Direct observation of spin-orbit coupling in iron-based superconductors
Abstract
Spin-orbit coupling (SOC) is a fundamental interaction in solids which can induce a broad spectrum of unusual physical properties from topologically non-trivial insulating states to unconventional pairing in superconductors. In iron-based superconductors (IBS) its role has so far been considered insignificant with the models based on spin- or orbital fluctuations pairing being the most advanced in the field. Using angle-resolved photoemission spectroscopy we directly observe a sizeable spin-orbit splitting in all main families of IBS. We demonstrate that its impact on the low-energy electronic structure and details of the Fermi surface topology is much stronger than that of possible nematic ordering. Intriguingly, the largest pairing gap is always supported exactly by SOC-induced Fermi surfaces.
Keywords
Cite
@article{arxiv.1409.8669,
title = {Direct observation of spin-orbit coupling in iron-based superconductors},
author = {Sergey Borisenko and Danil Evtushinsky and Igor Morozov and Sabine Wurmehl and Bernd Büchner and Alexander Yaresko and Timur Kim and Moritz Hoesch and Thomas Wolf and Nikolai Zhigadlo},
journal= {arXiv preprint arXiv:1409.8669},
year = {2016}
}
Comments
Significant spin-orbit coupling is observed in all families of IBS. Figures 3 and 4 are new. Supplementary information is extended