Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Preparation of ultracold atom clouds at the shot noise level   We prepare number stabilized ultracold clouds through the real-time analysis
of non-destructive images and the application of feedback. In our experiments,
the atom number ${N\sim10^6}$ is determined by high precision Faraday imaging
with uncertainty $\Delta_N$ below the shot noise level, i.e., $\Delta_N
<\sqrt{N}$. Based on this measurement, feedback is applied to reduce the atom
number to a user-defined target, whereupon a second imaging series probes the
number stabilized cloud. By this method, we show that the atom number in
ultracold clouds can be prepared below the shot noise level.

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The categories of this paper are: math
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The categories of this paper are: math-ph
15
The categories of this paper are: nucl-ex
20
The categories of this paper are: acc-phys
35
The categories of this paper are: mtrl-th
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The categories of this paper are: atom-ph
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The categories of this paper are: nucl-th
29
The categories of this paper are: funct-an
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The categories of this paper are: econ
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The categories of this paper are: gr-qc
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The categories of this paper are: hep-th
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The categories of this paper are: comp-gas
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The categories of this paper are: bayes-an
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The categories of this paper are: alg-geom
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The categories of this paper are: patt-sol
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The categories of this paper are: eess