1110.0386 (Alaska Subedi)

First-principles study of the electronic structure and magnetism of
CaIrO$_3$    [PDF]

Alaska Subedi

I study the electronic structure and magnetism of postperovskite CaIrO$_3$
using first-principles calculations. The density functional calculations within
the local density approximation without the combined effect of spin-orbit
coupling and on-site Coulomb repulsion show the system to be metallic, which is
in disagreement with the recent experimental evidences that show CaIrO$_3$ to
be an antiferromagnetic Mott insulator in the $J_\textrm{eff}$ = 1/2 state.
However, when spin-orbit coupling is taken into account, the Ir $t_{2g}$ bands
split into fully filled $J_\textrm{eff}$ = 3/2 bands and half-filled
$J_\textrm{eff}$ = 1/2 bands. I find that spin-orbit coupling along with a
modest on-site Coulomb repulsion opens a gap leading to a Mott insulating
state. The ordering is antiferromagnetic along the c axis with total moments
aligned antiparallel along the c axis and canted along the b axis.

View original: http://arxiv.org/abs/1110.0386