Giant Faraday rotation of high-order plasmonic modes in graphene-covered nanowires

TL;DR

This paper predicts giant Faraday rotation in high-order plasmonic modes on graphene-coated nanowires, enabling magnetic control of plasmonic signals at mid-infrared frequencies with potential applications in nanophotonics.

Contribution

It introduces a theoretical prediction of large Faraday rotation in high-order SPP modes on graphene-coated nanowires, controllable via magnetic field and doping.

Findings

High-order plasmonic modes can be rotated by up to ~100 degrees.

Rotation angle is tunable through carrier concentration in graphene.

Giant Faraday rotation occurs at mid-infrared frequencies.

Abstract

Plasmonic Faraday rotation in nanowires manifests itself in the rotation of the spatial intensity distribution of high-order surface plasmon polariton (SPP) modes around the nanowire axis. Here we predict theoretically the giant Faraday rotation for SPP propagating on graphene-coated magneto-optically active nanowires. Upon the reversal of the external magnetic field pointing along the nanowire axis some high-order plasmonic modes may be rotated by up to ~ 100 degrees on scale of about 500 nm at mid-infrared frequencies. Tuning carrier concentration in graphene by chemical doping or gate voltage allows for controlling SPP-properties and notably the rotation angle of high-order azimuthal modes. Our results open the door to novel plasmonic applications ranging from nanowire-based Faraday isolators to the magnetic control in quantum-optical applications.