Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Shot-noise limited monitoring and phase locking of the motion of a
  single trapped ion   We perform high-resolution real-time read-out of the motion of a single
trapped and laser-cooled Ba ion. By using an interferometric setup we
demonstrate shot-noise limited measurement of thermal oscillations with
resolution of 4 times the standard quantum limit. We apply the real-time
monitoring for phase control of the ion motion through a feedback loop,
suppressing the photon recoil-induced phase diffusion. Due to the spectral
narrowing in phase-locked mode, the coherent ion oscillation is measured with
resolution of about 0.3 times the standard quantum limit.

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The categories of this paper are: hep-ex
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The categories of this paper are: stat
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The categories of this paper are: nucl-ex
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The categories of this paper are: acc-phys
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The categories of this paper are: hep-lat
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The categories of this paper are: patt-sol
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The categories of this paper are: eess
2
The categories of this paper are: math
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The categories of this paper are: math-ph
21
The categories of this paper are: adap-org
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The categories of this paper are: hep-th
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The categories of this paper are: q-bio
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The categories of this paper are: bayes-an
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The categories of this paper are: ao-sci
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The categories of this paper are: dg-ga
12
The categories of this paper are: nucl-th