Harvesting Excitons Through Plasmonic Strong Coupling

TL;DR

This paper demonstrates that strong coupling between quantum emitters and plasmonic nanostructures significantly enhances exciton transport, which can be tuned and occurs on ultrafast timescales, revealing new pathways for efficient energy transfer.

Contribution

It introduces a method to enhance and control exciton transport via plasmonic strong coupling, showing ultrafast transfer and the influence of dephasing effects.

Findings

Exciton conductance increases under strong coupling.

Transport properties can be tuned by plasmonic field shaping.

Ultrafast exciton transport occurs on a timescale of ~10 fs.

Abstract

Exciton harvesting is demonstrated in an ensemble of quantum emitters coupled to localized surface plasmons. When the interaction between emitters and the dipole mode of a metallic nanosphere reaches the strong coupling regime, the exciton conductance is greatly increased. The spatial map of the conductance matches the plasmon field intensity profile, which indicates that transport properties can be tuned by adequately tailoring the field of the plasmonic resonance. Under strong coupling, we find that pure dephasing can have detrimental or beneficial effects on the conductance, depending on the effective number of participating emitters. Finally, we show that the exciton transport in the strong coupling regime occurs on an ultrafast timescale given by the inverse Rabi splitting ($\sim10~$fs), orders of magnitude faster than transport through direct hopping between the emitters.