Unity yield of deterministically positioned quantum dot single photon sources.

Area of Science:

• Quantum optics
• Nanotechnology
• Materials science

Background:

• Single photon sources are crucial for quantum information processing.
• Existing methods face challenges in scalability and efficiency.
• Nanowire-based quantum dot devices offer potential for on-chip integration.

Purpose of the Study:

• To report a novel platform for producing single photon devices with high fabrication yield.
• To characterize the performance of these devices in terms of collection efficiency and multiphoton emission probability.
• To investigate the emission properties and underlying physical mechanisms.

Main Methods:

• Fabrication of position-controlled InP nanowires with embedded InAsP quantum dots using optimized growth conditions.
• Characterization of device geometry uniformity across large arrays.
• Measurement of collection efficiencies and multiphoton emission probabilities.
• Analysis of emission peak lineshapes to determine broadening mechanisms.

Main Results:

• Achieved 100% fabrication yield for single photon devices.
• Demonstrated high collection efficiencies (up to 83%) and low multiphoton emission probabilities (as low as 0.6%).
• Observed Lorentzian emission profiles, indicating linewidths limited by pure dephasing (likely carrier-phonon scattering) rather than inhomogeneous broadening.
• Uniform geometries across large arrays of nanowire structures.

Conclusions:

• Established nanowire-based devices as a viable route for scalable fabrication of efficient single photon sources.
• The platform provides a valuable resource for developing hybrid on-chip quantum platforms.
• Optimized growth conditions lead to high-performance single photon emitters with predictable emission characteristics.