Consistent picture of the octet-nodal gap and its evolution with doping in heavily overdoped Ba$_{1-x}$K$_{x}$Fe$_{2}$As$_{2}$

Shun-Li Yu; Zi-Jian Yao; Jian-Xin Li

doi:10.1088/0953-8984/27/50/505701

paper

Consistent picture of the octet-nodal gap and its evolution with doping in heavily overdoped Ba $_{1 - x}$ K $_{x}$ Fe $_{2}$ As $_{2}$

arXiv:1409.1988 · doi:10.1088/0953-8984/27/50/505701

Abstract

We investigate the pairing symmetry in heavily overdoped Ba $_{1 - x}$ K $_{x}$ Fe $_{2}$ As $_{2}$ based on the spin-fluctuation mechanism. 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 scatterings 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.

7 pages, 4 figures

Consistent picture of the octet-nodal gap and its evolution with doping in heavily overdoped Ba1−x​Kx​Fe2​As2​

Abstract

Consistent picture of the octet-nodal gap and its evolution with doping in heavily overdoped Ba $_{1 - x}$ K $_{x}$ Fe $_{2}$ As $_{2}$