Formation of a two-dimensional single-component correlated electron system and band engineering in the nickelate superconductor NdNiO2

Motivated by the discovery of the nickelate superconductor Nd0.8Sr0.2NiO₂, the authors construct an effective low-energy Hamiltonian for the parent compound NdNiO₂, which is found to be strongly correlated. While high-Tc superconductivity emerges near the Mott-insulating phase in the cuprates, NdNiO₂ is not a Mott insulator, because the 3d x²-y² band of nickel is self-doped. The authors propose a route for the design of novel nickelates where self-doping is suppressed. If synthesized, such nickelates would provide a playground for the exploration of high-Tc superconductivity.