Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Superconductivity Near Phase Separation in Models of Correlated
  Electrons   Numerical and analytical studies of several models of correlated electrons
are discussed. Based on exact diagonalization and variational Monte Carlo
techniques, we have found strong indications that the two dimensional t-J model
superconducts near phase separation in the regime of quarter-filling density,
in agreement with previous results reported by Dagotto and Riera (Phys. Rev.
Letters 70, 682 (1993)). At this density the dominant channel is d_{x^2-y^2},
but a novel transition to s-wave superconductivity is observed decreasing the
electronic density. In addition, the one band t-U-V model has also been studied
using the mean-field approximation that accurately described the spin density
wave phase of the repulsive Hubbard model at half-filling. Finally, the two
band Hubbard model on a chain is also analyzed. Superconducting correlations
near phase separation exist in this model, as it occurs in the t-J model. Based
on these nontrivial examples it is $conjectured$ that electronic models tend to
have superconducting phases in the vicinity of phase separation.Reciprocally,
if it is established that a model that does not phase separate, then its
chances of presenting a superconducting phase are considerably reduced.

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The categories of this paper are: hep-lat
34
The categories of this paper are: chem-ph
20
The categories of this paper are: acc-phys
7
The categories of this paper are: hep-th
36
The categories of this paper are: cmp-lg
12
The categories of this paper are: nucl-th
29
The categories of this paper are: funct-an
26
The categories of this paper are: bayes-an
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
1
The categories of this paper are: cs
2
The categories of this paper are: math
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The categories of this paper are: econ
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The categories of this paper are: adap-org
5
The categories of this paper are: gr-qc
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The categories of this paper are: stat