Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spectral Narrowing via Quantum Coherence   We have studied the transmission of an optically thick Rb vapor that is
illuminated by monochromatic and noise broaden laser fields in Lambda
configuration. The spectral width of the beat signal between the two fields
after transmission through the atomic medium is more than 1000 times narrower
than the spectral width of this signal before the medium.

37
The categories of this paper are: supr-con
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The categories of this paper are: acc-phys
14
The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom
0
The categories of this paper are: hep-ph
26
The categories of this paper are: bayes-an
27
The categories of this paper are: comp-gas
29
The categories of this paper are: funct-an
3
The categories of this paper are: physics
15
The categories of this paper are: nucl-ex
11
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: ao-sci
12
The categories of this paper are: nucl-th
9
The categories of this paper are: nlin
30
The categories of this paper are: q-alg