Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The MFA ground states for the extended Bose-Hubbard model with a
  three-body constraint   We address the intensively studied extended bosonic Hubbard model (EBHM) with
truncation of the on-site Hilbert space to the three lowest occupation states
n=0,1,2 in frames of the S=1 pseudospin formalism. Similar model was recently
proposed to describe the charge degree of freedom in a model high-Tc cuprate
with the on-site Hilbert space reduced to the three effective valence centers,
nominally Cu^{1+;2+;3+} . With small corrections the model becomes equivalent
to a strongly anisotropic S=1 quantum magnet in an external magnetic field. We
have applied a generalized mean-field approach and quantum Monte-Carlo
technique for the model 2D S=1 system with a two-particle transport to find the
ground state phase with its evolution under deviation from half-filling.

25
The categories of this paper are: patt-sol
18
The categories of this paper are: econ
33
The categories of this paper are: plasm-ph
15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th
13
The categories of this paper are: quant-ph
1
The categories of this paper are: cs
34
The categories of this paper are: chem-ph
9
The categories of this paper are: nlin
2
The categories of this paper are: math
19
The categories of this paper are: eess
10
The categories of this paper are: q-bio
32
The categories of this paper are: atom-ph
6
The categories of this paper are: astro-ph
8
The categories of this paper are: hep-ex
37
The categories of this paper are: supr-con