2012/01/11 by N. Qureshi, P. Steffens, S. Wurmehl +3 · 1 citation
Physics and Astronomy · #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.86.060410
published as Phys. Rev. B 86, 060410(R) (2012) · 4 pages, 4 figures
arxiv created 2012/01/11 · arxiv updated 2013/10/17
The anisotropy of the magnetic excitations in BaFe2As2 was studied by polarized inelastic neutron scattering which allows one to separate the components of the magnetic response. Despite the in-plane orientation of the static ordered moment we find the in-plane polarized magnons to exhibit a larger gap than the out-of-plane polarized ones indicating very strong single-ion anisotropy within the layers. It costs more energy to rotate a spin within the orthorhombic \it a-b plane than rotating it perpendicular to the FeAs layers.