Berlin 2018 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 25: Plasmonics and nanooptics: Light-matter interaction, spectroscopy II

O 25.4: Vortrag

Dienstag, 13. März 2018, 11:15–11:30, MA 041

Dopant-Induced Plasmon Decay in Graphene — •Dino Novko — Freie Universität, Institut für Chemie und Biochemie, Berlin

Unique properties of graphene plasmons, such as their tunability and low decay rates, have opened up many new pathways to control the electromagnetic energy on the nanoscale. Thus far the experimental studies have reported on graphene plasmons with up to far- or mid-infrared energies, which is achievable with the standard field gating techniques. On the other hand, theory predicts that chemically doped graphene could support plasmon excitations up to telecommunication or even visible frequencies. Apart from that, the presence of dopant may influence electron scattering mechanisms in graphene and thus impact the plasmon decay rate. Here I show a first-principles study of these effects in single-layer and bilayer graphene doped with various alkali and alkaline earth metals [D. Novko, Nano Lett. (2017)]. I find new dopant-activated damping channels: loss due to out-of-plane graphene and in-plane dopant vibrations, and electron transitions between graphene and dopant states. The latter excitations interact with the graphene plasmon and together they form a new hybrid mode. The study points out a strong dependence of these features on the type of dopants and the number of layers, which could be used as a tuning mechanism in future graphene-based plasmonic devices.