Tuning and Persistent Switching of Graphene Plasmons on a Ferroelectric Substrate.

Goldflam, Michael D; Ni, Guang-Xin; Post, Kirk W; Fei, Zhe; Yeo, Yuting; Tan, Jun You; Rodin, Aleksandr S; Chapler, Brian C et al. · Nano Lett · 2015

basic_science · Level V

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Abstract

We characterized plasmon propagation in graphene on thin films of the high-κ dielectric PbZr0.3Ti0.7O3 (PZT). Significant modulation (up to ±75%) of the plasmon wavelength was achieved with application of ultrasmall voltages (< ±1 V) across PZT. Analysis of the observed plasmonic fringes at the graphene edge indicates that carriers in graphene on PZT behave as noninteracting Dirac Fermions approximated by a semiclassical Drude response, which may be attributed to strong dielectric screening at the graphene/PZT interface. Additionally, significant plasmon scattering occurs at the grain boundaries of PZT from topographic and/or polarization induced graphene conductivity variation in the interior of graphene, reducing the overall plasmon propagation length. Lastly, through application of 2 V across PZT, we demonstrate the capability to persistently modify the plasmonic response of graphene through transient voltage application.