Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dynamical structure factors of S=1 bond-alternating Heisenberg chains   We calculate the dynamical structural factor of the S=1 bond-alternating
Heisenberg chain. In the Haldane phase, the lowest excited states form the
lower edge of the multimagnon continuum in $0 \leq q \leq q_c$ and the
one-magnon mode in $q_c \leq q \leq \pi$. As the system approaches the gapless
point, $q_c$ shifts towards $q=\pi$ and the largest integrated intensity of the
one-magnon mode is decreased. In the singlet-dimer phase, the one-magnon mode
appears in $0 \leq q \leq q_c$. As the bond-alternation becomes strong, $q_c$
shifts towards $q=\pi$. In the antiferromagnetic-ferromagnetic bond-alternation
region with a strong ferromagnetic coupling, the lowest excited states form the
lower edge of the multimagnon continuum in $0 \leq q \leq 0.2\pi$ and $0.8\pi
\leq q \leq \pi$, and the one-magnon mode appears in $0.2\pi<q<0.8\pi$. The
largest integrated intensity of the one-magnon mode is 93%, which is slightly
smaller than that in the S=1 Haldane-gap system. We further discuss the
dynamical structural factor in connection with the inelastic neutron-scattering
experiments.

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The categories of this paper are: eess
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The categories of this paper are: plasm-ph
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The categories of this paper are: math-ph
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The categories of this paper are: hep-th
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The categories of this paper are: comp-gas
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The categories of this paper are: stat
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The categories of this paper are: gr-qc
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The categories of this paper are: chem-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: atom-ph
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The categories of this paper are: supr-con
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The categories of this paper are: hep-ex
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The categories of this paper are: physics
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The categories of this paper are: astro-ph
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The categories of this paper are: nlin
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The categories of this paper are: patt-sol