Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Arbitrary spin-controlled directional coupling of surface plasmon
  polaritons
5
The categories of this paper are: gr-qc
32
The categories of this paper are: atom-ph
6
The categories of this paper are: astro-ph
1
The categories of this paper are: cs
13
The categories of this paper are: quant-ph
2
The categories of this paper are: math
15
The categories of this paper are: nucl-ex
26
The categories of this paper are: bayes-an
30
The categories of this paper are: q-alg
31
The categories of this paper are: ao-sci
19
The categories of this paper are: eess
22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat
8
The categories of this paper are: hep-ex
35
The categories of this paper are: mtrl-th
9
The categories of this paper are: nlin