Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Evidence for filamentary superconductivity nucleated at antiphase domain
  walls in antiferromagnetic CaFe$_2$As$_2$   Resistivity, magnetization and microscopic $^{75}$As nuclear magnetic
resonance (NMR) measurements in the antiferromagnetically ordered state of the
iron-based superconductor parent material CaFe$_2$As$_2$ exhibit anomalous
features that are consistent with the collective freezing of domain walls.
Below $T^*\approx 10$ K, the resistivity exhibits a peak and downturn, the bulk
magnetization exhibits a sharp increase, and $^{75}$As NMR measurements reveal
the presence of slow fluctuations of the hyperfine field. These features in
both the charge and spin response are strongly field dependent, are fully
suppressed by $H^*\approx 15$ T, and suggest the presence of filamentary
superconductivity nucleated at the antiphase domain walls in this material.

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The categories of this paper are: chem-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-lat
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The categories of this paper are: funct-an
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The categories of this paper are: solv-int
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The categories of this paper are: eess
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The categories of this paper are: acc-phys
2
The categories of this paper are: math
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The categories of this paper are: atom-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: q-alg
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The categories of this paper are: supr-con
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The categories of this paper are: patt-sol
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The categories of this paper are: q-fin
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The categories of this paper are: econ
22
The categories of this paper are: chao-dyn