Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Aharonov-Bohm-Coulomb Problem in Graphene Ring   We study the Aharonov-Bohm-Coulomb problem in a graphene ring. We
investigate, in particular, the effects of a Coulomb type potential of the form
$\xi/r$ on the energy spectrum of Dirac electrons in the graphene ring in two
different ways: one for the scalar coupling and the other for the vector
coupling. It is found that, since the potential in the scalar coupling breaks
the time-reversal symmetry between the two valleys as well as the effective
time-reversal symmetry in a single valley, the energy spectrum of one valley is
separated from that of the other valley, demonstrating a valley polarization.
In the vector coupling, however, the potential does not break either of the two
symmetries and its effect appears only as an additive constant to the spectrum
of Aharonov-Bohm potential. The corresponding persistent currents, the
observable quantities of the symmetry-breaking energy spectra, are shown to be
asymmetric about zero magnetic flux in the scalar coupling, while symmetric in
the vector coupling.

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The categories of this paper are: plasm-ph
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The categories of this paper are: ao-sci
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The categories of this paper are: comp-gas
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The categories of this paper are: econ
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The categories of this paper are: hep-lat
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The categories of this paper are: astro-ph
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The categories of this paper are: chem-ph
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The categories of this paper are: nlin
5
The categories of this paper are: gr-qc
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The categories of this paper are: chao-dyn
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The categories of this paper are: adap-org
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The categories of this paper are: nucl-th
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The categories of this paper are: bayes-an
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The categories of this paper are: math
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The categories of this paper are: hep-ph
1
The categories of this paper are: cs