Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Controlling the exchange interaction using the spin-flip transition of
  antiferromagnetic spins in Ni$_{81}$Fe$_{19}$ / $\alpha$-Fe$_2$O$_3$
20
The categories of this paper are: acc-phys
6
The categories of this paper are: astro-ph
32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an
30
The categories of this paper are: q-alg
19
The categories of this paper are: eess
2
The categories of this paper are: math
0
The categories of this paper are: hep-ph
3
The categories of this paper are: physics
34
The categories of this paper are: chem-ph
28
The categories of this paper are: alg-geom
14
The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph
9
The categories of this paper are: nlin
37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th