Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Sub- and super-luminal light propagation using a Rydberg state   We present a theoretical study to investigate sub- and super-luminal light
propagation in a rubidium atomic system consisting of a Rydberg state by using
density matrix formalism. The analysis is performed in a 4-level vee+ladder
system interacting with a weak probe, and strong control and switching fields.
The dispersion and absorption profiles are shown for stationary atoms as well
as for moving atoms by carrying out Doppler averaging at room temperature. We
also present the group index variation with control Rabi frequency and observe
that a transparent medium can be switched from sub- to super-luminal
propagation in the presence of switching field. Finally, the transient response
of the medium is discussed, which shows that the considered 4-level scheme has
potential applications in absorptive optical switching.

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The categories of this paper are: acc-phys
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The categories of this paper are: solv-int
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The categories of this paper are: nucl-th
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The categories of this paper are: dg-ga
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The categories of this paper are: stat
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The categories of this paper are: econ
29
The categories of this paper are: funct-an
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The categories of this paper are: nucl-ex
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The categories of this paper are: cond-mat
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The categories of this paper are: supr-con
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The categories of this paper are: math-ph
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The categories of this paper are: quant-ph
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The categories of this paper are: adap-org
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The categories of this paper are: ao-sci
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The categories of this paper are: comp-gas
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The categories of this paper are: atom-ph