Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Microscopic mechanism of tunable band gap in potassium doped few-layer
  black phosphorus
32
The categories of this paper are: atom-ph
26
The categories of this paper are: bayes-an
25
The categories of this paper are: patt-sol
19
The categories of this paper are: eess
1
The categories of this paper are: cs
12
The categories of this paper are: nucl-th
36
The categories of this paper are: cmp-lg
9
The categories of this paper are: nlin
15
The categories of this paper are: nucl-ex
6
The categories of this paper are: astro-ph
28
The categories of this paper are: alg-geom
5
The categories of this paper are: gr-qc
21
The categories of this paper are: adap-org
18
The categories of this paper are: econ
14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga