Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Revealing Hofstadter Spectrum for Graphene in a Periodic Potential   We calculate the energy bands for graphene monolayers when electrons move
through a periodic electrostatic potential in the presence of a uniform
perpendicular magnetic field. We clearly demonstrate the quantum fractal nature
of the energy bands at reasonably low magnetic fields. We present results for
the energy bands as functions of both wave number and magnetic flux through the
unit cells of the resulting moire superlattice. The effects due to pseudo-spin
coupling and Landau orbit mixing by a strong scattering potential have been
exhibited. At low magnetic fields when the Landau orbits are much larger than
the period of the modulation, the Landau levels are only slightly broadened.
This feature is also observed at extremely high magnetic fields. The density of
states has been calculated and shows a remarkable self-similarity like the
energy bands. We estimate that for modulation period of 10nm the region where
the Hofstadter butterfly is revealed at B < 2 T.

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The categories of this paper are: physics
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The categories of this paper are: quant-ph
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The categories of this paper are: ao-sci
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The categories of this paper are: cmp-lg
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The categories of this paper are: eess
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The categories of this paper are: math
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The categories of this paper are: astro-ph
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The categories of this paper are: bayes-an
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The categories of this paper are: comp-gas
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The categories of this paper are: acc-phys
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The categories of this paper are: hep-ex
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The categories of this paper are: chem-ph
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The categories of this paper are: nucl-th
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The categories of this paper are: q-fin
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The categories of this paper are: q-bio
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The categories of this paper are: math-ph