Reconfigurable sensor and nanoantenna by graphene-tuned Fano resonance.

Abstract

With the rapid developments in compact devices, the multi-function and reconfigurability of nanostructures are highly appreciated, while still very challenging. A majority of devices are usually mono-functional or hard to switch between different functions in one design. In this paper, we proposed graphene-wrapped core-shell nanowires to realize real-time reconfigurable sensors and nanoantenna by tuning the Fermi energies of graphene layers at the surfaces of core and shell, respectively. Owing to the electromagnetic coupling between the two graphene layer, two corresponding Fano resonances of scattering can arise in the Terahertz spectrum, which arises from the interference of bright modes and dark modes. Around the Fano resonances, the scattering can be considerably resonant (as an antenna) or suppressed (as a sensor). Interestingly, the field distributions are distinct at the suppressed scattering states for the two Fano resonances. The presented reconfigurable nanostructures may offer promising potentials for integrated and multi-functional electromagnetic control such as dynamic sensing and emission.