Ballistic Ratchet effect on patterned graphene

Charge scattering from spatially asymmetric antidots patterned on graphene has been investigated, in the ballistic scale. The Scattering Matrix (SM) approach, formally equivalent to the Non Equilibrium Green's Function method, but particularly suitable for large structures, has been applied in order to evaluate the electron/hole distribution in patterned graphene upon injection of charge from metal contacts. The mathematical formulation of the SM method has been reviewed and commented. The presented work can be the basis for a systematic study of the Ratchet effect in the above kind of structure. A completely deterministic characterization of this effect is proposed, based on the scattering of asymmetric defects under external electromagnetic excitation. The Ratchet effect could be usefully exploited to realize high frequency detectors, sensors, and harvesting devices