论文标题
$ \ textit {ab intib} $基于无限层镍的GW近似
$\textit{Ab initio}$ downfolding based on the GW approximation for infinite-layer nickelates
论文作者
论文摘要
我们根据GW近似（GWA）获得的频带结构得出了无限层镍盐的有效三轨模型，在其中我们考虑ni 3 $ d_ {x^2-y^2} $和O 2 $ p $ p $ orbitals构成$σ$ bond。在GWA中，对局部密度近似（LDA）的自我能量校正增加了Ni $ 3D_ {X^2-Y^2} $和O $ 2P $之间的能量差，从而减少了3 $ d_ {x^2-y^2} $ ORBITALS的抗Bantwidth。 Fermi级别周围的Ni $ 3D_ {X^2-Y^2} $的隔离会抑制筛选效果。结果，相关效应比基于LDA的折叠折叠的模型中的相关效应更为重要。此外，在基于GWA的有效模型中，Mott-Hubbard类型的字符增强了，因为与相互作用参数的增加相比，电荷转移能量的增加更快。
We derive an effective three-orbital model for the infinite-layer nickelates based on the band structure obtained by the GW approximation (GWA), where we consider the Ni 3$d_{x^2-y^2}$ and O 2$p$ orbitals forming the $σ$-bond. In the GWA, the self-energy correction to the local density approximation (LDA) increases the energy difference between Ni $3d_{x^2-y^2}$ and O $2p$, which reduces the bandwidth of the antibonding 3$d_{x^2-y^2}$ orbitals. The isolation of the Ni $3d_{x^2-y^2}$ around the Fermi level suppresses the screening effect. As a result, the correlation effect becomes more significant than that in the model constructed by the LDA-based downfolding. Furthermore, the Mott-Hubbard type character is enhanced in the GWA-based effective model, because the charge-transfer energy increases more rapidly compared to the increase in the interaction parameters.
