Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Bond-Operator Mean Field Theory for the Bilayer Heisenberg Model   Bond-operator mean field equations for the square-lattice, S=1/2 bilayer
Heisenberg model are developed and solved numerically. In the vicinity of both
the zero-field critical point and the field-induced transitions, comparisons
are made with T=0 and finite-temperature strong coupling expansions. The
mean-field theory suggests that the quantum critical region for the
field-induced transitions is restricted to significantly lower temperatures
than one might have concluded based on strong-coupling expansions or other
numerical studies.

9
The categories of this paper are: nlin
28
The categories of this paper are: alg-geom
13
The categories of this paper are: quant-ph
17
The categories of this paper are: q-fin
21
The categories of this paper are: adap-org
22
The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th
8
The categories of this paper are: hep-ex
26
The categories of this paper are: bayes-an
12
The categories of this paper are: nucl-th
33
The categories of this paper are: plasm-ph
0
The categories of this paper are: hep-ph
31
The categories of this paper are: ao-sci
3
The categories of this paper are: physics
18
The categories of this paper are: econ
27
The categories of this paper are: comp-gas