Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spectrum and Screening cloud in the central spin model   We consider an electronic spin in a quantum dot, coupled to the surrounding
nuclear spins via inhomogeneous antiferromagnetic hyperfine interactions and
subject to a uniform field, which is described by Gaudin's central spin model.
We study spectral properties, the two-point correlation functions, and the
magnetization profile in the ground state and in low-lying excited states,
which characterizes the structure of the cloud of nuclear spins screening the
electron spin. A close connection to the pair occupation probability in the
BCS-model is established. Using the exact Bethe Ansatz solution of that model
and arguments of integrability, we can distinguish between contributions from
purely classical physics and from quantum fluctuations.

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The categories of this paper are: nlin
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The categories of this paper are: quant-ph
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The categories of this paper are: q-fin
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The categories of this paper are: chem-ph
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The categories of this paper are: hep-th
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The categories of this paper are: alg-geom
2
The categories of this paper are: math
32
The categories of this paper are: atom-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: acc-phys
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The categories of this paper are: cs
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The categories of this paper are: patt-sol
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The categories of this paper are: comp-gas
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The categories of this paper are: funct-an
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The categories of this paper are: bayes-an
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The categories of this paper are: chao-dyn