Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: To use or not to use cool superconductors?   The high critical temperature and magnetic field in cuprates and Fe-based
superconductors are not enough to assure applications at higher temperatures.
Making these superconductors useful involves complex and expensive technologies
to address many conflicting physics and materials requirements.

7
The categories of this paper are: hep-th
2
The categories of this paper are: math
5
The categories of this paper are: gr-qc
16
The categories of this paper are: stat
19
The categories of this paper are: eess
27
The categories of this paper are: comp-gas
3
The categories of this paper are: physics
22
The categories of this paper are: chao-dyn
32
The categories of this paper are: atom-ph
6
The categories of this paper are: astro-ph
1
The categories of this paper are: cs
28
The categories of this paper are: alg-geom
29
The categories of this paper are: funct-an
17
The categories of this paper are: q-fin
9
The categories of this paper are: nlin
26
The categories of this paper are: bayes-an