Wang, ChongZhang, RuiWang, FaLuo, HuiqianRegnault, L.P.Dai, PengchengLi, Yuan2016-03-242016-03-242013Wang, Chong, Zhang, Rui, Wang, Fa, et al.. "Longitudinal Spin Excitations and Magnetic Anisotropy in Antiferromagnetically Ordered BaFe2As2." <i>Physical Review X,</i> 3, no. 4 (2013) American Physical Society: 041036. http://dx.doi.org/10.1103/PhysRevX.3.041036.https://hdl.handle.net/1911/88642We report on a spin-polarized inelastic neutron-scattering study of spin waves in the antiferromagnetically ordered state of BaFe2As2. Three distinct excitation components are identified, with spins fluctuating along the c axis, perpendicular to the ordering direction in the ab plane and parallel to the ordering direction. While the first two “transverse” components can be described by a linear spin-wave theory with magnetic anisotropy and interlayer coupling, the third “longitudinal” component is generically incompatible with the local-moment picture. It points toward a contribution of itinerant electrons to the magnetism that is already in the parent compound of this family of Fe-based superconductors.engThis article is available under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.Journal articlehttp://dx.doi.org/10.1103/PhysRevX.3.041036