Graphene nanoelectromagnetics: From radio frequency, terahertz to mid-infrared

Abstract

Graphene nanoelectromagnetics has recently attracted tremendous research interest, as it merges two vibrant fields of study: plasmonics and nanoelectronics. In the relatively unexplored terahertz (THz) to mid-infrared (MIR) region, the collective oscillation of massless Dirac fermions in graphene can excite the propagating surface charge density waves (surface plasmon polaritons or SPP) tightly confined to the graphene surface. Graphene is the only known material whose equilibrium (non-equilibrium) conductivity can be tuned over a broad range, as a function of its Fermi (quasi-Fermi) level. Hence, the propagation, radiation and scattering properties of a graphene monolayer or graphenebased nanostructures can be dynamically tuned by chemical doping, electrostatic gating, or photopumping. Such tunable plasmonic properties open tremendous new possibilities in novel THz and infrared (IR) optoelectronic devices with compact size, ultrahigh speed, and low power consumption. In the visible (VIS) region, graphene has high optical transparency and good electrical conductivity, in addition to flexibility and robustness, thereby becoming a very promising material to be used as a transparent electrode in the next-generation flexible displays and solar panels. In the radio-frequency (RF) region, the graphene transistor is a good candidate for power amplifiers and frequency multipliers, due to its high carrier mobility and its unique ambipolar transport characteristics. In this chapter, we will review several of the most recent advances and potential applications of graphene nanoelectromagnetics in different spectral range.

Initial Access & Beam Alignment for mmWave and Terahertz Communications

“…SPPs also oscillate at optical frequencies, allowing them to convey data over wide bandwidths. In addition, Graphene is a two-dimensional form of graphite that has unique electronic and optical features [169]. Compared to traditional electronic materials, Graphene is highly tunable in terahertz frequencies as carrier densities can be easily managed by an electrical gating and doping [170]; thus, it can be used to implement devices that dynamic beamforming.…”