论文标题
外延应变对无限层（ND，SR）Nio $ _2 $中电子结构和磁相关性的影响
Effect of epitaxial strain on the electronic structure and magnetic correlations in infinite-layer (Nd,Sr)NiO$_2$
论文作者
论文摘要
我们介绍了使用密度+动力学均值场理论方法，对电子 - 电子相互作用和SR掺杂对无限层（ND，SR）Nio $ _2 $的电子结构的影响的影响。特别是，我们探讨了体验（ND，SR）Nio $ _2 $胶片对电子特性，磁相关和交换耦合的影响。我们的结果揭示了依赖轨道依赖性相关效应的至关重要性在ni $ 3d $ shell of Sr-doped ndnio $ _2 $中。与SR兴奋剂后，它发生了Lifshitz的过渡，并伴随着磁相关的重建：对于SR $ x <0.2 $（nd，sr）NIO $ _2 $采用Néel$（111）$ anteromagnetic（111）$ antifermagnetic（AFM），而$ x> 0.2 $ $ x $ $ c $ -c $ -cy-cy sets in $ cy sets sets sets setss sets sets setss setss setss setss setss setss setss setssss setss setss setss setss $ typre（110）。 (Nd,Sr)NiO$_2$, with a highly frustrated region at $x \simeq 0.2$, all within DFT+DMFT at $T=290$ K. Our results for the Néel AFM at Sr $x=0$ suggest that AFM NdNiO$_2$ appears at the verge of a Mott-Hubbard transition, providing a plausible explanation for the experimentally observed weakly ndnio $ _2 $的绝缘行为，$ x $ x <0.1 $。我们观察到，LifShitz的过渡将带有sr $ x $的频带结构特征从电子方式变为孔，与最近的实验一致。我们的磁性耦合结果表明，Ni $ 3D $磁矩的意外挫败感，这抑制了SR $ x = 0.2 $的磁性顺序。我们发现，挫败感的效果对于Sr掺杂$ x \ simeq 0.1-0.2 $的影响几乎与实验观察到的掺杂值相对应。我们得出的结论是，平面应变调整了Ni $ X^2-Y^2 $频段的带宽，即控制Ni $ x^2-y^2 $ orbitals中电子相关性的效果。 （ND，SR）NiO $ _2 $的电子特性在变化晶体结构参数时显示出异常的灵敏度。
We present a theoretical study of the effect of electron-electron interactions and Sr doping on the electronic structure of infinite-layer (Nd,Sr)NiO$_2$ using the density functional+dynamical mean-field theory approach. In particular, we explore the impact of epitaxial compressive strain that experience (Nd,Sr)NiO$_2$ films on the electronic properties, magnetic correlations, and exchange couplings. Our results reveal the crucial importance of orbital-dependent correlation effects in the Ni $3d$ shell of Sr-doped NdNiO$_2$. Upon doping with Sr, it undergoes a Lifshitz transition which is accompanied by a reconstruction of magnetic correlations: For Sr $x<0.2$ (Nd,Sr)NiO$_2$ adopts the Néel $(111)$ antiferromagnetic (AFM) order, while for $x>0.2$ the $C$-type $(110)$ AFM sets in the unstrained (Nd,Sr)NiO$_2$, with a highly frustrated region at $x \simeq 0.2$, all within DFT+DMFT at $T=290$ K. Our results for the Néel AFM at Sr $x=0$ suggest that AFM NdNiO$_2$ appears at the verge of a Mott-Hubbard transition, providing a plausible explanation for the experimentally observed weakly insulating behavior of NdNiO$_2$ for Sr $x<0.1$. We observe that the Lifshitz transition makes a change of the band structure character from electron- to hole-like with Sr $x$, in agreement with recent experiments. Our results for magnetic couplings demonstrate an unanticipated frustration of the Ni $3d$ magnetic moments, which suppresses magnetic order near Sr $x=0.2$. We find that the effect of frustration is maximal for Sr doping $x \simeq 0.1-0.2$ that nearly corresponds to the experimentally observed doping value. We conclude that the in-plane strain adjusts a bandwidth of the Ni $x^2-y^2$ band, i.e., controls the effect of electron correlations in the Ni $x^2-y^2$ orbitals. The electronic properties of (Nd,Sr)NiO$_2$ reveal an anomalous sensitivity upon a change of the crystal structure parameters.
