Nuclear magnetic relaxation and superfluid density in Fe-pnictide superconductors: an anisotropic ±s-wave scenario

Abstract

We discuss the nuclear magnetic relaxation rate and the superfluid density with the use of the effective five-band model by Kuroki et al (2008 Phys. Rev. Lett. 101 087004) in Fe-based superconductors. We show that a fully gapped anisotropic ±s-wave superconductivity consistently explains experimental observations. In our phenomenological model, the gaps are assumed to be anisotropic on the electron-like β Fermi surfaces around the M point, where the maximum of the anisotropic gap is about four times larger than the minimum.