Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Intrinsic ferromagnetism and quantum anomalous Hall effect in CoBr2
  monolayer
13
The categories of this paper are: quant-ph
2
The categories of this paper are: math
9
The categories of this paper are: nlin
7
The categories of this paper are: hep-th
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org
23
The categories of this paper are: solv-int
15
The categories of this paper are: nucl-ex
5
The categories of this paper are: gr-qc
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
6
The categories of this paper are: astro-ph
31
The categories of this paper are: ao-sci
19
The categories of this paper are: eess
12
The categories of this paper are: nucl-th
24
The categories of this paper are: dg-ga