Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Lattice-Induced Double-Valley Degeneracy Lifting in Magnetic Field in
  Graphene   We show that the recently discovered double-valley splitting of the low-lying
Landau level(s) in the Quantum Hall Effect in graphene can be explained as
perturbative orbital interaction of intra- and inter-valley microscopic orbital
currents with a magnetic field. This effect is provided by the
translational-non-invariant terms corresponding to graphene's crystallographic
honeycomb symmetry but do not exist in the relativistic theory of massless
Dirac Fermions in Quantum Electrodynamics. We discuss recent data in view of
these results.

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The categories of this paper are: solv-int
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The categories of this paper are: atom-ph
36
The categories of this paper are: cmp-lg
25
The categories of this paper are: patt-sol
22
The categories of this paper are: chao-dyn
2
The categories of this paper are: math
17
The categories of this paper are: q-fin
1
The categories of this paper are: cs
12
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: acc-phys
27
The categories of this paper are: comp-gas
3
The categories of this paper are: physics
34
The categories of this paper are: chem-ph
0
The categories of this paper are: hep-ph
6
The categories of this paper are: astro-ph