Is Nozieres Exhaustion Principle playing a role in the physics of the nickelate superconductors ?

We perform self-consistent embedded dynamical mean field theory (eDMFT) calculations on LaNiO₂ and NdNiO₂ across a wide range of temperature (T) and correlation (U). We find evidence that Nozieres Exhaustion Principle (NEP) plays a role in the low-T physics of the nickelates. Below a characteristic T, we find the system to be Fermi liquid (FL) like, where the scattering rate goes to zero as T², and the Ni-d moments are rapidly getting screened by the conduction electrons. Below the FL temperature, our T-dependent calculation of hybridization and density of states (DOS) show pronounced dip in hybridization below the Fermi level, at the location of the peak in the Ni-d DOS. We suggest that the dip in hybridization arises from insufficient number of conduction electrons needed to fully screen the Ni-d moments, i.e., in essence NEP. This effect pushes down the coherence temperature that signifies full screening. We speculate that superconductivity may be facilitated once there are extra carriers upon doping, thereby increasing the coherence temperature. We also discuss the broader picture that emerges from our calculations as a function of temperature and correlation.