Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Topological Objects in Two-gap Superconductor:I   We discuss topological objects, in particular the non-Abrikosov vortex and
the magnetic knot made of the twisted non-Abrikosov vortex, in two-gap
superconductor. We show that there are two types of non-Abrikosov vortex in
Ginzburg-Landau theory of two-gap superconductor, the D-type which has no
concentration of the condensate at the core and the N-type which has a
non-trivial profile of the condensate at the core, under a wide class of
realistic interaction potential. Furthermore, we show that we can construct a
stable magnetic knot by twisting the non-Abrikosov vortex and connecting two
periodic ends together, whose knot topology $\pi_3(S^2)$ is described by the
Chern-Simon index of the electromagnetic potential. We discuss how these
topological objects can be constructed in $\rm MgB_2$ or in liquid metallic
hydrogen.

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The categories of this paper are: stat
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The categories of this paper are: q-fin
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The categories of this paper are: adap-org
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The categories of this paper are: patt-sol
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The categories of this paper are: math
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The categories of this paper are: hep-lat
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The categories of this paper are: dg-ga
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The categories of this paper are: astro-ph
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The categories of this paper are: solv-int
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The categories of this paper are: nlin
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The categories of this paper are: atom-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: supr-con
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The categories of this paper are: mtrl-th
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The categories of this paper are: q-alg
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The categories of this paper are: physics