Dispersion of the superconducting spin resonance in underdoped and antiferromagnetic BaFe2As2
American Physical Society
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Physics and AstronomyAmes Laboratory
Inelastic neutron-scattering measurements have been performed on underdoped Ba(Fe1-xCox)(2)As-2 (x=4.7%) where superconductivity and long-range antiferromagnetic (AFM) order coexist. The magnetic spectrum found in the normal state is strongly damped and develops into a magnetic resonance feature below T-c that has appreciable dispersion along c axis with a bandwidth of 3-4 meV. This is in contrast to the optimally doped x=8.0% composition, with no long-range AFM order, where the resonance exhibits a much weaker dispersion. [see M. D. Lumsden et al., Phys. Rev. Lett. 102, 107005 (2009).] The results suggest that the resonance dispersion arises from interlayer spin correlations present in the AFM ordered state.
This article is published as Pratt, D. K., A. Kreyssig, S. Nandi, N. Ni, A. Thaler, M. D. Lumsden, W. Tian et al. "Dispersion of the superconducting spin resonance in underdoped and antiferromagnetic BaFe 2 As 2." Physical Review B 81, no. 14 (2010): 140510. DOI: 10.1103/PhysRevB.81.140510. Copyright 2010 American Physical Society. Posted with permission.