Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Competition between antiferromagnetic and charge density wave order in
  the half filled Hubbard-Holstein model   We present a determinant quantum Monte Carlo study of the competition between
instantaneous on-site Coulomb repulsion and retarded phonon-mediated attraction
between electrons, as described by the two dimensional Hubbard-Holstein model.
At half filling, we find a strong competition between antiferromagnetism (AFM)
and charge density wave (CDW) order. We demonstrate that a simple picture of
AFM-CDW competition that incorporates the phonon mediated attraction into an
effective-U Hubbard model requires significant refinement. Specifically,
retardation effects slow the onset of charge order, so that CDW order remains
absent even when the effective U is negative. This delay opens a window where
neither AFM nor CDW order is well established, and where there are signatures
of a possible metallic phase.

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The categories of this paper are: q-alg
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The categories of this paper are: plasm-ph
14
The categories of this paper are: math-ph
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The categories of this paper are: supr-con
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The categories of this paper are: cmp-lg
22
The categories of this paper are: chao-dyn
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The categories of this paper are: funct-an
12
The categories of this paper are: nucl-th
25
The categories of this paper are: patt-sol
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The categories of this paper are: eess
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The categories of this paper are: solv-int
11
The categories of this paper are: hep-lat
26
The categories of this paper are: bayes-an
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The categories of this paper are: econ
15
The categories of this paper are: nucl-ex
3
The categories of this paper are: physics