Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Haldane gap for the S=2 antiferromagnetic Heisenberg chain revisited   Using the density matrix renormalization group (DMRG) technique, we carry out
a large scale numerical calculation for the S=2 antiferromagnetic Heisenberg
chain. Performing systematic scaling analysis for both the chain length $L$ and
the number of optimal states kept in the iterations $m$, the Haldane gap
$\Delta (2)$ is estimated accurately as $(0.0876\pm0.0013)J$. Our systematic
analysis for the S=2 chains not only ends the controversies arising from
various DMRG calculations and Monte Carlo simulations, but also sheds light on
how to obtain reliable results from the DMRG calculations for other complicated
systems.

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The categories of this paper are: alg-geom
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The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio
16
The categories of this paper are: stat
18
The categories of this paper are: econ
27
The categories of this paper are: comp-gas
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The categories of this paper are: cmp-lg
7
The categories of this paper are: hep-th
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The categories of this paper are: q-fin
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The categories of this paper are: dg-ga
5
The categories of this paper are: gr-qc
9
The categories of this paper are: nlin
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The categories of this paper are: solv-int
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The categories of this paper are: funct-an
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The categories of this paper are: nucl-th
31
The categories of this paper are: ao-sci