title: Magnonlike dispersion of spin resonance in Ni-doped BaFe2As2.
abstract: Inelastic neutron scattering measurements on Ba(Fe0.963Ni0.037)2As2 manifest a neutron spin resonance in the superconducting state with anisotropic dispersion within the Fe layer. Whereas the resonance is sharply peaked at the antiferromagnetic (AFM) wave vector Q(AFM) along the orthorhombic a axis, the resonance disperses upwards away from Q(AFM) along the b axis. In contrast to the downward dispersing resonance and hourglass shape of the spin excitations in superconducting cuprates, the resonance in electron-doped BaFe2As2 compounds possesses a magnonlike upwards dispersion.
authors.affiliation: Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA. mgkim@lbl.gov
authors.forename: M G
authors.initials: MG
authors.lastname: Kim
authors.forename: G S
authors.initials: GS
authors.lastname: Tucker
authors.forename: D K
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authors.lastname: Pratt
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authors.lastname: Ran
authors.forename: A
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authors.lastname: Thaler
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authors.lastname: Marty
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authors.lastname: Calder
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authors.lastname: Podlesnyak
authors.forename: S L
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authors.lastname: Bud'ko
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authors.lastname: Canfield
authors.forename: A
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authors.lastname: Kreyssig
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authors.lastname: Goldman
authors.forename: R J
authors.initials: RJ
authors.lastname: McQueeney