论文标题
反铁磁波动和主要的$ d_ {xy} $ - 基于镍的超导体中的波配对对称性
Antiferromagnetic fluctuations and a dominant $d_{xy}$-wave pairing symmetry in nickelate-based superconductors
论文作者
论文摘要
在基于镍酸盐的材料中发现的超导性的最新实验研究中，我们研究了自旋相关性的温度依赖性和通过量子蒙特卡洛方法在有效的两波段哈伯德模型中的超导配对相互作用。基于从第一原理计算中提取的参数，我们的密集数值结果表明，与$ d_ {xy} $ - 波对对称配对在低温下牢固地统治了其他配对，这主要由ni 3 $ d $ orbital确定。还发现，随着现场相互作用的增加，有效的配对相互作用会增强，这表明超导性是由强电子电子相关性驱动的。即使电子相互作用可以增强$（π，π）$抗铁磁相关性，但没有证据表明在基于镍酸盐的超导体中表现出远距离抗铁磁序。此外，我们的结果提供了可能的证据，表明纯电子相关可能无法解释镍中观察到的电荷密度波状态。
Motivated by recent experimental studies on superconductivity found in nickelate-based materials, we study the temperature dependence of the spin correlation and the superconducting pairing interaction within an effective two-band Hubbard model by the quantum Monte Carlo method. Based on parameters extracted from first-principles calculations, our intensive numerical results reveal that the pairing with a $d_{xy}$-wave symmetry firmly dominates over other pairings at low temperature, which is mainly determined by the Ni 3$d$ orbital. It is also found that the effective pairing interaction is enhanced as the on-site interaction increases, demonstrating that the superconductivity is driven by strong electron-electron correlation. Even though the $(π,π)$ antiferromagnetic correlation could be enhanced by electronic interaction, there is no evidence for long-range antiferromagnetic order exhibited in nickelate-based superconductors. Moreover, our results offer possible evidence that the pure electron correlation may not account for the charge density wave state observed in nickelates.
