Orbital polarization in LiVO_2 and NaTiO_2

TL;DR

This study investigates the orbital polarization and ordering in LiVO_2 and NaTiO_2, revealing different behaviors due to crystal symmetry and Coulomb interactions, with implications for understanding their electronic properties.

Contribution

It provides a comparative band structure analysis of LiVO_2 and NaTiO_2, highlighting the effects of symmetry and Coulomb interactions on orbital degeneracy and ordering.

Findings

NaTiO_2 exhibits lifted t_{2g} degeneracy due to trigonal symmetry and Coulomb interactions.

LiVO_2 maintains orbital degeneracy but shows orbital ordering linked to lattice trimerization.

Distinct orbital behaviors are explained by structural and electronic differences.

Abstract

We present a band structure study of orbital polarization and ordering in the two-dimensional triangular lattice transition metal compounds LiVO_2 and NaTiO_2. It is found that while in NaTiO_2 the degeneracy of t_{2g} orbitals is lifted due to the trigonal symmetry of the crystal and the strong on cite Coulomb interaction, in LiVO_2 orbital degeneracy remains and orbital ordering corresponding to the trimerization of the two-dimensional lattice develops.