Li Zhenglu, Louie Steven G
Department of Physics, <a href="https://ror.org/01an7q238">University of California at Berkeley</a>, Berkeley, California 94720, USA.
Materials Sciences Division, <a href="https://ror.org/02jbv0t02">Lawrence Berkeley National Laboratory</a>, Berkeley, California 94720, USA.
Phys Rev Lett. 2024 Sep 20;133(12):126401. doi: 10.1103/PhysRevLett.133.126401.
We present a theoretical prediction of a phonon-mediated two-gap superconductivity in infinite-layer nickelates Nd_{1-x}Sr_{x}NiO_{2} by performing ab initio GW and GW perturbation theory calculations. Electron GW self-energy effects significantly alter the characters of the two-band Fermi surface and enhance the electron-phonon coupling, compared with results based on density functional theory. Solutions of the fully k-dependent anisotropic Eliashberg equations yield two dominant s-wave superconducting gaps-a large gap on a band of rare-earth Nd d and interstitial orbital characters and a small gap on a band of transition-metal Ni d character. Increasing hole doping induces a non-rigid-band response in the electronic structure, leading to a rapid drop of the superconducting T_{c} in the overdoped regime in agreement with experiments.
通过进行从头算GW和GW微扰理论计算，我们给出了无限层镍酸盐Nd_{1-x}Sr_{x}NiO_{2}中声子介导的双能隙超导性的理论预测。与基于密度泛函理论的结果相比，电子GW自能效应显著改变了双带费米面的特征，并增强了电子-声子耦合。完全依赖于k的各向异性Eliashberg方程的解产生了两个主要的s波超导能隙——一个在具有稀土Nd d和间隙轨道特征的能带中的大能隙，以及一个在具有过渡金属Ni d特征的能带中的小能隙。空穴掺杂的增加在电子结构中引起非刚性带响应，导致在过掺杂区域中超导转变温度T_{c}迅速下降，这与实验结果一致。
