Induced magnetic two-dimensionality by hole doping in the superconducting infinite-layer nickelate Nd${}_{1-x}$Sr${}_x$NiO${}_2$

Abstract

To understand the superconductivity recently discovered in Nd${}_{0.8}$Sr${}_{0.2}$NiO${}_2$, we carried out LDA+DMFT (local density approximation plus dynamical mean-field theory) and magnetic force response calculations. The on-site correlation in Ni-$3d$ orbitals causes notable changes in the electronic structure. The calculated temperature-dependent susceptibility exhibits the Curie-Weiss behavior, indicating the localized character of its moment. From the low-frequency behavior of self-energy, we conclude that the undoped phase of this nickelate is Fermi-liquid-like contrary to cuprates. Interestingly, the estimated correlation strength by means of the inverse of quasiparticle weight is found to increase and then decrease as a function of hole concentration, forming a dome-like shape. Another finding is that magnetic interactions in this material become two-dimensional by hole doping. While the undoped NdNiO${}_2$ has the sizable out-of-plane interaction, hole dopings strongly suppress it. This two-dimensionality is maximized at the hole concentration $\delta \approx 0.25$. Further analysis as well as the implications of our findings are presented.