Nature of magnetic excitations in superconducting BaFe${}_{1.9}$Ni${}_{0.1}$As${}_2$

Abstract

Since the discovery of the metallic antiferromagnetic (AF) ground state near superconductivity in iron-pnictide superconductors, a central question has been whether magnetism in these materials arises from weakly correlated electrons, as in the case of spin-density-wave in pure chromium, requires strong electron correlations, or can even be described in terms of localized electrons such as the AF insulating state of copper oxides. Here we use inelastic neutron scattering to determine the absolute intensity of the magnetic excitations throughout the Brillouin zone in electron-doped superconducting BaFe${}_{1.9}$Ni${}_{0.1}$As${}_2$ ($T_c=20$ K), which allows us to obtain the size of the fluctuating magnetic moment $<m^2>$, and its energy distribution. We find that superconducting BaFe${}_{1.9}$Ni${}_{0.1}$As${}_2$ and AF BaFe${}_2$As${}_2$ both have fluctuating magnetic moments $<m^2>\approx 3.2{\mu }_B^2$ per Fe(Ni), which are similar to those found in the AF insulating copper oxides. The common theme in both classes of high temperature superconductors is that magnetic excitations have partly localized character, thus showing the importance of strong correlations for high temperature superconductivity.

10 pages, 6 figures, to be published in Nature Physics

References in corpus (15)

• Magnetic Order versus superconductivity in the Iron-based layered La(O1-xFx)FeAs systems
• High-temperature superconductivity in iron-based materials
• Magnetic order in BaFe2As2, the parent compound of the FeAs based superconductors in a new structural family
• Strong Correlations and Magnetic Frustration in the High Tc Iron Pnictides
• Competing Orders and Spin-Density-Wave Instability in La(O${}_{1-x}$F${}_x$)FeAs
• Correlated electronic structure of LaOFeAs
• Ising and Spin orders in Iron-based Superconductors
• Multiband magnetism and superconductivity in Fe-based compounds
• Magnetism and Charge Dynamics in Iron Pnictides
• Two-dimensional resonant magnetic excitation in BaFe1.84Co0.16As2
• Spin fluctuations and superconductivity in a 3D tight-binding model for BaFe2As2
• Anomalous High-Energy Spin Excitations in La2CuO4
• Three-dimensional Resonance in superconducting BaFe${}_{1.9}$Ni${}_{0.1}$As${}_2$
• A neutron scattering study of the interplay between structure and magnetism in Ba(Fe${}_{1-x}$Co${}_x$)${}_2$As${}_2$
• Anisotropic itinerant magnetism and spin fluctuations in BaFe2As2: A neutron scattering study

Cited by in corpus (31)

• Strong electronic correlations from Hund's coupling
• Magnetism and its microscopic origin in iron-based high-temperature superconductors
• Iron based high transition temperature superconductors
• Orbital-selective Mott Phase in Multiorbital Models for Alkaline Iron Selenides K(1-x)Fe(2-y)Se2
• Electron doping evolution of the anisotropic spin excitations in BaFe2-xNixAs2
• CaMn${}_2$Sb${}_2$: Spin waves on a frustrated antiferromagnetic honeycomb lattice
• Optical conductivity of iron-based superconductors
• Spin-wave excitations and superconducting resonant mode in Cs(x)Fe(2-y)Se2
• On the separability of dynamical and non-local correlations in three dimensions
• The magnetic moment enigma in Fe-based high temperature superconductors
• On infrared pseudogap in cuprate and pnictide high-temperature superconductors
• Pressure Suppression of Electron Correlation in the Collapsed Tetragonal Phase of $CaF{e}_{2}A{s}_2$ : A DFT-DMFT Investigation
• Spin excitations in the nematic phase and the metallic stripe spin-density wave phase of iron pnictides
• Temperature dependence of the paramagnetic spin excitations in BaFe${}_2$As${}_2$
• Spectroscopic Evidence for Strong Quantum Spin Fluctuations with Itinerant Character in YFe2Ge2
• Spin excitations in optimally P-doped BaFe2(As0.7P0.3)2superconductor
• Local structural variation as source of magnetic moment reduction in BaFe2As2
• Crossover from spin-waves to diffusive spin excitations in underdoped Ba(Fe${}_{1-x}$Co${}_x$)${}_2$As${}_2$
• The onset of magnetism peaked around x=1/4 in optimally electron-doped LnFe(1-x)Ru(x)AsO(1-y)F(y) (Ln = La, Nd or Sm) superconductors
• Spin excitations in hole-overdoped iron-based superconductors
• Spin Waves and Spatially Anisotropic Exchange Interactions in the $\mathrm{S}=2$ Stripe Antiferromagnet Rb${}_{0.8}$Fe${}_{1.5}$S${}_2$
• Magnetic neutron scattering studies on the Fe-based superconductor system Fe${}_{1+y}$Te${}_{1-x}$Se${}_x$
• High-Energy Damping by Particle-Hole Excitations in the Spin-Wave Spectrum of Iron-Based Superconductors
• Overdamped antiferromagnetic strange metal state in Sr${}_3$IrRuO${}_7$
• Temperature and polarization dependence of low-energy magnetic fluctuations in nearly-optimal-doped NaFe${}_{0.9785}$Co${}_{0.0215}$As
• Anisotropic inplane spin correlation in the parent and Co-doped BaFe2As2: a neutron scattering study
• Paramagnetic spin excitations in insulating Rb${}_{0.8}$Fe${}_{1.6}$Se${}_2$
• The role of magnetic excitations in magnetoresistance and Hall effect of slightly TM-substituted BaFe${}_2$As${}_2$ compounds (TM = Mn, Cu, Ni)
• Spin fluctuations in the 112-type iron-based superconductor Ca${}_{0.82}$La${}_{0.18}$Fe${}_{0.96}$Ni${}_{0.04}$As${}_2$
• Strong local moment antiferromagnetic spin fluctuations in V-doped LiFeAs
• Band structure of organic-ion-intercalated (EMIM)${}_x$FeSe superconductor