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arXiv · 1010.6204

Spin anisotropy of the resonance in superconducting FeSe0.5Te0.5

P. Babkevich·B. Roessli·S. N. Gvasaliya·L. -P. Regnault·P. G. Freeman·E. Pomjakushina·K. Conder·A. T. Boothroyd
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Abstract

We have used polarized-neutron inelastic scattering to resolve the spin fluctuations in superconducting FeSe0.5Te0.5 into components parallel and perpendicular to the layers. A spin resonance at an energy of 6.5 meV is observed to develop below T_c in both fluctuation components. The resonance peak is anisotropic, with the in-plane component slightly larger than the out-of-plane component. Away from the resonance peak the magnetic fluctuations are isotropic in the energy range studied. The results are consistent with a dominant singlet pairing state with s^{\pm} symmetry, with a possible minority component of different symmetry.

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P. Babkevich, B. Roessli, S. N. Gvasaliya, L. -P. Regnault, P. G. Freeman, E. Pomjakushina, K. Conder, A. T. Boothroyd. 2011-05-26. Spin anisotropy of the resonance in superconducting FeSe0.5Te0.5. https://doi.org/10.1103/physrevb.83.180506

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