Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spin excitation anisotropy in optimal-isovalent-doped superconductor
  BaFe2(As0.7P0.3)2   We use neutron polarization analysis to study spin excitation anisotropy in
the optimal-isovalent-doped superconductor BaFe2(As0.7P0.3)2 (Tc = 30 K).
Different from optimally hole and electron-doped BaFe2As2, where there is a
clear spin excitation anisotropy in the paramagnetic tetragonal state well
above Tc, we find no spin excitation anisotropy for energies above 2 meV in the
normal state of BaFe2(As0.7P0.3)2. Upon entering the superconducting state,
significant spin excitation anisotropy develops at the antiferromagnetic (AF)
zone center QAF = (1, 0, L = odd), while magnetic spectrum is isotropy at the
zone boundary Q = (1, 0, L = even). By comparing temperature, wave vector, and
polarization dependence of the spin excitation anisotropy in BaFe2(As0.7P0.3)2
and hole-doped Ba0.67K0.33Fe2As2 (Tc = 38 K), we conclude that such anisotropy
arises from spin-orbit coupling and is associated with the nearby AF order and
superconductivity.

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The categories of this paper are: acc-phys
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The categories of this paper are: math-ph
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The categories of this paper are: funct-an
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The categories of this paper are: math
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The categories of this paper are: gr-qc
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The categories of this paper are: bayes-an
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The categories of this paper are: cmp-lg
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The categories of this paper are: stat
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The categories of this paper are: econ
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The categories of this paper are: q-fin
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The categories of this paper are: hep-lat
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The categories of this paper are: hep-th
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The categories of this paper are: cs
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The categories of this paper are: chem-ph
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The categories of this paper are: plasm-ph
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The categories of this paper are: nlin