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.

arXiv commentPRB(R), 2014

References in corpus (30)

• Magnetic Order versus superconductivity in the Iron-based layered La(O1-xFx)FeAs systems
• The Puzzle of High Temperature Superconductivity in Layered Iron Pnictides and Chalcogenides
• Gap symmetry and structure of Fe-based superconductors
• Resonant Spin Excitation in the High Temperature Superconductor Ba0.6K0.4Fe2As2
• Magnetism and its microscopic origin in iron-based high-temperature superconductors
• Normal-State Spin Dynamics and Temperature-Dependent Spin Resonance Energy in an Optimally Doped Iron Arsenide Superconductor
• The effect of collective spin-1 excitations on electronic spectra in high-Tc superconductors
• Two-dimensional resonant magnetic excitation in BaFe1.84Co0.16As2
• Three-dimensional Resonance in superconducting BaFe${}_{1.9}$Ni${}_{0.1}$As${}_2$
• The Synthesis and Characterization of LiFeAs and NaFeAs
• Control via electron count of the competition between magnetism and superconductivity in cobalt and nickel doped NaFeAs
• Crossover from weak to strong pairing in unconventional superconductors
• Phase Diagram and Calorimetric Properties of NaFe${}_{1-x}$Co${}_x$As
• Orbital-selective superconductivity, gap anisotropy and spin resonance excitations in a multiorbital t-J1-J2 model for iron pnictides
• Spin excitation anisotropy as a probe of orbital ordering in the paramagnetic tetragonal phase of superconducting BaFe1.904Ni0.096As2
• Splitting of resonance excitations in nearly optimally doped Ba(Fe0.94Co0.06)2As2: an inelastic neutron scattering study with polarization analysis
• Anisotropic Neutron Spin Resonance in Superconducting BaFe${}_{1.9}$Ni${}_{0.1}$As${}_2$
• Local magnetic anisotropy in BaFe${}_2$As${}_2$: a polarized inelastic neutron scattering study
• Distinguishing $s^{\pm }$ and $s^{++}$ electron pairing symmetries by neutron spin resonance in superconducting NaFe${}_{0.935}$Co${}_{0.045}$As
• Anisotropic but nodeless superconducting gap in the presence of spin density wave in iron-pnictide superconductor NaFe1-xCoxAs
• In-plane spin excitation anisotropy in the paramagnetic phase of NaFeAs
• Uniaxial pressure effect on structural and magnetic phase transitions in NaFeAs and its comparison with as-grown and annealed BaFe${}_2$As${}_2$
• Spin anisotropy of the resonance in superconducting FeSe0.5Te0.5
• Strong-Coupling Superconductivity in NaFe${}_{1-x}$Co${}_x$As: the Eliashberg Theory and Beyond
• Universality of dispersive spin-resonance mode in superconducting BaFe2As2
• Magnonlike dispersion of spin resonance in Ni-doped BaFe${}_2$As${}_2$
• Magnetic resonance from the interplay of frustration and superconductivity
• Double magnetic resonance and spin anisotropy in Fe-based superconductors due to static and fluctuating antiferromagnetic orders
• Microscopic coexistence of a two-component incommensurate spin density wave with superconductivity in underdoped NaFe${}_{0.983}$Co${}_{0.017}$As
• Spin-pairing and penetration depth measurements from nuclear magnetic resonance in NaFe${}_{0.975}$Co${}_{0.025}$As

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