Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Anomalous Spectral Characteristics of Ultrathin sub-nm Colloidal CdSe
  Nanoplatelets   We demonstrate high quantum yield broad photoluminescence emission of
ultrathin sub-nanometer CdSe nanoplatelets (two-monolayer). They also exhibit
polarization-characterized lateral size dependent anomalous heavy hole and
light/split-off hole absorption intensities.

18
The categories of this paper are: econ
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
5
The categories of this paper are: gr-qc
25
The categories of this paper are: patt-sol
13
The categories of this paper are: quant-ph
9
The categories of this paper are: nlin
2
The categories of this paper are: math
20
The categories of this paper are: acc-phys
23
The categories of this paper are: solv-int
8
The categories of this paper are: hep-ex
28
The categories of this paper are: alg-geom
0
The categories of this paper are: hep-ph
33
The categories of this paper are: plasm-ph
15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th