Surface plasmon polaritons on soft-boundary graphene nanoribbons and their application as voltage controlled plasmonic switches and frequency demultiplexers

TL;DR

This paper explores soft-boundary graphene nanoribbons supporting surface plasmon polaritons, demonstrating their potential as voltage-controlled plasmonic switches and frequency demultiplexers through mode manipulation and energy distribution control.

Contribution

It introduces a novel soft-boundary graphene nanoribbon structure and demonstrates its application in voltage-controlled plasmonic switching and frequency demultiplexing.

Findings

Identification of fundamental and higher-order modes with no cutoff frequency

Control of edge mode energy distribution via bias voltage

Proposal of a voltage-controlled plasmonic switch and demultiplexer

Abstract

A graphene sheet gated with a ridged ground plane, creating a soft-boundary (SB) graphene nanoribbon, is considered. By adjusting the ridge parameters and bias voltage a channel can be created on the graphene which can guide TM surface plasmon polaritons (SPP). Two types of modes are found; fundemental and higher-order modes with no apparent cutoff frequency and with energy distributed over the created channel, and edge modes with energy concen-trated at the soft-boundary edge. Dispersion curves, electric near-field patterns, and current distributions of these modes are determined. Since the location where energy is concentrated in the edge modes can be easily controlled electronically by the bias voltage and frequency, the edge-mode phenomena is used to propose a novel voltage controlled plasmonic switch and a plasmonic frequency demultiplexer.