Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Prediction of novel `magic' angles and correlations for twisted bilayer
  graphene in a perpendicular electric field   At certain angles of rotation called `magic angles' twisted bilayer graphene
features almost flat bands. The resulting strong correlations drive the system
to novel phases which have been observed in experiments recently. A complete
understanding of the `magic' angle physics---both at the single-particle as
well as the many-particle level---is still missing, and the search is ongoing.
Here, we identify a new set of `magic' angles, where locally flat bands with a
variety of possible many-body instabilities arise, but where the
single-particle problem admits an exact solution. This occurs in the presence
of an external perpendicular electric field at multicritical Lifshitz points.
At these angles, which can be quantified exactly, the central band features a
monkey saddle, resulting in strong electronic correlations.

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The categories of this paper are: bayes-an
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The categories of this paper are: chao-dyn
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The categories of this paper are: patt-sol
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The categories of this paper are: chem-ph
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The categories of this paper are: econ
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The categories of this paper are: solv-int
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The categories of this paper are: cmp-lg
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The categories of this paper are: atom-ph
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The categories of this paper are: math
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The categories of this paper are: q-bio
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The categories of this paper are: hep-lat
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The categories of this paper are: adap-org
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The categories of this paper are: astro-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: stat
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The categories of this paper are: nucl-ex