Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Electromagnetically induced transparency in two channels of a $\Lambda$
  system   We show two channel electromagnetically induced transparency (EIT) spectra at
various optical power. The two channels are coupling field and probe field
absorption. It is shown that EIT width and intensity increases linearly with
pump power. A density matrix calculation is used to determine nature of EIT
spectra induced by optical field. It has been observed that EIT occurs in cases
when coupling laser is at fixed frequency while probe laser frequency is
scanned, when coupling laser is frequency scanned and probe is at fixed
frequency.

17
The categories of this paper are: q-fin
26
The categories of this paper are: bayes-an
27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci
30
The categories of this paper are: q-alg
7
The categories of this paper are: hep-th
35
The categories of this paper are: mtrl-th
12
The categories of this paper are: nucl-th
24
The categories of this paper are: dg-ga
37
The categories of this paper are: supr-con
32
The categories of this paper are: atom-ph
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
21
The categories of this paper are: adap-org
11
The categories of this paper are: hep-lat
4
The categories of this paper are: cond-mat