Determination of the orbital moment and crystal field splitting in LaTiO${}_3$

Abstract

Utilizing a sum-rule in a spin-resolved photoelectron spectroscopic experiment with circularly polarized light, we show that the orbital moment in LaTiO${}_3$ is strongly reduced both below and above the Néel temperature. Using Ti $L_{2,3}$ x-ray absorption spectroscopy as a local probe, we found that the crystal field splitting in the $t_{2g}$ subshell is about 0.12-0.30 eV. This large splitting does not facilitate the formation of an orbital liquid.