Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Screening effects on field emission from arrays of (5,5) carbon
  nanotubes: Quantum-mechanical simulation   The simulation of field electron emission from arrays of micrometer-long
open-ended (5, 5) carbon nanotubes is performed in the framework of quantum
theory of many electrons. It is found that the applied external field is
strongly screened when the spacing distance is shorter than the length of the
carbon nanotubes. The optimal spacing distance is two to three times of the
nanotube length, slightly depending on the applied external fields. The
electric screening can be described by a factor that is a exponential function
of the ratio of the spacing distance to the length of the carbon nanotubes. For
a given length, the field enhancement factor decreases sharply as the screening
factor larger than 0.05. The simulation implies that the thickness of the array
should be larger than a value but it does not help the emission much by
increasing the thickness a great deal.

7
The categories of this paper are: hep-th
27
The categories of this paper are: comp-gas
36
The categories of this paper are: cmp-lg
9
The categories of this paper are: nlin
12
The categories of this paper are: nucl-th
25
The categories of this paper are: patt-sol
15
The categories of this paper are: nucl-ex
20
The categories of this paper are: acc-phys
24
The categories of this paper are: dg-ga
13
The categories of this paper are: quant-ph
1
The categories of this paper are: cs
3
The categories of this paper are: physics
6
The categories of this paper are: astro-ph
35
The categories of this paper are: mtrl-th
32
The categories of this paper are: atom-ph
10
The categories of this paper are: q-bio