Plasmons in Graphene: Fundamental Properties and Potential Applications

Plasmons in graphene have intriguing fundamental properties and hold great potential for applications. They enable strong confinement of electromagnetic energy at subwavelength scales, which can be tuned and controlled via gate voltage, providing an advantage for graphene's plasmons over surface plasmons (SPs) on a metal-dielectric interface. They have been described for a large span of frequencies from terahertz up to infrared and even in the visible. We provide a critical review of the current knowledge of graphene plasmon properties (dispersion and linewidth) with particular emphasis on plasmonic losses and the competition between different decay channels, which are not yet fully understood. Plasmons in graphene provide an insight into interesting many-body effects such as those arising from the electron-phonon interaction and electron-electron interactions, including hybrid plasmon-phonon collective excitations (either with intrinsic or substrate phonons) and plasmarons. We provide a comparison of SPs on a metal-dielectric interface with plasmons in graphene and 2-D metallic monolayers. We finally outline the potential for graphene's plasmons for applications.