Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Electric Field-Dependent Charge-Carrier Velocity in Semiconducting
  Carbon Nanotubes   Charge transport in semiconducting single-walled nanotubes (SWNTs) with
Schottky-barrier contacts has been studied at high bias. We observe nearly
symmetric ambipolar transport with electron and hole currents significantly
exceeding 25 micron-ampere, the reported current limit in metallic SWNTs due to
optical phonon emission. Four simple models for the field-dependent velocity
(ballistic, current saturation, velocity saturation, and constant mobility) are
studied in the unipolar regime; the high-bias behavior is best explained by a
velocity saturation model with a saturation velocity of 2 x 10^7 cm/s.

35
The categories of this paper are: mtrl-th
1
The categories of this paper are: cs
27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
7
The categories of this paper are: hep-th
37
The categories of this paper are: supr-con
8
The categories of this paper are: hep-ex
18
The categories of this paper are: econ
3
The categories of this paper are: physics
17
The categories of this paper are: q-fin
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
10
The categories of this paper are: q-bio
28
The categories of this paper are: alg-geom
20
The categories of this paper are: acc-phys
0
The categories of this paper are: hep-ph