Comparison of the resonant frequency in graphene and metallic nano-antennas

The scalability of the resonant frequency in graphene-based nano-antennas (graphennas) and metallic nano-antennas as a function of their length is analyzed. The antenna resonances are obtained by combining the dispersion relation in free-standing graphene and gold layers, respectively, with the resonance condition. Graphennas are found to have a better scalability in terms of their resonant frequency with respect to metallic nano-antennas as their length is reduced to a few mu m. These results open up the possibility to build micrometer-sized graphennas that resonate in the terahertz band, at a frequency up to two orders of magnitude below metallic nano-antennas with the same size. Graphennas are thereby envisaged to enable the implementation of wireless communications among nanosystems.