  Graphene has been shown to exhibit a nonlinear response due to its unique
band structure. In this paper, we study the terahertz (THz) response metallic
armchair graphene nanoribbons, specifically current density and Rabi
oscillations beyond the semiclassical Boltzman model. We performed quantum
mathematical modeling by first finding a solution to the unperturbed
Hamiltonian for a single Fermion in the dipole gauge and then applying a
polarized, THz electrical field. After writing the solution in terms of the
four eigenstates of the Dirac system, we numerically calculated the $x$ and $y$
components of the induced current density resulting from applying the terahertz
electrical field. Due to the inclusion of the Rabi Oscillation in our
calculation of the optical response, we predict both odd and even harmonics, as
well as continuum oscillations of the power density spectrum in the THz regime.
Lastly, we show a rapid decay of the power harmonics.
