Ballistic simulation of Ratchet effect in antidot lattices patterned on graphene

In this contribution, we investigate the mechanism governing the Ratchet effect in patterned monolayer graphene, at the ballistic nanoscale. Still smaller than currently achievable and manifacturable devices, the simulated structures serve to exemplify the dependence of charge scattering on the arrangement of lattice defects, i.e. clusters of atomic vacancies of triangular shape. The ballistic Ratchet effect is seen as cumulative multimode scattering of carriers in correspondence of the lattice discontinuities. An atomistic model, based on the Scattering Matrix method and making use of TB approximation, has been applied. The latter, in contrast with continuum models, like Dirac or Kubo-Drude derived formulas, is capable of describing abrupt discontinuities at sub-micrometric scales, where graphene is likely to preserve its outstanding properties. We believe that this work is a first step in the direction of engineering and design of devices based on the ballistic Ratchet effect, like RF and THz detectors.