent prominent peak at an energy range were the lower
Hubbard band has been previously reported in this compound, raising questions
on its previous interpretation. By a careful analysis of the dose dependent
effects we succeed in disentangling the contributions coming from the oxygen
vacancy states and from the lower Hubbard band. We obtain the intrinsic ARPES
spectrum for the zero-vacancy limit, where a clear signal of a lower Hubbard
band remains. We support our study by means of state-of-the-art ab initio
calculations that include correlation effects and the presence of oxygen
vacancies. Our results underscore the relevance of potential spurious states
affecting ARPES experiments in correlated metals, which are associated to the
ubiquitous oxygen vacancies as extensively reported in the context of a
two-dimensional electron gas (2DEG) at the surface of insulating $d^0$
transition metal oxides.