We present the behaviors of both dynamical and static spin susceptibilities of
doped gapped armchair graphene nanoribbon using the Green's function approach
in the context of Hubbard model Hamiltonian.
Specially, the effects of spin polarization and gap parameter
on the spin excitation modes of armchair graphene nanoribbon are investigated
via calculating correlation function of spin density operators.
The electron density
dependence of static charge structure factor of armchair graphene nanoribbon
is studied. The effects of both gap parameter and magnetic ordering
on the static structure factor
are discusses in details.
In experimental viewpoint, the spin excitaion plasmonic
modes of electron gas in graphene nanoribbon or the other systems
have been obtained by neutron scattering. Because neutrons have been coupled
with electrons
via spin degrees of freedom, the plasmonic spin excitation spectrum has been manifested.
In this theoretical work,
the dynamical spin susceptibility components have been calculated by
quantum many particle method.
The imaginary part of dynamical spin susceptibilities is proportional
to inelastic cross section of neutron beam. Thus the main research goal of this
work is the study of plasmonic
spectrum of graphene nanoribbon in the presence of electron electron interaction
via theoretical calculation of dynamical susceptibility. The frequency position of
sharp peaks in dynamical spin susceptibility presents the magnetic plasmonic
excitation spectrum of graphene nanoribbon.
The frequency position
of sharp peak in dynamical spin susceptibility introduces the
plasmonic oscillations of the mentioned nano structure.
The effects of magnetic ordering on the behavior of static and dynamical charge
susceptibilities have been focused.
Figure captions:
Fig1: Transverse dynamical
spin susceptibility of
undoped gapped graphene nanoribbon versus normalized frequency
for different values of gap parameter
and for zero magnetization at zero temperature
Fig2:Transverse dynamical
spin susceptibility of doped gapped
graphene nanoribbon versus normalized frequency
for different values of normalized chemical potential and for full spin polarization at
zero temperature.
