Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Landau quantization and the thickness limit of topological insulator
  thin films of Sb2Te3
33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
6
The categories of this paper are: astro-ph
0
The categories of this paper are: hep-ph
16
The categories of this paper are: stat
34
The categories of this paper are: chem-ph
9
The categories of this paper are: nlin
37
The categories of this paper are: supr-con
29
The categories of this paper are: funct-an
18
The categories of this paper are: econ
10
The categories of this paper are: q-bio
21
The categories of this paper are: adap-org
2
The categories of this paper are: math
27
The categories of this paper are: comp-gas
17
The categories of this paper are: q-fin