Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Optical phonon scattering and theory of magneto-polarons in a quantum
  cascade laser in a strong magnetic field
13
The categories of this paper are: quant-ph
36
The categories of this paper are: cmp-lg
14
The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc
30
The categories of this paper are: q-alg
3
The categories of this paper are: physics
0
The categories of this paper are: hep-ph
35
The categories of this paper are: mtrl-th
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ
33
The categories of this paper are: plasm-ph
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
23
The categories of this paper are: solv-int
29
The categories of this paper are: funct-an
32
The categories of this paper are: atom-ph