2014/01/15 by Akira Satou, Y. Koseki, Satou, A. +7
Engineering · Physics and Astronomy · #FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Photonic Crystals and Applications #Plasmonic and Surface Plasmon Research #Thermal Radiation and Cooling Technologies
paper · pdf · doi:10.48550/arxiv.1401.3396
openalex publication_date 2014/01/15 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Coupling of plasmons in graphene at terahert (THz) frequencies with surface plasmons in a heavily-doped substrate is studied theoretically. We reveal that a huge scattering rate may completely damp out the plasmons, so that proper choices of material and geometrical parameters are essential to suppress the coupling effect and to obtain the minimum damping rate in graphene. Even with the doping concentration 1019 - 1020 cm-3 and the thickness of the dielectric layer between graphene and the substrate 100 nm, which are typical values in real graphene samples with a heavily-doped substrate, the increase in the damping rate is not negligible in comparison with the acoustic-phonon-limited damping rate. Dependence of the damping rate on wavenumber, thicknesses of graphene-to-substrate and gate-to-graphene separation, substrate doping concentration, and dielectric constants of surrounding materials are investigated. It is shown that the damping rate can be much reduced by the gate screening, which suppresses the field spread of the graphene plasmons into the substrate.