Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Schmidt modes and entanglement of biphoton polarization qutrits   Polarization features and entanglement of biphoton polarization qutrits are
briefly outlined. Schmidt modes of qutrits are found analytically and in a
general form by the method different from the standard one and based on the
original approach of Erhard Schmidt (1906)

30
The categories of this paper are: q-alg
25
The categories of this paper are: patt-sol
19
The categories of this paper are: eess
12
The categories of this paper are: nucl-th
15
The categories of this paper are: nucl-ex
33
The categories of this paper are: plasm-ph
28
The categories of this paper are: alg-geom
29
The categories of this paper are: funct-an
18
The categories of this paper are: econ
10
The categories of this paper are: q-bio
1
The categories of this paper are: cs
21
The categories of this paper are: adap-org
36
The categories of this paper are: cmp-lg
37
The categories of this paper are: supr-con
11
The categories of this paper are: hep-lat
31
The categories of this paper are: ao-sci