Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Long-living dark coherence brought to light by magnetic-field controlled
  photon echo
14
The categories of this paper are: math-ph
3
The categories of this paper are: physics
2
The categories of this paper are: math
11
The categories of this paper are: hep-lat
32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an
1
The categories of this paper are: cs
24
The categories of this paper are: dg-ga
37
The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph
22
The categories of this paper are: chao-dyn
26
The categories of this paper are: bayes-an
34
The categories of this paper are: chem-ph
23
The categories of this paper are: solv-int
7
The categories of this paper are: hep-th
20
The categories of this paper are: acc-phys