Ultrabright source of entangled photon pairs

Area of Science:

• Quantum Information Science
• Solid-State Physics
• Quantum Optics

Background:

• Entangled photon pair sources are crucial for quantum information science but suffer from low generation rates.
• Existing methods like parametric conversion and quantum dots have limitations in efficiency and extraction.

Purpose of the Study:

• To overcome the low extraction efficiency of quantum dot-based entangled photon sources.
• To develop a solid-state triggered source of entangled photon pairs with improved performance.

Main Methods:

• Coupling a single quantum dot to a 'photonic molecule' optical cavity.
• Utilizing optical lithography for deterministic coupling to quantum dot energy states.
• Employing the Purcell effect to enhance emission into cavity modes.

Main Results:

• Achieved a polarization entangled photon pair rate of 0.12 per excitation pulse.
• Demonstrated an overall creation and collection efficiency of 80% for entangled photon pairs.
• Improved indistinguishability of optical recombination paths.

Conclusions:

• Coupling quantum dots to photonic molecule cavities significantly boosts entangled photon pair generation and collection rates.
• This approach paves the way for efficient, solid-state sources of entangled photons.
• Enables practical implementation of quantum computation and teleportation.