Light emission in nanogaps: overcoming quenching

Area of Science:

• Plasmonics
• Quantum Optics
• Nanophotonics

Background:

• Coupling quantum emitters with plasmonic nanogaps yields large spontaneous-emission-rate enhancements (∼1000).
• This effect is attributed to subwavelength light emission facilitated by small nanogap modes.
• Concerns exist regarding radiation efficiency and metal absorption in narrow nanogaps.

Purpose of the Study:

• To analytically clarify why quantum emitters in nanogap antennas exhibit good efficiencies.
• To determine the conditions favoring high emission efficiency in these systems.
• To investigate the upper bound of achievable radiation efficiency.

Main Methods:

• Analytical derivations were performed in the limit of small gap thickness.
• Electromagnetic calculations were reviewed to assess absorption and quenching effects.

Main Results:

• Scattered electromagnetic calculations suggest low absorption and quenching despite emitter proximity to metal.
• Analytical derivations provide insight into the factors governing high efficiency in nanogap antennas.
• The study addresses the circumstances under which high efficiency is obtained.

Conclusions:

• Quantum emitters in nanogap antennas can achieve high radiation efficiencies.
• Understanding the conditions for optimal efficiency is crucial for nanophotonic applications.
• The research clarifies the fundamental physics behind efficient light-matter interactions at the nanoscale.