%0 Journal Article
%A Chen, Tong
%A Chen, Youzhe
%A Kreisel, Andreas
%A Lu, Xingye
%A Schneidewind, Astrid
%A Qiu, Yiming
%A Park, J. T.
%A Perring, Toby G.
%A Stewart, J Ross
%A Cao, Huibo
%A Zhang, Rui
%A Li, Yu
%A Rong, Yan
%A Wei, Yuan
%A Andersen, Brian M.
%A Hirschfeld, P. J.
%A Broholm, Collin
%A Dai, Pengcheng
%T Anisotropic spin fluctuations in detwinned FeSe
%J Nature materials
%V 18
%N 7
%@ 1476-4660
%C Basingstoke
%I Nature Publishing Group
%M FZJ-2019-06642
%P 709 - 716
%D 2019
%X Superconductivity in FeSe emerges from a nematic phase that breaks four-fold rotational symmetry in the iron plane. This phase may arise from orbital ordering, spin fluctuations or hidden magnetic quadrupolar order. Here we use inelastic neutron scattering on a mosaic of single crystals of FeSe, detwinned by mounting on a BaFe2As2 substrate to demonstrate that spin excitations are most intense at the antiferromagnetic wave vectors QAF = (±1, 0) at low energies E = 6–11 meV in the normal state. This two-fold (C2) anisotropy is reduced at lower energies, 3–5 meV, indicating a gapped four-fold (C4) mode. In the superconducting state, however, the strong nematic anisotropy is again reflected in the spin resonance (E = 3.6 meV) at QAF with incommensurate scattering around 5–6 meV. Our results highlight the extreme electronic anisotropy of the nematic phase of FeSe and are consistent with a highly anisotropic superconducting gap driven by spin fluctuations.
%F PUB:(DE-HGF)16
%9 Journal Article
%$ pmid:31110345
%U <Go to ISI:>//WOS:000472020800016
%R 10.1038/s41563-019-0369-5
%U https://juser.fz-juelich.de/record/868049