Doping-induced magnetic two-dimensionality and many-body electronic structure of superconducting infinite-layer nickelate

To understand the superconductivity recently discovered in Nd_1-xSr_xNiO₂, 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 indicates the localized character of its spin moment. We also analyzed the low-frequency behavior of self-energy and resulting correlation strength. Remarkable new finding is that magnetic interactions in this material become two-dimensional by hole doping. While the undoped NdNiO₂ has the sizable out-of-plane interaction, hole dopings strongly suppress it. This two-dimensionality is maximized at the hole concentration of δ ≈ 0.25. Further analysis as well as the implications of our new findings are presented.