论文标题
无期的无限层镍超导体中电荷顺序的比较研究
Comparative study of charge order in undoped infinite-layer nickelate superconductors
论文作者
论文摘要
为了了解无限镍镍超导体的父元化合物中观察到的电荷顺序的显微镜机制，我们考虑了一个最小的三腿模型，该模型由ni $ 3d_ $ 3d_ {x^2-y^2} $ the Profe the Pref the Parre Electron the Parre-eartons of Pree Electron the Profer-eartss s ni $ 3d_ $ 3d_ $ 3D_ {通过高度准确的密度矩阵重新归一化组的计算，当调整化学电势差以使Hubbard梯子以$ 1/3 $ hole掺杂的速度使Hubbard梯子时，我们找到了一个远程充电顺序，在模型基础状态下，售价为3美元，而自旋激发则具有较小的能量差距。此外，电子配对相关性具有准长范围的行为，即使在半填充时也表明超导性的不稳定。作为比较，将相同的方法应用于具有$ 1/3 $ hole掺杂的纯二腿哈伯德模型，其中周期-3充电顺序为准长范围。它们之间的差异表明，三足梯子的自由电子链起着电荷储层的作用，并增强了无凝结的无限层镍盐中的电荷顺序。
To understand the microscopic mechanism of the charge order observed in the parent compound of the infinite-layer nickelate superconductors, we consider a minimal three-legged model consisting of a two-legged Hubbard ladder for the Ni $3d_{x^2-y^2}$ electrons and a free conduction electron chain from the rare-earths. With highly accurate density matrix renormalization group calculations, when the chemical potential difference is adjusted to make the Hubbard ladder with $1/3$ hole doping, we find a long-range charge order with period $3$ in the ground state of the model, while the spin excitation has a small energy gap. Moreover, the electron pair-pair correlation has a quasi-long-range behavior, indicating an instability of superconductivity even at half-filling. As a comparison, the same method is applied to a pure two-legged Hubbard model with $1/3$ hole doping in which the period-3 charge order is a quasi-long range one. The difference between them demonstrates that the free electron chain of the three-legged ladder plays the role of a charge reservoir and enhances the charge order in the undoped infinite-layer nickelates.
