Charge density wave ordering in NdNiO2: effects of multiorbital nonlocal correlations

Abstract

In this work, we investigate collective electronic fluctuations and, in particular, the possibility of the charge density wave ordering in an infinite-layer NdNiO2. We perform advanced many-body calculations for the ab-initio three-orbital model by taking into account local correlation effects, nonlocal charge and magnetic fluctuations, and the electron-phonon coupling. We find that in the considered material, electronic correlations are strongly orbital- and momentum-dependent. Notably, the charge density wave and magnetic instabilities originate from distinct orbitals. In particular, we show that the correlation effects lead to the momentum-dependent hybridization between different orbitals, resulting in the splitting and shifting of the flat part of the Ni-$${d}_{{z}^{2}}$$ d z 2 band. This strong renormalization of the electronic spectral function drives the charge density wave instability that is related to the intraband Ni-$${d}_{{z}^{2}}$$ d z 2 correlations. Instead, the magnetic instability stems from the Ni-$${d}_{{x}^{2}-{y}^{2}}$$ d x 2 − y 2 orbital, which remains half-filled through the redistribution of the electronic density between different bands even upon hole doping. Consequently, the strength of the magnetic fluctuations remains nearly unchanged for the considered doping levels. We argue that this renormalization is not inherent to the stoichiometric case but can be induced by hole doping.