Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Resonating-Valence-Bond Ground-state of CaV$_4$O$_9$ by the
  Gutzwiller-projected Schwinger-boson method   An antiferromagnetic Heisenberg model on a 1/5-depleted two-dimensional
square-lattice, a model of CaV$_4$O$_9$, is investigated by variational Monte
Carlo simulation. A prototype of a trial wave function is made by projecting
out the doubly occupied states from the Schwinger-boson mean-field solution.
Then variational Monte Carlo simulation is performed up to $40 \times 40 $
sites(including $320$ vacant sites). The optimized state has the lowest energy,
$-0.5510J$, ever reported. For this state energies of a dimer bond and a
plaquette bond, staggered magnetization, static structure factor, and
excitation spectrum are calculated. It is shown that the N\'eel order survives
and there is no gap at isotropic coupling.

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The categories of this paper are: gr-qc
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The categories of this paper are: astro-ph
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The categories of this paper are: hep-th
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The categories of this paper are: chao-dyn
0
The categories of this paper are: hep-ph
17
The categories of this paper are: q-fin
18
The categories of this paper are: econ
30
The categories of this paper are: q-alg
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The categories of this paper are: stat
32
The categories of this paper are: atom-ph
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The categories of this paper are: funct-an
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The categories of this paper are: dg-ga
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The categories of this paper are: math-ph
13
The categories of this paper are: quant-ph
31
The categories of this paper are: ao-sci
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The categories of this paper are: plasm-ph