Condensed Matter Physics; Electronic, Optical and Magnetic Materials
en
Abstract:
Many-body calculations for multi-orbital systems at present typically employ Slater or Kanamori interactions
which implicitly assume a full rotational invariance of the orbitals, whereas the real crystal has a lower symmetry.
In cubic symmetry, the low-energy t2g orbitals have an on-site Kanamori interaction, albeit without the constraint
U = U
+ 2J implied by spherical symmetry (U is the intra-orbital interaction, U
is the interorbital interaction,
J is Hund's exchange). Using maximally localizedWannier functions we show that deviations from the standard,
spherically symmetric interactions are indeed significant for 5d orbitals (∼25% for BaOsO3; ∼12% if screening
is included) but are less important for 3d orbitals (∼6% for SrVO3; ∼1% if screened).