The study of dynamical quasiparticle properties of undoped graphene nanoribbon

We have calculated the quasiparticle particle self-energy and spectral function in an undoped graphene nanoribbon when a symmetry breaking of the sublattice is occurred. Hubbard model Hamiltonian has been applied to describe the electron dynamics in the structure. Using the many body G0W approach and Green's function technique, we have found the dynamical quasiparticle properties of electrons on nanoribbon structure. Also random phase approximation has been exploited to calculate electronic self-energy of the system. The difference between on-site energies of atoms on two sublattices is named gap parameter. Specially, the effects of gap parameter and Hubbard parameter on spectral function, inelastic scattering lifetime and band gap renormalization have been studied. Also the wave vector dependence of inelastic scattering lifetime for different values of gap parameter has been investigated. In order to find the quasiparticle excitation spectrum of the interacting electronic system, we have studied the frequency dependence of spectral function for different physical parameters.