Spin Fluctuation of Fe-based Superconductors

Abstract

Spin fluctuations of iron-based superconductors are studied using unpolarized and polarized inelastic neutron scattering technique. Remarkable enhancement of magnetic signal at a specific energy is observed in superconducting phase, which is so called spin resonance. The spin resonance exhibits c-axis and spin-space anisotropy. The anisotropy could be attributed to three-dimensional antiferromagnetic correlations suggesting a strong relationship between the magnetism and superconductivity.