Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Understanding double-resonant Raman scattering in chiral carbon
  nanotubes: Diameter and energy dependence of the $D$ mode   We present a theoretical model to describe the double-resonant scattering
process in arbitrary carbon nanotubes. We use this approach to investigate the
defect-induced $D$ mode in CNTs and unravel the dependence of the $D$-mode
frequency on the CNT diameter and on the energy of the resonant optical
transition. Our approach is based on the symmetry of the hexagonal lattice and
geometric considerations, hence the method is independent of the exact model
that is chosen to describe the electronic band structure or the phonon
dispersion. We finally clarify the diameter dependence of this Raman mode that
was controversely discussed in the past and demonstrate that, depending on the
experimental conditions, in general two different dependencies can be measured.
We also prove that carbon nanotubes with arbitrary chiral index can exhibit a
$D$ mode in their Raman spectrum, in contrast to previous symmetry-based
arguments. Furthermore, we give a direct quantification of the
curvature-induced phonon frequency corrections of the $D$-mode in carbon
nanotubes with respect to graphite.

8
The categories of this paper are: hep-ex
0
The categories of this paper are: hep-ph
2
The categories of this paper are: math
5
The categories of this paper are: gr-qc
27
The categories of this paper are: comp-gas
22
The categories of this paper are: chao-dyn
24
The categories of this paper are: dg-ga
34
The categories of this paper are: chem-ph
3
The categories of this paper are: physics
35
The categories of this paper are: mtrl-th
13
The categories of this paper are: quant-ph
25
The categories of this paper are: patt-sol
33
The categories of this paper are: plasm-ph
12
The categories of this paper are: nucl-th
7
The categories of this paper are: hep-th
14
The categories of this paper are: math-ph