Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Excitonic Phases from Weyl Semi-Metals   Systems with strong spin-orbit coupling, which competes with other
interactions and energy scales, offer a fertile playground to explore new
correlated phases of matter. Weyl semimetals are an example where the
phenomenon leads to a low energy effective theory in terms of massless linearly
dispersing fermions in three dimensions. In the absence of interactions
chirality is a conserved quantum number, protecting the semi-metallic physics
against perturbations that are translationally invariant. In this letter we
show that the interplay between interaction and topology yields a novel chiral
excitonic insulator. The state is characterized by a complex vectorial order
parameter leading to a gapping out of the Weyl nodes. A striking feature is
that it is ferromagnetic, with the phase of the order parameter determining the
direction of the induced magnetic moment.

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The categories of this paper are: q-bio
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The categories of this paper are: q-alg
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The categories of this paper are: q-fin
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The categories of this paper are: alg-geom
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The categories of this paper are: hep-ex
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The categories of this paper are: nucl-th
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The categories of this paper are: nucl-ex
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The categories of this paper are: comp-gas
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The categories of this paper are: plasm-ph
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The categories of this paper are: math
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The categories of this paper are: acc-phys
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The categories of this paper are: chao-dyn
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The categories of this paper are: hep-lat
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The categories of this paper are: stat
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The categories of this paper are: chem-ph
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The categories of this paper are: econ