Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Controlling the Spontaneous Emission Rate of Single Quantum Dots in a 2D
  Photonic Crystal
5
The categories of this paper are: gr-qc
10
The categories of this paper are: q-bio
2
The categories of this paper are: math
12
The categories of this paper are: nucl-th
7
The categories of this paper are: hep-th
23
The categories of this paper are: solv-int
1
The categories of this paper are: cs
14
The categories of this paper are: math-ph
6
The categories of this paper are: astro-ph
32
The categories of this paper are: atom-ph
22
The categories of this paper are: chao-dyn
3
The categories of this paper are: physics
16
The categories of this paper are: stat
0
The categories of this paper are: hep-ph
35
The categories of this paper are: mtrl-th
4
The categories of this paper are: cond-mat