Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Performance of a prototype atomic clock based on lin||lin coherent
  population trapping resonances in Rb atomic vapor   We report on the performance of the first table-top prototype atomic clock
based on coherent population trapping (CPT) resonances with parallel linearly
polarized optical fields (lin||lin configuration). Our apparatus uses a
vertical cavity surface emitting laser (VCSEL) tuned to the D1 line of 87Rb
with current modulation at the 87Rb hyperfine frequency. We demonstrate
cancellation of the first-order light shift by proper choice of rf modulation
power, and further improve our prototype clock stability by optimizing the
parameters of the microwave lock loop. Operating in these optimal conditions,
we measured a short-term fractional frequency stability (Allan deviation)
2*10^{-11} tau^{-1/2} for observation times 1s<tau< 20s. This value is limited
by large VCSEL phase noise and environmental temperature fluctuation. Further
improvements in frequency stability should be possible with an apparatus
designed as a dedicated lin||lin CPT resonance clock with environmental impacts
minimized.

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The categories of this paper are: acc-phys
8
The categories of this paper are: hep-ex
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The categories of this paper are: adap-org
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The categories of this paper are: dg-ga
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The categories of this paper are: alg-geom
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The categories of this paper are: bayes-an
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The categories of this paper are: chem-ph
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The categories of this paper are: funct-an
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The categories of this paper are: nucl-th
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The categories of this paper are: atom-ph
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The categories of this paper are: q-alg
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The categories of this paper are: quant-ph
7
The categories of this paper are: hep-th
27
The categories of this paper are: comp-gas
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The categories of this paper are: cmp-lg
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The categories of this paper are: math-ph