Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Role of electronic excitations in magneto-Raman spectra of graphene   We investigate the signature of the low-energy electronic excitations in the
Raman spectrum of monolayer and bilayer graphenes. The dominant contribution to
the Raman spectra is due to the interband electron-hole pairs, which belong to
the irreducible representation A$_2$ of the point group C$_{6v}$ of the
graphene lattice, and are characterised by crossed polarisation of incoming and
outgoing photons. At high magnetic fields, this is manifested by the excitation
of electron-hole (e-h) inter-Landau-level transitions with selection rule
$n^-\to n^+$. Weaker Raman-active inter-Landau-level modes also exist. One of
those has a selection rule similar to the infrared absorption process,
$n^-\to(n\pm1)^+$, but the created e-h excitation belongs to the irreducible
representation E$_2$ (rather than E$_1$) and couples to the optical phonon
mode, thus undergoing an anticrossing with the optical phonon G-line in Raman
in strong magnetic field. The fine structure of acquired by the G-line due to
such anticrossing depends on the carrier density, inhomogeneity of doping, and
presence of inhomogeneous strain in the sample.

22
The categories of this paper are: chao-dyn
7
The categories of this paper are: hep-th
8
The categories of this paper are: hep-ex
17
The categories of this paper are: q-fin
19
The categories of this paper are: eess
2
The categories of this paper are: math
30
The categories of this paper are: q-alg
9
The categories of this paper are: nlin
16
The categories of this paper are: stat
3
The categories of this paper are: physics
34
The categories of this paper are: chem-ph
36
The categories of this paper are: cmp-lg
33
The categories of this paper are: plasm-ph
5
The categories of this paper are: gr-qc
24
The categories of this paper are: dg-ga
29
The categories of this paper are: funct-an