Consistent picture of the octet-nodal gap and its evolution with doping in heavily overdoped Ba1-xKxFe2As2
Consistent picture of the octet-nodal gap and its evolution with doping in heavily overdoped Ba1-xKxFe2As2
复制标题
八位组节点间隙的一致图像及其随重度过量掺杂 Ba1-xKxFe2As2 中掺杂的演变
DOI：
10.1088/0953-8984/27/50/505701
复制
发表时间：
2015
影响因子：
2.7
通讯作者：
Li Jian-Xin
中科院分区：
文献类型：
--
作者：
Yu Shun-Li;Yao Zi-Jian;Li Jian-Xin
基于自旋涨落机制研究了重掺杂ba1−x K x fe2 As 2的对对称性。我们提出了一种不同于传统费米表面嵌套图的费米补丁机制。本文统一地解释了近年来实验观察到的超导隙的奇异八元节点和掺杂后隙的异常演化。我们证明了电子在费米补丁上的散射是导致不相称的自旋涨落的主要原因，从而导致费米表面依赖的多间隙结构，因为费米能级接近平坦带。此外，我们发现在Lifshitz跃迁点附近，d波配对态将优于s波配对态。
We investigate the pairing symmetry in heavily overdoped Ba 1− x K x Fe 2 As 2 based on the spin-fluctuation mechanism. We propose a Fermi-patch mechanism that is different from the conventional Fermi-surface-nesting picture. The exotic octet nodes of the superconducting gap and the unusual evolution of the gap with doping observed by the recent experiments are well explained in a unified manner. We demonstrate that the scattering of electrons on the Fermi patches is mainly responsible for the incommensurate spin fluctuations and consequently the Fermi-surface-dependent multi-gap structure, since the Fermi level is close to the flat band. In addition, we find that a d-wave pairing state will prevail over the s-wave pairing state around the Lifshitz transition point.