Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum Coherence Effects in Four-level Diamond Atomic System   A symmetric four-level closed-loop $\diamondsuit$ type (the diamond
structure) atomic system driven by four coherent optical fields is
investigated. The system shows rich quantum interference and coherence
features. When symmetry of the system is broken, interesting phenomena such as
single and double dark resonances appear. As a result, the double
electromagnetically induced transparency effect is generated, which will
facilitate the implementation of quantum phase gate operation.

11
The categories of this paper are: hep-lat
12
The categories of this paper are: nucl-th
16
The categories of this paper are: stat
37
The categories of this paper are: supr-con
4
The categories of this paper are: cond-mat
24
The categories of this paper are: dg-ga
7
The categories of this paper are: hep-th
1
The categories of this paper are: cs
36
The categories of this paper are: cmp-lg
3
The categories of this paper are: physics
23
The categories of this paper are: solv-int
14
The categories of this paper are: math-ph
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
15
The categories of this paper are: nucl-ex
20
The categories of this paper are: acc-phys