Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spin-Excitation-Instability-Induced Quantum Phase Transitions in
  Double-Layer Quantum Hall Systems   We study intersubband spin density collective modes in double-layer quantum
Hall systems at $\nu=2$ within the time-dependent Hartree-Fock approximation.
We find that these intersubband spin density excitations may soften under
experimentally accessible conditions, signaling a phase transition to a new
quantum Hall state with interlayer inplane antiferromagnetic spin correlations.
We show that this novel canted antiferromagnetic phase is energetically stable
and that the phase transition is continuous.

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The categories of this paper are: astro-ph
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The categories of this paper are: q-bio
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The categories of this paper are: econ
24
The categories of this paper are: dg-ga
33
The categories of this paper are: plasm-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: chao-dyn
37
The categories of this paper are: supr-con
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The categories of this paper are: physics
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The categories of this paper are: funct-an
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The categories of this paper are: math
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The categories of this paper are: hep-th
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The categories of this paper are: eess
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The categories of this paper are: hep-ex
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The categories of this paper are: hep-ph
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The categories of this paper are: solv-int