Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Magnetic order and spin excitations in the Kitaev--Heisenberg model on
  the honeycomb lattice
20
The categories of this paper are: acc-phys
16
The categories of this paper are: stat
10
The categories of this paper are: q-bio
34
The categories of this paper are: chem-ph
0
The categories of this paper are: hep-ph
14
The categories of this paper are: math-ph
13
The categories of this paper are: quant-ph
12
The categories of this paper are: nucl-th
17
The categories of this paper are: q-fin
33
The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
31
The categories of this paper are: ao-sci
7
The categories of this paper are: hep-th
30
The categories of this paper are: q-alg
28
The categories of this paper are: alg-geom
8
The categories of this paper are: hep-ex