Cooperative energy transfer controls the spontaneous emission rate beyond field enhancement limits

TL;DR

This paper demonstrates that cooperative energy transfer in plasmonic nano-cavities can significantly accelerate spontaneous emission rates beyond traditional field enhancement limits, enabling dynamic optical modulation at room temperature.

Contribution

It introduces the concept of cooperative energy transfer from multiple emitters to enhance spontaneous emission rates in plasmonic nano-cavities, surpassing existing enhancement mechanisms.

Findings

Up to six-fold increase in emission rate observed.

The emission spectrum maintains plasmon resonance characteristics.

The cooperative effect is distinct from super-radiance.

Abstract

Quantum emitters located in proximity to a metal nanostructure individually transfer their energy via near-field excitation of surface plasmons. The energy transfer process increases the spontaneous emission (SE) rate due to plasmon-enhanced local field. Here, we demonstrate significant acceleration of quantum emitter SE rate in a plasmonic nano-cavity due to cooperative energy transfer (CET) from plasmon-correlated emitters. Using an integrated plasmonic nano-cavity, we realize up to six-fold enhancement in the emission rate of emitters coupled to the same nano-cavity on top of the plasmonic enhancement of the local density of states. The radiated power spectrum retains the plasmon resonance central frequency and lineshape, with the peak amplitude proportional to the number of excited emitters indicating that the observed cooperative SE is distinct from super-radiance. Plasmon-assisted CET offers unprecedented control over the SE rate and allows to dynamically control the spontaneous emission rate at room temperature enabling an SE rate based optical modulator.