Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum Hall effect on centimeter scale chemical vapor deposited
  graphene films   We report observations of well developed half integer quantum Hall effect
(QHE) on mono layer graphene films of 7 mm \times 7 mm in size. The graphene
films are grown by chemical vapor deposition (CVD) on copper, then transferred
to SiO_{2} /Si substrates, with typical carrier mobilities \approx 4000 cm^{2}
/Vs. The large size graphene with excellent quality and electronic homogeneity
demonstrated in this work is promising for graphene-based quantum Hall
resistance standards, and can also facilitate a wide range of experiments on
quantum Hall physics of graphene and practical applications exploiting the
exceptional properties of graphene.

15
The categories of this paper are: nucl-ex
16
The categories of this paper are: stat
22
The categories of this paper are: chao-dyn
21
The categories of this paper are: adap-org
32
The categories of this paper are: atom-ph
37
The categories of this paper are: supr-con
6
The categories of this paper are: astro-ph
31
The categories of this paper are: ao-sci
3
The categories of this paper are: physics
29
The categories of this paper are: funct-an
2
The categories of this paper are: math
23
The categories of this paper are: solv-int
10
The categories of this paper are: q-bio
20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
35
The categories of this paper are: mtrl-th