Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Intersubband spin-density excitations in quantum wells with Rashba spin
  splitting
9
The categories of this paper are: nlin
21
The categories of this paper are: adap-org
2
The categories of this paper are: math
17
The categories of this paper are: q-fin
11
The categories of this paper are: hep-lat
31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn
14
The categories of this paper are: math-ph
1
The categories of this paper are: cs
18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol
13
The categories of this paper are: quant-ph
23
The categories of this paper are: solv-int
29
The categories of this paper are: funct-an
27
The categories of this paper are: comp-gas
20
The categories of this paper are: acc-phys