Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Parametric Excitation and Squeezing in a Many-Body Spin System   We demonstrate a new method to coherently excite and control the quantum spin
states of an atomic Bose gas using parametric excitation of the collective spin
by time varying the relative strength of the Zeeman and spin-dependent
collisional interaction energies at multiples of the natural frequency of the
system. Compared to the usual single-particle quantum control techniques used
to excite atomic spins (e.g. Rabi oscillations using rf or microwave fields),
the method demonstrated here is intrinsically many-body, requiring
inter-particle interactions. While parametric excitation of a classical system
is ineffective from the ground state, we show that in our quantum system,
parametric excitation from the quantum ground state leads to the generation of
quantum squeezed states.

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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: q-alg
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The categories of this paper are: chao-dyn
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The categories of this paper are: q-bio
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The categories of this paper are: atom-ph
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The categories of this paper are: solv-int
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The categories of this paper are: quant-ph
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The categories of this paper are: econ
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The categories of this paper are: hep-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: mtrl-th
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The categories of this paper are: hep-lat
31
The categories of this paper are: ao-sci
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The categories of this paper are: acc-phys
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The categories of this paper are: comp-gas