Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Non-trivial charge-to-spin conversion in ferromagnetic metal/Cu/Al2O3 by
  orbital transport
17
The categories of this paper are: q-fin
3
The categories of this paper are: physics
2
The categories of this paper are: math
7
The categories of this paper are: hep-th
15
The categories of this paper are: nucl-ex
30
The categories of this paper are: q-alg
37
The categories of this paper are: supr-con
14
The categories of this paper are: math-ph
16
The categories of this paper are: stat
36
The categories of this paper are: cmp-lg
18
The categories of this paper are: econ
0
The categories of this paper are: hep-ph
29
The categories of this paper are: funct-an
1
The categories of this paper are: cs
23
The categories of this paper are: solv-int
10
The categories of this paper are: q-bio