Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Statistical mechanics of the Cluster-Ising model   We study a Hamiltonian system describing a three-spin-1/2 cluster-like
interaction competing with an Ising-like anti-ferromagnetic interaction. We
compute free energy, spin correlation functions and entanglement both in the
ground and in thermal states. The model undergoes a quantum phase transition
between an Ising phase with a nonvanishing magnetization and a cluster phase
characterized by a string order. Any two-spin entanglement is found to vanish
in both quantum phases because of a nontrivial correlation pattern.
Neverthless, the residual multipartite entanglement is maximal in the cluster
phase and dependent on the magnetization in the Ising phase. We study the block
entropy at the critical point and calculate the central charge of the system,
showing that the criticality of the system is beyond the Ising universality
class.

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The categories of this paper are: nlin
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The categories of this paper are: atom-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: acc-phys
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The categories of this paper are: chem-ph
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The categories of this paper are: math-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: adap-org
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The categories of this paper are: q-bio
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The categories of this paper are: dg-ga
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The categories of this paper are: eess
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The categories of this paper are: physics
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The categories of this paper are: patt-sol
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The categories of this paper are: econ
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The categories of this paper are: funct-an
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The categories of this paper are: supr-con