Optical Transparency Induced by a Largely Purcell Enhanced Quantum Dot in a Polarization-Degenerate Cavity

Area of Science:

• Quantum optics
• Solid-state physics
• Nanotechnology

Background:

• Strong light-matter interactions are crucial for quantum networks, often requiring high cooperativity between spin systems and photonic cavities.
• Photonic crystal cavities typically offer limited optical access, hindering coherent control of quantum information processing, especially with circularly polarized light.

Purpose of the Study:

• To demonstrate efficient optical access and high cooperativity coupling between a quantum dot and a novel cavity structure.
• To explore the potential of this system for quantum information processing and quantum network applications.

Main Methods:

• Fabrication of a bullseye cavity providing nearly degenerate and Gaussian polarization modes.
• Coupling an Indium Arsenide/Gallium Arsenide (InAs/GaAs) quantum dot to the bullseye cavity.
• Characterization of light-matter interactions, including cooperativity, Purcell enhancement, and cavity transparency.

Main Results:

• Achieved a high cooperativity of 8 for the quantum dot-bullseye cavity system.
• Observed significantly shortened spontaneous emission lifetimes (80 ps), indicating approximately 15-fold Purcell enhancement.
• Demonstrated ~80% transparency of light reflected from the cavity, enabling efficient optical accessing.

Conclusions:

• The bullseye cavity provides excellent optical access for coherent spin control, overcoming limitations of traditional photonic crystal cavities.
• The demonstrated high cooperativity and optical properties pave the way for advanced quantum information processing and photon switching applications.
• This work contributes to the development of robust quantum networks by enabling efficient light-matter interfaces.