Self-aligned deterministic coupling of single quantum emitter to nanofocused plasmonic modes

Area of Science:

• Quantum plasmonics
• Nanophotonics
• Quantum optics

Background:

• Quantum plasmonics studies light-emitter interactions for compact quantum control.
• Precisely coupling single emitters to plasmonic modes at the nanoscale is a significant challenge.
• Current methods rely on chance or complex nanopositioning.

Purpose of the Study:

• To demonstrate deterministic coupling between nanofocused plasmonic modes and single quantum dots (QDs).
• To achieve this coupling without requiring precise positioning of individual QDs.
• To enable scalable fabrication of quantum plasmonic devices.

Main Methods:

• Depositing a thin silver layer onto a site-controlled pyramid quantum dot (QD) wafer.
• Utilizing the silver-coated pyramid facets for three-dimensional plasmonic nanofocusing.
• Geometrically aligning the plasmonic mode with QDs at the pyramid apex.

Main Results:

• Deterministic coupling achieved between plasmonic modes and single QDs without active positioning.
• Significant enhancement of QD spontaneous emission rate, up to 22 ± 16.
• Consistent results across QDs emitting within a ~150-meV spectral range.

Conclusions:

• The developed method enables geometrically controlled, deterministic quantum plasmonic coupling.
• This approach facilitates high-yield fabrication of on-chip quantum devices.
• Potential applications include high-efficiency light-emitting devices and quantum information processing.