Effect of lattice strain on the electronic structure and magnetic correlations in infinite-layer (Nd,Sr)NiO2

We present a theoretical study of the effect electron-electron interactions and Sr doping on electronic structure infinite-layer (Nd,Sr)NiO$_2$ using density functional+dynamical mean-field theory approach. In particular, we explore impact epitaxial compressive strain that experience films properties, magnetic correlations, exchange couplings. Our results reveal crucial importance orbital-dependent correlation effects in Ni $3d$ shell Sr-doped NdNiO$_2$. Upon with Sr, it undergoes Lifshitz transition which is accompanied by reconstruction correlations: For $x<0.2$ adopts N\'eel $(111)$ antiferromagnetic (AFM) order, while for $x>0.2$ $C$-type $(110)$ AFM sets unstrained (Nd,Sr)NiO$_2$, highly frustrated region at $x \simeq 0.2$, all within DFT+DMFT $T=290$ K. $x=0$ suggest NdNiO$_2$ appears verge Mott-Hubbard transition, providing plausible explanation experimentally observed weakly insulating behavior $x<0.1$. observe makes change band character from electron- to hole-like $x$, agreement recent experiments. couplings demonstrate an unanticipated frustration moments, suppresses order near $x=0.2$. find maximal 0.1-0.2$ nearly corresponds value. conclude in-plane adjusts bandwidth $x^2-y^2$ band, i.e., controls electron correlations orbitals. The properties anomalous sensitivity upon crystal parameters.