Quasiparticle self-consistent GW band structure of CrN

Abstract

The band structures of CrN are calculated using the quasiparticle self-consistent $GW$ approach in both the low-temperature antiferromagnetic (AFM) [$110{\mathrm{]}}_{2}\phantom{\rule{4pt}{0ex}}Pmna$ orthorhombic phase and in a hypothetical ferromagnetic phase representing the paramagnetic cubic state in a saturating magnetic field. A gap of about 1 eV is found in the AFM state, while the ferromagnetic band structure is found to be half metallic. Another hypothetical AFM-1 structure [$001{\mathrm{]}}_{1}$ is also considered and gives a smaller band gap. The orbital nature of the bands is studied and reveals a gap between Cr-$d$ states, indicating a strongly correlated behavior. Optical dielectric functions are calculated from the interband transitions and compared to experimental data.