Nanoscale modeling of three-contacts graphene ballistic junctions: Analysis of the non-linear transport

In this contribution, three terminal ballistic junctions, made of three-branch graphene nanoribbons (GNRs), are modeled at the nanometric scale. This configuration is used for the realization of rectifiers, harmonic generator, mixers, switches. The analysis is carried in the frequency (energy) domain by a scattering matrix approach, optimized for GNR devices. The ballisticity and the scattering properties of the junction give rise to a nonlinear behavior as, in fact, a sinusoidal voltage between two GNR branches results in a non-sinusoidal current at the third branch. The input-output characteristic is predicted at the nanoscale, and it depends on several cooperating factors, namely the potential distribution and the geometry of the junction. Several numerical examples are reported to illustrate the above concepts.