Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Ferroelectric PbTiO$_{3}$/SrRuO$_{3}$ superlattices with broken
  inversion symmetry
10
The categories of this paper are: q-bio
13
The categories of this paper are: quant-ph
37
The categories of this paper are: supr-con
2
The categories of this paper are: math
6
The categories of this paper are: astro-ph
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
19
The categories of this paper are: eess
27
The categories of this paper are: comp-gas
21
The categories of this paper are: adap-org
8
The categories of this paper are: hep-ex
23
The categories of this paper are: solv-int
36
The categories of this paper are: cmp-lg
22
The categories of this paper are: chao-dyn
25
The categories of this paper are: patt-sol
11
The categories of this paper are: hep-lat