Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: High performance THz emitters based on ferromagnetic/nonmagnetic
  heterostructures
33
The categories of this paper are: plasm-ph
0
The categories of this paper are: hep-ph
28
The categories of this paper are: alg-geom
8
The categories of this paper are: hep-ex
5
The categories of this paper are: gr-qc
9
The categories of this paper are: nlin
26
The categories of this paper are: bayes-an
7
The categories of this paper are: hep-th
11
The categories of this paper are: hep-lat
10
The categories of this paper are: q-bio
3
The categories of this paper are: physics
23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
12
The categories of this paper are: nucl-th
32
The categories of this paper are: atom-ph
19
The categories of this paper are: eess