Motivated by recent experiments, we use the +U extension of the generalized gradient approximation to density functional theory to study superlattices composed of alternating layers of LaNiO3 and LaMnO3. For comparison we also study a rocksalt ((111) double perovskite) structure and bulk LaNiO3 and LaMnO3. A Wannier function analysis indicates that band parameters are transferable from bulk to superlattice situations with the exception of the transition metal d-level energy, which has a contribution from the change in d-shell occupancy. The charge transfer from Mn to Ni is found to be moderate in the superlattice, indicating metallic behavior, in contrast to the insulating behavior found in recent experiments, while the rocksalt structure is found to be insulating with a large Mn-Ni charge transfer. We suggest a high density of cation antisite defects may account for the insulating behavior experimentally observed in short-period superlattices.
@article{arxiv.1704.08886,
title = {Charge transfer and metallicity in LaNiO$_3$/LaMnO$_3$ superlattices},
author = {Alejandro Lopez-Bezanilla and Louis-François Arsenault and Anand Bhattacharya and Peter B. Littlewood and Andrew J. Millis},
journal= {arXiv preprint arXiv:1704.08886},
year = {2019}
}