Ferroelectric-Gated Terahertz Plasmonics on Graphene

TL;DR

This paper proposes ferroelectric-gated graphene nanoplasmonic devices that enable compact, low-power terahertz waveguides with negligible crosstalk, leveraging strong plasmon-phonon coupling and ferroelectric memory effects.

Contribution

It introduces a novel design of ferroelectric-gated graphene plasmonic devices with domain patterning for integrated terahertz applications.

Findings

Plasmonic wavelength of 100-200 nm at 3-4 THz

Negligible crosstalk at 50 nm separation

Potential for low-power electro-optical switching

Abstract

Inspired by recent advancement of low-power ferroelectic-gated memories and transistors, we propose a design of ferroelectic-gated nanoplasmonic devices based on graphene sheets clamped in ferroelectric crystals. We show that the two-dimensional plasmons in graphene strongly couple with the phonon-polaritons in ferroelectrics at terahertz frequencies, leading to characteristic modal wavelength of the order of 100--200 nm at only 3--4 THz. By patterning the ferroelectrics into different domains, one can produce compact on-chip plasmonic waveguides, which exhibit negligible crosstalk even at 50 nm separation distance. Harnessing the memory effect of ferroelectrics, low-power electro-optical switching can be achieved on these plasmonic waveguides.