Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Observation of pair tunneling and coherent destruction of tunneling in
  arrays of optical waveguides
17
The categories of this paper are: q-fin
12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
5
The categories of this paper are: gr-qc
1
The categories of this paper are: cs
32
The categories of this paper are: atom-ph
9
The categories of this paper are: nlin
31
The categories of this paper are: ao-sci
2
The categories of this paper are: math
27
The categories of this paper are: comp-gas
16
The categories of this paper are: stat
20
The categories of this paper are: acc-phys
22
The categories of this paper are: chao-dyn
23
The categories of this paper are: solv-int
15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th