Anisotropic neutron spin resonance in underdoped superconducting NaFe1-xCoxAs

Abstract

We use polarized inelastic neutron scattering (INS) to study spin excitations in superconducting NaFe0.985Co0.015As (C15) with static antiferromagnetic (AF) order along the a-axis of the orthorhombic structure and NaFe0.935Co0.045As (C45) without AF order. In previous unpolarized INS work, spin excitations in C15 were found to have a dispersive sharp resonance near Er1=3.25 meV and a broad dispersionless mode at Er2=6 meV. Our neutron polarization analysis reveals that the dispersive resonance in C15 is highly anisotropic and polarized along the a- and c-axis, while the dispersionless mode is isotropic similar to that of C45. Since the a-axis polarized spin excitations of the anisotropic resonance appear below Tc, our data suggests that the itinerant electrons contributing to the magnetism are also coupled to the superconductivity.

PRB(R), 2014

References in corpus (9)

• Magnetic Order versus superconductivity in the Iron-based layered La(O1-xFx)FeAs systems
• Magnetism and its microscopic origin in iron-based high-temperature superconductors
• Two-dimensional resonant magnetic excitation in BaFe1.84Co0.16As2
• Three-dimensional Resonance in superconducting BaFe${}_{1.9}$Ni${}_{0.1}$As${}_2$
• Crossover from weak to strong pairing in unconventional superconductors
• Phase Diagram and Calorimetric Properties of NaFe${}_{1-x}$Co${}_x$As
• Anisotropic Neutron Spin Resonance in Superconducting BaFe${}_{1.9}$Ni${}_{0.1}$As${}_2$
• Anisotropic but nodeless superconducting gap in the presence of spin density wave in iron-pnictide superconductor NaFe1-xCoxAs
• Magnonlike dispersion of spin resonance in Ni-doped BaFe${}_2$As${}_2$

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• Spin-Excitations Anisotropy in the Bilayer Iron-Based Superconductor CaKFe${}_4$As${}_4$
• Neutron spin resonance as a probe of superconducting gap anisotropy in partially detwinned electron underdoped NaFe${}_{0.985}$Co${}_{0.015}$As
• Temperature and polarization dependence of low-energy magnetic fluctuations in nearly-optimal-doped NaFe${}_{0.9785}$Co${}_{0.0215}$As
• Fluctuating magnetism of Co- and Cu-doped NaFeAs
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