Unusual suppression of a spin resonance mode with magnetic field in underdoped NaFe${}_{1-x}$Co${}_x$As: Evidence for orbital-selective pairing

Yu Song, Guotai Tan, Chenglin Zhang +3

We use inelastic neutron scattering to study the fate of the two spin resonance modes in underdoped superconducting NaFe${}_{1-x}$Co${}_x$As ($x=0.0175$) under applied magnetic fields.…