Electrical excitation of surface plasmons

TL;DR

This paper demonstrates a novel method where low-energy tunneling electrons excite surface plasmon polaritons in a gold nanowire, which are then converted into free photons, offering a voltage-controlled way to generate SPPs.

Contribution

It introduces a two-step momentum downconversion scheme that uses electron tunneling to excite and convert surface plasmons in nanostructures, a new approach in plasmonics.

Findings

Electron tunneling excites gap plasmons that couple to propagating SPPs.

The scheme enables voltage-controlled launching of SPPs.

Surface plasmons are converted into free photons at the nanowire end.

Abstract

We exploit a plasmon mediated two-step momentum downconversion scheme to convert low-energy tunneling electrons into propagating photons. Surface plasmon polaritons (SPPs) propagating along an extended gold nanowire are excited on one end by low-energy electron tunneling and are then converted to free-propagating photons at the other end. The separation of excitation and outcoupling proofs that tunneling electrons excite gap plasmons that subsequently couple to propagating plasmons. Our work shows that electron tunneling provides a non-optical, voltage-controlled and low-energy pathway for launching SPPs in nanostructures, such as plasmonic waveguides