Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Antiferromagnetic ordering of energy levels for spin ladder with
  four-spin cyclic exchange: Generalization of the Lieb-Mattis theorem   The Lieb-Mattis theorem is generalized to an antiferromagnetic spin-ladder
model with four-spin cyclic exchange interaction. We prove that for J>2K, the
antiferromagnetic ordering of energy levels takes place separately in two
sectors, which remain symmetric and antisymmetric under the reflection with
respect to the longitudinal axis of the ladder. We prove also that at the
self-dual point J=2K, the Lieb-Mattis rule holds in the sectors with fixed
number of rung singlets. In both cases, it agrees with the similar rule for
Haldane chain with appropriate spin number.

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The categories of this paper are: cs
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The categories of this paper are: q-fin
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The categories of this paper are: physics
5
The categories of this paper are: gr-qc
35
The categories of this paper are: mtrl-th
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The categories of this paper are: quant-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: q-bio
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The categories of this paper are: chao-dyn
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The categories of this paper are: acc-phys
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The categories of this paper are: dg-ga
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The categories of this paper are: hep-ph
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The categories of this paper are: bayes-an
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The categories of this paper are: q-alg
37
The categories of this paper are: supr-con
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The categories of this paper are: cmp-lg