Independent Electrical Control of Two Quantum Dots Coupled through a Photonic-Crystal Waveguide.

Area of Science:

• Quantum optics
• Solid-state physics
• Photonics

Background:

• Efficient light-matter interaction at the single-photon level is crucial for quantum technology.
• Controlling multiple quantum emitters simultaneously is challenging due to solid-state platform inhomogeneities.

Purpose of the Study:

• To demonstrate individually controllable semiconductor quantum dots coupled to a photonic-crystal waveguide.
• To enable scalable multi-emitter collective coupling for photonic quantum technology.

Main Methods:

• Fabrication of two semiconductor quantum dots coupled to a photonic-crystal waveguide.
• Application of local electric Stark fields for individual emitter control.
• Resonant transmission and fluorescence spectroscopy to probe coupling.
• Single-photon spectroscopy on a distant quantum dot.

Main Results:

• Demonstrated efficient coupling of two quantum dots to a waveguide.
• Achieved individual control of quantum dot emitters using electric fields.
• Utilized one quantum dot's single-photon stream for spectroscopy on another 16 μm away.
• Observed coherent coupling signatures between the emitters.

Conclusions:

• Presented a scalable method for multi-emitter collective coupling in solid-state systems.
• Overcame the challenge of individually addressing quantum emitters.
• Paved the way for deterministic solid-state photon emitters in quantum applications.