Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A three-state model with competing antiferromagnetic and pairing
  interactions   Motivated by the rich phase diagram of the high temperature superconductors,
we introduce a toy model with three state variables which can be interpreted as
two state particles and holes. The Hamiltonian has a term which favors
antiferromagnetism and an additional competing interaction which favors bonding
between pairs of antiparallel spins mediated by holes. For low concentration of
holes the dominant interaction between particles has antiferromagnetic
character, leading to an antiferromagnetic phase in the temperature-hole
concentration phase diagram, qualitatively similar to the antiferromagnetic
phase of doped Mott insulators. For growing concentration of holes
antiferromagnetic order is weakend and a phase with a different kind of order
mediated by holes appears. This last phase has the form of a dome in the T-hole
concentration plane. The whole phase diagram resembles those of some families
of high $T_c$ superconductors. We compute the phase diagram in the mean field
approximation and characterize the different phase transitions through Monte
Carlo simulations.

21
The categories of this paper are: adap-org
17
The categories of this paper are: q-fin
23
The categories of this paper are: solv-int
14
The categories of this paper are: math-ph
10
The categories of this paper are: q-bio
26
The categories of this paper are: bayes-an
5
The categories of this paper are: gr-qc
29
The categories of this paper are: funct-an
13
The categories of this paper are: quant-ph
0
The categories of this paper are: hep-ph
18
The categories of this paper are: econ
30
The categories of this paper are: q-alg
11
The categories of this paper are: hep-lat
8
The categories of this paper are: hep-ex
33
The categories of this paper are: plasm-ph
36
The categories of this paper are: cmp-lg