论文标题
$（s+id）$配对的混合价相关金属的理论
Theory of $(s+id)$ pairing in mixed-valent correlated metals
论文作者
论文摘要
由于最近在平面镍盐中发现超导性的动机，以及在重毛力量超导体中的长期令人困惑的实验，我们研究了相关的$ d $ - 电子 - 与弱相关的电子频段相关的库珀配对。我们对具有额外杂交的$ d $ - 电子的有效$ t-j $型号进行自洽的大N计算。与以前对混合价系统的研究不同，我们关注参数制度，在这些参数方案中，这两个杂交频段都与确定配对对称性有关。为了足够强大的杂交，我们发现了一个可靠的$ s+id $配对，它会破坏混合价值制度中的时间反转和点组对称性。我们的结果说明了内在的多频段系统（例如重毛，诸如繁重的系统）如何支持许多高度非平凡的配对状态。他们还提供了对先前的$ s+id $配对现象学提案的推定微观实现，并提出了潜在的解决方案，以解决令人困惑的实验，例如u $ _ {1-x} $ _x $ _x $ _x $ $ _x $ $ _ {13} $，哪些表现出两种超级导出的相位过渡和完整的gapt at plations and Gapt at plotections $ _x $ be $ _x $ be。
Motivated by the recent discovery of superconductivity in square-planar nickelates as well as by longstanding puzzling experiments in heavy-fermion superconductors, we study Cooper pairing between correlated $d$-electrons coupled to a band of weakly-correlated electrons. We perform self-consistent large N calculations on an effective $t-J$ model for the $d$-electrons with additional hybridization. Unlike previous studies of mixed-valent systems, we focus on parameter regimes where both hybridized bands are relevant to determining the pairing symmetry. For sufficiently strong hybridization, we find a robust $s+id$ pairing which breaks time-reversal and point-group symmetries in the mixed-valent regime. Our results illustrate how intrinsically multi-band systems such as heavy-fermions can support a number of highly non-trivial pairing states. They also provide a putative microscopic realization of previous phenomenological proposals of $s+id$ pairing and suggest a potential resolution to puzzling experiments in heavy-fermion superconductors such as U$_{1-x}$Th$_x$Be$_{13}$ which exhibit two superconducting phase transitions and a full gap at lower temperatures.
