Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Anisotropic spin fluctuations in detwinned FeSe   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 = 3.7 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.

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The categories of this paper are: eess
10
The categories of this paper are: q-bio
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The categories of this paper are: nucl-ex
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The categories of this paper are: stat
1
The categories of this paper are: cs
8
The categories of this paper are: hep-ex
33
The categories of this paper are: plasm-ph
37
The categories of this paper are: supr-con
30
The categories of this paper are: q-alg
5
The categories of this paper are: gr-qc
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The categories of this paper are: funct-an
35
The categories of this paper are: mtrl-th
36
The categories of this paper are: cmp-lg
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The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
32
The categories of this paper are: atom-ph