Efficient source of single photons: a single quantum dot in a micropost microcavity

Area of Science:

• Quantum Optics
• Solid-State Physics
• Nanotechnology

Background:

• Single semiconductor quantum dots are promising sources for quantum information processing.
• Efficiently coupling quantum emitters to optical modes is crucial for scalable quantum technologies.
• Previous methods suffered from low emission efficiencies and multi-photon probabilities.

Purpose of the Study:

• To demonstrate efficient, triggered single-photon generation.
• To enhance the emission rate of single photons into a well-defined optical mode.
• To suppress multi-photon emission from quantum dot sources.

Main Methods:

• Coupling a single semiconductor quantum dot to a 3D confined optical mode.
• Utilizing a micropost microcavity structure for enhanced light-matter interaction.
• Characterizing the spectral and temporal properties of the emitted photons.

Main Results:

• Achieved approximately 38% efficiency for emitting single photons into a single-mode traveling wave.
• Demonstrated a nearly 2 orders of magnitude improvement over bulk quantum dot emission.
• Reduced the probability of multi-photon emission by a factor of 7 compared to Poissonian light.

Conclusions:

• Micropost microcavities enable highly efficient single-photon sources.
• This approach significantly advances the performance of quantum dot-based photon generation.
• The demonstrated efficiency and photon indistinguishability are vital for future quantum networks and computing.