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arXiv · 1308.3858

Spin excitation anisotropy as a probe of orbital ordering in the paramagnetic tetragonal phase of superconducting BaFe1.904Ni0.096As2

Huiqian Luo·Meng Wang·Chenglin Zhang·Louis-Pierre Regnault·Rui Zhang·Shiliang Li·Jiangping Hu·Pengcheng Dai
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Abstract

We use polarized neutron scattering to demonstrate that in-plane spin excitations in electron doped superconducting BaFe1.904Ni0.096As2 (Tc=19.8 K) change from isotropic to anisotropic in the tetragonal phase well above the antiferromagnetic (AF) ordering and tetragonal-to-orthorhombic lattice distortion temperatures (Tn=Ts=33 K) without an uniaxial pressure. While the anisotropic spin excitations are not sensitive to the AF order and tetragonal-to-orthorhombic lattice distortion, superconductivity induces further anisotropy for spin excitations along the [1,1,0] and [1,-1,0] directions. These results indicate that the spin excitation anisotropy is a probe of the electronic anisotropy or orbital ordering in the tetragonal phase of iron pnictides.

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Huiqian Luo, Meng Wang, Chenglin Zhang, Louis-Pierre Regnault, Rui Zhang, Shiliang Li, Jiangping Hu, Pengcheng Dai. 2013-08-18. Spin excitation anisotropy as a probe of orbital ordering in the paramagnetic tetragonal phase of superconducting BaFe1.904Ni0.096As2. https://doi.org/10.1103/physrevlett.111.107006

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