Ambipolar doping-induced surface in-gap state on Mott-insulating Ca${}_2$RuO${}_4$

M. Horio, T. Wada, V. Granata +4

We report an x-ray photoemission spectroscopy study of Ca${}_2$RuO${}_4$ surface-dosed with Cs alkali atoms and C${}_{60}$ molecules. Due to its small ionization energy (large electron a…