Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Enhancement of ultrafast demagnetization rate and Gilbert damping driven
  by femtosecond laser-induced spin currents in Fe81Ga19/Ir20Mn80 bilayers
5
The categories of this paper are: gr-qc
23
The categories of this paper are: solv-int
7
The categories of this paper are: hep-th
11
The categories of this paper are: hep-lat
9
The categories of this paper are: nlin
28
The categories of this paper are: alg-geom
27
The categories of this paper are: comp-gas
3
The categories of this paper are: physics
21
The categories of this paper are: adap-org
25
The categories of this paper are: patt-sol
1
The categories of this paper are: cs
14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
16
The categories of this paper are: stat
33
The categories of this paper are: plasm-ph