FeSe is an intriguing iron-based superconductor. It presents an unusual nematic state without magnetism and can be tuned to increase the critical superconducting temperature. Recently it has been observed a noteworthy anisotropy of the superconducting gaps. Its explanation is intimately related to the understanding of the nematic transition itself. Here we show that the spin-nematic scenario driven by orbital-selective spin-fluctuations provides a simple scheme to understand both phenomena. The pairing mediated by anisotropic spin modes is not only orbital selective but also nematic, leading to stronger pair scattering across the hole and X electron pocket. The delicate balance between orbital ordering and nematic pairing points also to a marked kz dependence of the hole-gap anisotropy.
@article{arxiv.1804.05800,
title = {Nematic Pairing from Orbital Selective Spin Fluctuations in FeSe},
author = {L. Benfatto and B. Valenzuela and L. Fanfarillo},
journal= {arXiv preprint arXiv:1804.05800},
year = {2018}
}
Comments
Main text: 6 pages + 5 figure + Supplementary Material. We added new numerical results obtained adding a pairing xy channel. We showed results for the Y electron pocket. We revised the discussion section in order to give a more balanced account of the differences with previous other works