We compute the terahertz third-order nonlinear conductance of metallic armchair graphene nanoribbons using time-dependent perturbation theory. Significant enhancement of the intrinsic nonlinear third-order conductance over the result for intrinsic 2D single-layer graphene is observed over a wide range of temperatures and sample geometries. We also investigate the nonlinear response of extrinsic metallic acGNR with |Ef| much smaller than 200 meV. We find that the third-order conductance exhibits a strong Fermi level dependence at low temperatures. A third-order critical field strength of between roughly 1 and 5 kV/m is computed for the nonlinear Kerr terms as a function of temperature. For the third-harmonic terms, the minimum critical field is computed to be around 5 kV/m.
Wednesday, March 23, 2016
Abstract-First-principles study of the terahertz third-order nonlinear response of metallic armchair graphene nanoribbons
(Submitted on 19 Mar 2016)