Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Linear and nonlinear superparamagnetic relaxation at high anisotropy
  barriers   The micromagnetic Fokker-Planck equation is solved for a uniaxial particle in
the low-temperature limit. Asymptotic series in the parameter that is the
inverse barrier height-to-temperature ratio are derived. With the aid of these
series, the expressions for the superparamagnetic relaxation time and the
odd-order dynamic susceptibilities are presented. The obtained formulas are
both quite compact and practically exact in the low (with respect to FMR)
frequency range that is proved by comparison with the numerically-exact
solution of the micromagnetic equation. The susceptibilities formulas contain
angular dependencies that allow to consider textured as well as randomly
oriented particle assemblies. Our results advance the previous two-level model
for nonlinear superparamagnetic relaxation.

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The categories of this paper are: eess
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The categories of this paper are: econ
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The categories of this paper are: atom-ph
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The categories of this paper are: mtrl-th
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The categories of this paper are: adap-org
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The categories of this paper are: stat
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The categories of this paper are: quant-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: cmp-lg
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The categories of this paper are: physics
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The categories of this paper are: q-alg
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The categories of this paper are: astro-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: nlin
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The categories of this paper are: ao-sci
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The categories of this paper are: q-fin