Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Carrier Statistics and Quantum Capacitance of Graphene Sheets and
  Ribbons   In this work, fundamental results for carrier statistics in graphene
2-dimensional sheets and nanoscale ribbons are derived. Though the behavior of
intrinsic carrier densities in 2d graphene sheets is found to differ
drastically from traditional semiconductors, very narrow (sub-10 nm) ribbons
are found to be similar to traditional narrow-gap semiconductors. The quantum
capacitance, an important parameter in the electrostatic design of devices, is
derived for both 2d graphene sheets and nanoribbons.

17
The categories of this paper are: q-fin
6
The categories of this paper are: astro-ph
12
The categories of this paper are: nucl-th
5
The categories of this paper are: gr-qc
32
The categories of this paper are: atom-ph
31
The categories of this paper are: ao-sci
18
The categories of this paper are: econ
9
The categories of this paper are: nlin
8
The categories of this paper are: hep-ex
14
The categories of this paper are: math-ph
11
The categories of this paper are: hep-lat
2
The categories of this paper are: math
26
The categories of this paper are: bayes-an
0
The categories of this paper are: hep-ph
21
The categories of this paper are: adap-org
13
The categories of this paper are: quant-ph