论文标题
无限镍镍的哈伯德子带和超导性
Hubbard subbands and superconductivity in the infinite-layer nickelate
论文作者
论文摘要
无限层镍盐的有效二维两波段模型由从$ d_ {x^2-y^2} $和$ s $的频段组成。我们调查是否可以将其映射到单频段哈伯德模型和哈伯德频段的填充上。我们发现，根据电子相关性的强度和流动的$ s $ band的填充，从相同的两轨模型中出现了一波段物理和伴有伴有伴随的晶体。接下来，我们通过更改筛选来研究一粒子激发。首先，对于较弱的筛选，强相关性将电子从$ S $带中推出，以使未扎的镍类似于铜酸盐。其次，为了强筛选$ s $和$ d_ {x^2-y^2} $ bands均部分填充和弱夫妇。特别是在后一种状态映射到一个波段模型的情况下，在哈伯德子带之间可显着转移光谱重量。最后，我们指出，超导阶段可能具有$ d $ - 波或$ s $ - 波浪对称性。
An effective two-dimensional two-band model for infinite-layer nickelates consists of bands obtained from $d_{x^2-y^2}$ and $s$--like orbitals. We investigate whether it could be mapped onto a single-band Hubbard model and the filling of Hubbard bands. We find that both one-band physics and a Kondo-lattice regime emerge from the same two-orbital model, depending on the strength of electronic correlations and the filling of the itinerant $s$-band. Next we investigate one-particle excitations by changing the screening. First, for weak screening the strong correlations push electrons out of the $s$-band so that the undoped nickelate is similar to a cuprate. Second, for strong screening the $s$ and $d_{x^2-y^2}$ bands are both partly filled and weakly couple. Particularly in this latter regime mapping to a one-band model gives significant spectral weight transfer between the Hubbard subbands. Finally we point out that the superconducting phases may have either $d$-wave or $s$-wave symmetry.
