论文标题
nematicity and Supercodutive：竞争与合作
Nematicity and superconductivity: Competition versus cooperation
论文作者
论文摘要
一段时间以来，已经在基于铁的超导体中识别并研究了电子列的行为，尤其是在众所周知的$ _2 $ AS $ _2 $系统中，它是众所周知的，可以与超导性竞争。另一方面，最近已经显示，FESE表现出非词性对超导过渡附近的超导性的可忽略的影响，并且当系统与S掺杂S时，两个顺序之间的实际合作是最近还提出了生命值在超导状态本身中经历一定的过渡。通常，我们预计，当超导与nematic秩序共存时，超导性将是各向异性的，但是在哪种情况下，两个订单竞争或合作，超导状态的各向异性如何与nematic状态相关。为了解决这个问题，我们研究了$ d $ - 波Pomeranchuk不稳定的简单平均场模型，以及混合的$ S，D $配对相互作用，并确定何时通过超导性增强或抑制了nematicity。我们表明，竞争或合作显着取决于相对于超导间隙函数的各向异性，由于nematicity性而导致费米表面的变形。此外，我们讨论了结果对FESE和生命的影响。
Electronic nematic behavior has been identified and studied in iron-based superconductors for some time, particularly in the well-known BaFe$_2$As$_2$ system, where it is well-known to compete with superconductivity. On the other hand, it has been shown recently that FeSe displays a negligible effect of nematicity on superconductivity near the superconducting transition, and actual cooperation between the two orders when the system is doped with S. Recently it has also been proposed that LiFeAs undergoes a nematic transition in the superconducting state itself. Generally, we expect superconductivity to be anisotropic when it coexists with nematic order, but it is not clear under what circumstances the two orders compete or cooperate, nor how the anisotropy of the superconducting state correlates with that in the nematic state. To address this, we study a simple mean field model of a $d$-wave Pomeranchuk instability together with a mixed $s,d$ pairing interaction, and identify when nematicity is enhanced or suppressed by superconductivity. We show that the competition or cooperation depends significantly on the distortion of the Fermi surface due to nematicity relative to the anisotropy of the superconducting gap function. Further, we discuss the implications of our results for FeSe and LiFeAs.
