title: Third-order terahertz response of gapped, nearly-metallic armchair graphene nanoribbons.
abstract: We use time dependent perturbation theory to study the terahertz nonlinear response of gapped intrinsic and extrinsic nearly-metallic armchair graphene nanoribbons of finite length under an applied electric field. Generally, the nonlinear conductances exhibit contributions due to single-photon, two-photon, and three-photon processes. The interference between each of these processes results in remarkably complex behavior for the third-order conductances, including quantum dot signatures that should be measurable with a relatively simple experimental configuration. Notably, we observe sharp resonances in the isotropic third-order response due to the Van Hove singularities in the density of states at one-, two-, and three-photon resonances. However, these resonances are absent in the anisotropic third-order response; a result of the overall symmetry of the system.
authors.affiliation: Department of Electrical and Computer Engineering, University of Iowa, Iowa City, IA 52242, USA.
authors.forename: Yichao
authors.initials: Y
authors.lastname: Wang
authors.forename: David R
authors.initials: DR
authors.lastname: Andersen