Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Observation of the Berezinskii-Kosterlitz-Thouless transition in
  Boron-doped diamond films
3
The categories of this paper are: physics
18
The categories of this paper are: econ
7
The categories of this paper are: hep-th
35
The categories of this paper are: mtrl-th
0
The categories of this paper are: hep-ph
37
The categories of this paper are: supr-con
32
The categories of this paper are: atom-ph
24
The categories of this paper are: dg-ga
10
The categories of this paper are: q-bio
23
The categories of this paper are: solv-int
16
The categories of this paper are: stat
1
The categories of this paper are: cs
13
The categories of this paper are: quant-ph
6
The categories of this paper are: astro-ph
25
The categories of this paper are: patt-sol
22
The categories of this paper are: chao-dyn