Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Two-Dimensional S=1 Quantum Heisenberg Antiferromagnet at Finite
  Temperatures   The temperature dependence of the correlation length, susceptibilities and
the magnetic structure factor of the two-dimensional spin-1 square lattice
quantum Heisenberg antiferromagnet are computed by the quantum Monte Carlo loop
algorithm (QMC). In the experimentally relevant temperature regime the
theoretically predicted asymptotic low temperature behavior is found to be not
valid. The QMC results however, agree reasonably well with the experimental
measurements of La2NiO4 even without considering anisotropies in the exchange
interactions.

9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
23
The categories of this paper are: solv-int
18
The categories of this paper are: econ
12
The categories of this paper are: nucl-th
36
The categories of this paper are: cmp-lg
8
The categories of this paper are: hep-ex
13
The categories of this paper are: quant-ph
1
The categories of this paper are: cs
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The categories of this paper are: astro-ph
7
The categories of this paper are: hep-th
15
The categories of this paper are: nucl-ex
25
The categories of this paper are: patt-sol
3
The categories of this paper are: physics
29
The categories of this paper are: funct-an