Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Graphene wormhole trapped by external magnetic field   In this work we study the behavior of massless fermions in a graphene
wormhole and in the presence of an external magnetic field. The graphene
wormhole is made from two sheets of graphene that play the roles of
asymptotically flat spaces connected through a carbon nanotube with a zig-zag
boundary. We solve the massless Dirac equation in this geometry and analyze its
wave function. We show that the energy spectra of these solutions exhibit
similar behavior to Landau levels.

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The categories of this paper are: physics
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The categories of this paper are: patt-sol
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The categories of this paper are: q-bio
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The categories of this paper are: cs
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The categories of this paper are: chao-dyn
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The categories of this paper are: math-ph
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The categories of this paper are: q-fin
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The categories of this paper are: nucl-th
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The categories of this paper are: hep-lat
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The categories of this paper are: eess
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The categories of this paper are: funct-an
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The categories of this paper are: quant-ph
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The categories of this paper are: astro-ph
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The categories of this paper are: q-alg
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The categories of this paper are: nlin
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The categories of this paper are: acc-phys