Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: s-f(d) exchange mechanism of magnon generation by slow spinpolarons   It is shown that in a single-axis antiferromagnetic semiconductor placed in a
strong magnetic field, dispersionless magnons start emitting at any arbitrarily
small velocity of an electron occurring in a spinpolaron state. If magnons are
dispersed they are generated when the spinpolaron velocity exceeds the minimum
phase velocity of magnons. The maximum power of magnon generation caused by the
drift of spinpolarons is estimated.

28
The categories of this paper are: alg-geom
13
The categories of this paper are: quant-ph
35
The categories of this paper are: mtrl-th
2
The categories of this paper are: math
30
The categories of this paper are: q-alg
18
The categories of this paper are: econ
1
The categories of this paper are: cs
10
The categories of this paper are: q-bio
8
The categories of this paper are: hep-ex
0
The categories of this paper are: hep-ph
27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat
32
The categories of this paper are: atom-ph
9
The categories of this paper are: nlin
37
The categories of this paper are: supr-con