Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Magic density in a self-rephasing ensemble of trapped ultracold atoms   We investigate the collective spin dynamics of a self-rephasing bosonic
ensemble of $^{87}$Rb trapped in a 1D vertical optical lattice. We show that
the combination of the frequency shifts induced by atomic interactions and
inhomogeneous dephasing, together with the spin self-rephasing mechanism leads
to the existence of a `magic density': \textit{i.e} a singular operating point
where the clock transition is first-order insensitive to density fluctuations.
This feature is very appealing for improving the stability of quantum sensors
based on trapped pseudo-spin-1/2 ensembles. Ramsey spectroscopy of the
$|F=1,m_{F}=0\rangle\rightarrow|F=2,m_{F}=0\rangle$ hyperfine transition is in
qualitative agreement with a numerical model based on coupled Bloch equations
of motion for energy dependent spin vectors.

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The categories of this paper are: q-alg
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The categories of this paper are: adap-org
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The categories of this paper are: solv-int
9
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: stat
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The categories of this paper are: acc-phys
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The categories of this paper are: q-fin
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The categories of this paper are: comp-gas
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The categories of this paper are: eess
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The categories of this paper are: bayes-an
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The categories of this paper are: quant-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: q-bio
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The categories of this paper are: math-ph
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The categories of this paper are: dg-ga