Lifshitz transition and frustration of magnetic moments in infinite-layer NdNiO2 upon hole doping
Lifshitz transition and frustration of magnetic moments in infinite-layer NdNiO2 upon hole doping
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DOI：
10.1103/physrevb.101.241108
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发表时间：
2020-03
影响因子：
3.7
通讯作者：
I. Leonov;I. Leonov;S. Skornyakov;S. Skornyakov;S. Savrasov
中科院分区：
文献类型：
--
作者：
I. Leonov;I. Leonov;S. Skornyakov;S. Skornyakov;S. Savrasov
受最近在具有Sr含量$x\simeq0.2 $的无限层（Sr，Nd）NiO $_2 $膜中超导电性的发现的启发[Li等人，Nature（伦敦）\textbf{572}，624（2019）]，我们使用相关电子的动态平均场理论和能带结构方法相结合，研究了电子相关性和Sr掺杂对（Nd，Sr）NiO 2 $中电子结构、费米表面拓扑和磁相关性的影响。我们的结果揭示了Ni 3d带的轨道选择重整化，d x^2-y^2}$和d 3z^2-r^2}$轨道的m */m\sim分别为3$和1.3，表明Ni 3d态的轨道依赖局域化.我们发现，空穴掺杂后（Nd，Sr）NiO_（2+）发生费米面的Lifshitz转变，并伴随着磁关联从三维Neel_G_（111）型转变为准二维C_（110）型.结果表明，（Nd，Sr）NiO_2 $中的磁相互作用表现出一种意想不到的挫挫，它抑制了磁有序，暗示了面内自旋涨落对解释其超导电性的重要性.我们的研究结果表明，挫折是最大的Sr掺杂$x \simeq 0.1$-0.2，这是与实验观察到的掺杂值Sr $x \simeq 0.2$的超导（Nd，Sr）NiO $2 $。
Motivated by the recent discovery of superconductivity in the infinite-layer (Sr,Nd)NiO$_2$ films with Sr content $x \simeq0.2$ [Li et al., Nature (London) \textbf{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)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 $m$*/$m\sim 3$ and 1.3 for the $d_{x^2-y^2}$ and $d_{3z^2-r^2}$ orbitals, respectively, that suggests orbital-dependent localization of the Ni $3d$ states. We find that upon hole doping (Nd,Sr)NiO$_2$ undergoes a Lifshitz transition of the Fermi surface which is accompanied by a change of magnetic correlations from the three-dimensional (3D) Neel $G$-type (111) to the quasi-2D $C$-type (110). We show that magnetic interactions in (Nd,Sr)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 $x \simeq 0.1$--0.2, which is in agreement with an experimentally observed doping value Sr $x \simeq 0.2$ of superconducting (Nd,Sr)NiO$_2$.