Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Observation of dual electromagnetically induced transparencies in cold
  $^{87}Rb$ atoms   We have observed two dual electromagnetically induced transparency (EIT)
spectra in probe transmission through cold $^{87}Rb$ atoms trapped in a
magneto-optical trap (MOT). These dual EIT peaks are generated in two different
N-systems formed by probe, coupling and control beams interacting with
different levels in $D_{2}$ line transitions of $^{87}Rb$ atom. The dependence
of spectral features of two N-systems on driving beams (\textit{i.e.} coupling
and control beams) strength and detuning has been investigated. The results
show that the dual EIT spectral features in both the N-systems can be
manipulated by varying the strength and detuning of both the driving beams. The
two N-systems have been modelled theoretically using a density matrix formalism
and results have shown a reasonable agreement with the experimental
observations.

20
The categories of this paper are: acc-phys
12
The categories of this paper are: nucl-th
21
The categories of this paper are: adap-org
7
The categories of this paper are: hep-th
36
The categories of this paper are: cmp-lg
24
The categories of this paper are: dg-ga
0
The categories of this paper are: hep-ph
31
The categories of this paper are: ao-sci
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
13
The categories of this paper are: quant-ph
18
The categories of this paper are: econ
2
The categories of this paper are: math
34
The categories of this paper are: chem-ph
22
The categories of this paper are: chao-dyn
5
The categories of this paper are: gr-qc