Abstract
We report on the pairing symmetry and the spin correlations in the Fe(Ni)-based superconductors RFe(Ni)AsO1−xFx (R=Pr, La), LiFeAs and Ba1−xKxFe2As2 single crystals, based on our extensive nuclear magnetic resonance and nuclear quadrupole resonance measurements. The spin susceptibility measured by the Knight shift decreases below Tc along all crystal directions, which indicates spin-singlet pairing. Evidence for multiple gaps is given. We find that the antiferromagnetic spin fluctuation is anisotropic in the spin space due to spin-orbit coupling, but becomes isotropic in the zero temperature limit, which points to spin-singlet superconductivity with nodeless gap.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
