In contrast to the cuprates, where the proximity of antiferromagnetism (AFM) and superconductivity is well established, first indications for AFM interactions in superconducting infinite-layer nickelates were only recently obtained. Here, we explore, based on first-principles simulations, the nature of the magnetic coupling in NdNiO2 as a function of the on-site Coulomb and exchange interaction, varying the explicit hole doping and the treatment of the Nd 4f electrons. The U-J phase diagrams for undoped nickelates and cuprates indicate G-type ordering, yet show different U dependency. By either Sr hole doping or explicit treatment of the Nd 4f electrons, we find a transition to a Ni C-type AFM ground state. We trace the effect of Sr doping back to a distinct accommodation of the holes by the Ni versus Cu eg orbitals. The interaction between Nd 4f and Ni 3d states stabilizes C-type AFM order on both sublattices. Though spin-orbit interactions induce a band splitting near the Fermi energy, the bad-metal state is retained even under epitaxial strain. These results establish the distinct role of the magnetic interactions in the nickelates versus the cuprates and suggest the former as a unique platform to investigate the relation to unconventional superconductivity.
@article{arxiv.2309.12840,
title = {Nature of the magnetic coupling in infinite-layer nickelates versus cuprates},
author = {Armin Sahinovic and Benjamin Geisler and Rossitza Pentcheva},
journal= {arXiv preprint arXiv:2309.12840},
year = {2024}
}