论文标题
稀有地球$ d $电子在无限层镍中的两间隙超导性和决定性作用
Two-gap superconductivity and decisive role of rare-earth $d$ electrons in infinite-layer nickelates
论文作者
论文摘要
我们提出了一个理论上的预测，对无限层镍镍nd $ _ {0.8} $ _ {0.2} $ _ {0.2} $ nio $ _2 $的两个nikeLates nd $ _ {0.8} $ _2 $的理论预测。与基于密度功能理论的结果相比，电子$ GW $自我能源效应显着改变了两波段费米表面的特征，并增强了电子 - 光子耦合。完全$ \ textbf {k} $ - 依赖性各向异性EliAshberg方程的解决方案产生了两个主导的$ S $ - 波超导差距 - 在稀有稀有的nd $ d $和间际轨道轨道和间质轨道字符的带上的较大差距以及在过渡 - ni $ d $ d $ d $ d $ d $ d $ d $ d $ d $ d $ d $ d $ d $ d $ d $ d $ d $ d $ d $ d $ d $ d $ d pharnity上。增加的孔掺杂会在电子结构中引起非刚性带反应，从而导致超导$ T_C $在与实验一致的超导性$ T_C $中迅速下降。
We present a theoretical prediction of a phonon-mediated two-gap superconductivity in infinite-layer nickelates Nd$_{0.8}$Sr$_{0.2}$NiO$_2$ by performing $\textit{ab initio}$ $GW$ 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 $\textbf{k}$-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.
