  The strong light-matter interaction in graphene over a broad frequency range
has opened up a plethora of photonics applications of graphene. The goal of
this paper is to present the voltage tunability of plasmons in gated single-
and multi-layer graphene structures. Device concepts for plasmonic
interconnects and antennas and their performance for THz communication are
presented. For the first time, the role of gate voltage and the thickness of
the gate dielectric on the characteristics of plasmon propagation in graphene
are quantified by accounting for both the interface trap capacitance and the
quantum capacitance. The gate voltage serves as a powerful knob to tweak the
carrier concentration and allows building electrically reconfigurable terahertz
devices. By optimizing the gate voltage to maximize the plasmon propagation
length in a gated multi-layer graphene geometry, we derive simple scaling
trends that give intuitive insight into device modeling and design.
