Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Controlling the spin orientation of photoexcited electrons by symmetry
  breaking
13
The categories of this paper are: quant-ph
1
The categories of this paper are: cs
12
The categories of this paper are: nucl-th
18
The categories of this paper are: econ
23
The categories of this paper are: solv-int
5
The categories of this paper are: gr-qc
22
The categories of this paper are: chao-dyn
31
The categories of this paper are: ao-sci
24
The categories of this paper are: dg-ga
8
The categories of this paper are: hep-ex
3
The categories of this paper are: physics
6
The categories of this paper are: astro-ph
17
The categories of this paper are: q-fin
36
The categories of this paper are: cmp-lg
7
The categories of this paper are: hep-th
26
The categories of this paper are: bayes-an