Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Why all the fuss about 2D semiconductors?   Graphene is no longer alone; a family of atomically thin 2D semiconductors
has emerged. Optoelectronics and photonics applications are in their
experimental infancy but the future holds much promise.

19
The categories of this paper are: eess
17
The categories of this paper are: q-fin
13
The categories of this paper are: quant-ph
36
The categories of this paper are: cmp-lg
35
The categories of this paper are: mtrl-th
1
The categories of this paper are: cs
8
The categories of this paper are: hep-ex
15
The categories of this paper are: nucl-ex
37
The categories of this paper are: supr-con
24
The categories of this paper are: dg-ga
28
The categories of this paper are: alg-geom
30
The categories of this paper are: q-alg
7
The categories of this paper are: hep-th
11
The categories of this paper are: hep-lat
0
The categories of this paper are: hep-ph
32
The categories of this paper are: atom-ph