论文标题
在无限层镍中，异常依赖孔掺杂的电子不稳定性和电子 - 音波耦合
Unusual Hole-doping-dependent Electronic Instability and Electron-Phonon Coupling in Infinite-layer Nickelates
论文作者
论文摘要
在铜矿中掺杂孔掺杂下的超导性和电荷密度波（CDW）之间的相互作用是冷凝物理物理学的中心现象之一。最近，在cacuo $ _2 $ _2 $ - 镍镍rnio $ _2 $（r = la，nd）中也观察到CDW，但与丘比特的行为相比，与之相比表现出根本不同的兴奋剂兴奋剂行为，从而提出了一个具有挑战性的问题。在本文中，我们建议分别由Ni 3dx2-Y2和R 5DZ2贡献电子不稳定性（EI）和矩依赖的电子偶联（MEPC），可能是RNIO $ _2 $中CDW形成的可能原因。没有孔掺杂，范·霍夫（Van Hove）奇异性（VHS）在rnio $ _2 $中存在的独特特征（VHS）引起的强烈的费米表面嵌套（FSN），但在cacuo $ _2 $中不存在，而在cacuo $ _2 $中，EI和MEPC的不寻常的温度不寻常的功能可能会导致较高的温度cdws in rnio $ ______________________________2 $。在孔掺杂下，通过VHS的偏移和R 5DZ2的职业减少了Ni 3Dx2-Y2的FSN，分别削弱了RNIO $ _2 $中的EI和MEPC，从而抑制了CDW的形成。我们的理论不仅为一些令人困惑的实验观察提供了可能的解释，而且还为镍和酸酯中的依赖孔掺杂的EI和MEPC建立了统一的理解。
The interplay between superconductivity and charge density waves (CDWs) under hole doping in cuprates is one of the central phenomena in condensed matter physics. Recently, CDWs are also observed in CaCuO$_2$-analogous nickelates RNiO$_2$ (R = La, Nd) but exhibit fundamentally different hole-doping-dependent behaviors compared to that in cuprates, raising a challenging question on its origin. In this article, we propose that electronic instability (EI) and moment-dependent electron-phonon coupling (MEPC), mainly contributed by Ni 3dx2-y2 and R 5dz2, respectively, may be the possible reasons for CDW formation in RNiO$_2$. Without hole doping, a strong Fermi surface nesting (FSN) induced by the unique feature of van Hove singularity (VHS) across Fermi level exists in RNiO$_2$ but not in CaCuO$_2$, and the unusual temperature-insensitive feature of EI and MEPC could result in rather high temperature CDWs in RNiO$_2$. Under hole doping, the reduced FSN of Ni 3dx2-y2 by the shift of VHS and decreased occupation of R 5dz2 largely weaken EI and MEPC in RNiO$_2$, respectively, suppressing the CDW formation. Our theory not only offers possible explanations to some puzzling experimental observations, but also establishes a unified understanding on the hole-doping-dependent EI and MEPC in nickelates and cuprates.
