Quasiparticle self-consistent GW study of LaNiO3 and LaNiO3/LaAlO3 superlattice

Using quasiparticle self-consistent GW calculations, we examined the electronic structure of LaNiO3 and the LaNiO3/LaAlO3 superlattice. The effects of electron correlation in Ni-d bands were reasonably well described without any ad hoc parameter and without the ambiguity related to the double-counting and downfolding issues. The effective mass is about 30% enhanced compared to the GGA result. One band feature, which is believed to be essential for the cupratelike superconductivity, is not realized and the central Fermi surface pocket does not disappear. Our result is consistent with a recent dynamical mean-field calculation based on the d-p model and in contrast to the result from a d-band-only model.