Influence of f Electrons on the Electronic Band Structure of Rare-Earth Nickelates

Recently, superconductivity was discovered in the infinite layer of hole-doped nickelates NdNiO2. Contrary to this, superconductivity in LaNiO2 is still under debate. This indicates the crucial role played by the f electrons on the electronic structure and the pairing mechanism of infinite-layer nickelates. Here, we discuss the role of the electron correlations in the f electron states and their influence on the electronic structure. We show that the lattice parameters are in good agreement with the experimental values, independent of the chosen parameters within the DFT+U approach. Increasing Coulomb interaction U tends to shift the f states away from the Fermi level. Surprisingly, independently of the position of f states with respect to the Fermi energy, these states play an important role in the electronic band structure, which can be reflected in the modification of the NdNiO2 effective models.

Automated summary

Recently, superconductivity has been discovered in the infinite layer of hole-doped nickelates NdNiO2, while the superconductivity in LaNiO2 is still a subject of debate. This indicates the significant influence of f-electrons on the electronic structure and pairing mechanism of infinite-layer nickelates. The role of electron correlations in f-electron states and their impact on the electronic structure are discussed. It is found that the lattice parameters are consistent with experimental values regardless of the chosen parameters in the DFT+U approach. Increasing Coulomb interaction U shifts the f-states away from the Fermi level. Surprisingly, regardless of the position of f-states relative to the Fermi energy, these states play an important role in the electronic band structure, leading to modifications in the effective models of NdNiO2.