Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The isotope effect in the Hubbard model with local phonons   The isotope effect (IE) in the two-dimensional Hubbard model with Holstein
phonons is studied using the dynamical cluster approximation with quantum Monte
Carlo. At small electron-phonon (EP) coupling the IE is negligible. For larger
EP coupling there is a large and positive IE on the superconducting temperature
that decreases with increasing doping. A significant IE also appears in the
low-energy density of states, kinetic energy and charge excitation spectrum. A
negligible IE is found in the pseudogap and antiferromagnetic (AF) properties
at small doping whereas the AF susceptibility at intermediate doping increases
with decreasing phonon frequency $\omega_0$. This IE stems from increased
polaronic effects with decreasing $\omega_0$. A larger IE at smaller doping
occurs due to stronger polaronic effects determined by the interplay of the EP
interaction with stronger AF correlations. The IE of the Hubbard-Holstein model
exhibits many similarities with the IE measured in cuprate superconductors.

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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: quant-ph
3
The categories of this paper are: physics
2
The categories of this paper are: math
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The categories of this paper are: nucl-ex
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The categories of this paper are: math-ph
9
The categories of this paper are: nlin
0
The categories of this paper are: hep-ph
36
The categories of this paper are: cmp-lg
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The categories of this paper are: patt-sol
35
The categories of this paper are: mtrl-th
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The categories of this paper are: plasm-ph
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The categories of this paper are: atom-ph
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The categories of this paper are: q-fin
1
The categories of this paper are: cs