Active control of excitonic strong coupling and electroluminescence in electrically driven plasmonic nanocavities

TL;DR

This paper demonstrates electric control of excitonic strong coupling and electroluminescence in plasmonic nanocavities with semiconductor monolayers, enabling tunable light-matter interactions at the atomic scale for advanced nanophotonic devices.

Contribution

It introduces a method to reversibly modulate excitonic coupling and electroluminescence in nanocavities using electrical bias, integrating 2D semiconductors for active control.

Findings

Reversible modulation of Rabi splitting from ~102 to 80 meV with bias below 2.5 V.

Bias-controlled electroluminescence with quantum efficiency of ~3.5%.

Active control of light-matter interactions at the atomic scale.

Abstract

Enhancement and active control of light-matter interactions at the atomic scale is important for developing next-generation nanophotonic and quantum optical devices. Here, we demonstrate electric control of both excitonic strong coupling and electroluminescence by integrating semiconductor monolayers into a nanometer gap of electrically driven nanocube-on-mirror plasmonic nanocavities. Particularly, in a strongly-coupled system of nanocavity plasmons and WSe2 excitons, the ultra-strong electric field generated in the nanocavity gap enables a reversible modulation of the Rabi splitting between ~102 and 80 meV with a bias below 2.5 V. In the quantum tunnelling regime, by injecting carriers into a nanocavity-integrated WS2 monolayer, bias-controlled spectrally tunable electroluminescence from charged or neutral excitons is achieved with an external quantum efficiency reaching ~3.5%. These results underline practical approaches to electric control of atomic-scale light-matter interactions for applications including nanoscale light sources, ultrafast electro-optic modulation, quantum information processing and sensing.