Lifshitz transition and frustration of magnetic moments in infinite-layer NdNiO2 upon hole doping

Motivated by the recent discovery of superconductivity in infinite-layer (Sr, Nd)NiO2 films with Sr content x similar or equal to 0.2 [D. Li et al., Nature (London) 572, 624 (2019)], we examine the effects of electron correlations and Sr doping on the electronic structure, Fermi-surface topology, and magnetic correlations in (Nd, Sr)NiO2 using a combination of dynamical mean-field theory of correlated electrons and band-structure methods. Our results reveal a remarkable orbital-selective renormalization of the Ni 3d bands, with m*/m similar to 3 and 1.3 for the d(x2-y2) and d(z2-r2) orbitals, respectively, that suggests orbital-dependent localization of the Ni 3d states. We find that upon hole doping, (Nd, Sr)NiO2 undergoes a Lifshitz transition of the Fermi surface which is accompanied by a change of magnetic correlations from three-dimensional (3D) Neel G-type (111) to quasi-2D C-type (110). We show that magnetic interactions in (Nd, Sr)NiO2 demonstrate an unanticipated frustration, which suppresses magnetic order, implying the importance of in-plane spin fluctuations to explain its superconductivity. Our results suggest that frustration is maximal for Sr doping x similar or equal to 0.1-0.2, which is in agreement with an experimentally observed doping value Sr x similar or equal to 0.2 of superconducting (Nd, Sr)NiO2.