Lifshitz transition and frustration of magnetic moments in infinite-layer <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>NdNiO</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:math> upon hole doping

Abstract

Motivated by the recent discovery of superconductivity in infinite-layer $(\text{Sr},\mathrm{Nd}){\mathrm{NiO}}_{2}$ films with Sr content $x\ensuremath{\simeq}0.2$ [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 $(\text{Nd},\mathrm{Sr}){\mathrm{NiO}}_{2}$ 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 ${m}^{*}/m\ensuremath{\sim}3$ and 1.3 for the ${d}_{{x}^{2}\ensuremath{-}{y}^{2}}$ and ${d}_{3{z}^{2}\ensuremath{-}{r}^{2}}$ orbitals, respectively, that suggests orbital-dependent localization of the Ni $3d$ states. We find that upon hole doping, $(\text{Nd},\mathrm{Sr}){\mathrm{NiO}}_{2}$ undergoes a Lifshitz transition of the Fermi surface which is accompanied by a change of magnetic correlations from three-dimensional (3D) N\'eel $G$-type (111) to quasi-2D $C$-type (110). We show that magnetic interactions in $(\text{Nd},\mathrm{Sr}){\mathrm{NiO}}_{2}$ 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 $x\ensuremath{\simeq}0.1--0.2$, which is in agreement with an experimentally observed doping value Sr $x\ensuremath{\simeq}0.2$ of superconducting $(\text{Nd},\mathrm{Sr}){\mathrm{NiO}}_{2}$.

Topics & Concepts