Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dirac and Weyl Superconductors in Three Dimensions   We introduce the concept of 3D Dirac (Weyl) superconductors (SC), which have
protected bulk four(two)-fold nodal points and surface Andreev arcs at zero
energy. We provide a sufficient criterion for realizing them in centrosymmetric
SCs with odd-parity pairing and mirror symmetry, e.g., the nodal phases of
Cu$_x$Bi$_2$Se$_3$. Pairs of Dirac nodes appear in a mirror-invariant plane
when the mirror winding number is nontrivial. Breaking mirror symmetry may gap
Dirac nodes producing a topological SC. Each Dirac node evolves to a nodal ring
when inversion-gauge symmetry is broken. A Dirac node may split into a pair of
Weyl nodes, only when time-reversal symmetry is broken.

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The categories of this paper are: funct-an
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The categories of this paper are: plasm-ph
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The categories of this paper are: adap-org
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The categories of this paper are: ao-sci
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The categories of this paper are: acc-phys
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The categories of this paper are: nucl-ex
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The categories of this paper are: math-ph
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The categories of this paper are: stat
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The categories of this paper are: mtrl-th
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The categories of this paper are: astro-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: alg-geom
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The categories of this paper are: q-alg
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The categories of this paper are: hep-lat
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The categories of this paper are: bayes-an
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The categories of this paper are: patt-sol