Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Correlations and Renormalization of the Electron-Phonon Coupling in the
  Honeycomb Hubbard Ladder and Superconductivity in Polyacene   We have performed extensive density matrix renormalization group (DMRG)
studies of the Hubbard model on a honeycomb ladder. The band structure (with
Hubbard U=0) exhibits an unusual quadratic band touching at half filling, which
is associated with a quantum Lifshitz transition from a band insulator to a
metal. %SAK as a function of a third-neighbor hopping parameter. For one
electron per site, non-zero $U$ drives the system into an insulating state in
which there is no pair-binding between added electrons; this implies that
superconductivity driven directly by the repulsive electron-electron
interactions is unlikely in the regime of small doping, $x\ll 1$. However, the
divergent density of states as $x\to 0$, the large values of the phonon
frequencies, and an unusual correlation induced enhancement of the
electron-phonon coupling imply that lightly doped polyacenes, which
approximately realize this structure, are good candidates for high temperature
electron-phonon driven superconductivity.

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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: funct-an
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The categories of this paper are: quant-ph
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The categories of this paper are: math-ph
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The categories of this paper are: eess
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The categories of this paper are: q-alg
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The categories of this paper are: nucl-th
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The categories of this paper are: chao-dyn
1
The categories of this paper are: cs
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The categories of this paper are: acc-phys
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The categories of this paper are: bayes-an
0
The categories of this paper are: hep-ph
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The categories of this paper are: astro-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: solv-int