Unity yield of deterministically positioned quantum dot single photon sources

TL;DR

This paper demonstrates a highly efficient, scalable platform for producing deterministic quantum dot single photon sources with 100% yield, high collection efficiency, and low multi-photon emission, suitable for integrated quantum photonics.

Contribution

It introduces a nanowire-based fabrication method for quantum dots with deterministic positioning and high uniformity, achieving near-ideal single photon emission characteristics.

Findings

Collection efficiency up to 83%

Multiphoton emission probability as low as 0.6%

Emission linewidths limited by pure dephasing

Abstract

We report on a platform for the production of single photon devices with a fabrication yield of 100%. The sources are based on InAsP quantum dots embedded within position-controlled bottom-up InP nanowires. Using optimized growth conditions, we produce large arrays of structures having highly uniform geometries. Collection efficiencies are as high as 83% and multiphoton emission probabilities as low as 0.6% with the distribution away from optimal values associated with the excitation of other charge complexes and re-excitation processes, respectively, inherent to the above-band excitation employed. Importantly, emission peak lineshapes have Lorentzian profiles indicating that linewidths are not limited by inhomogeneous broadening but rather pure dephasing, likely elastic carrier-phonon scattering due to a high phonon occupation. This work establishes nanowire-based devices as a viable route for the scalable fabrication of efficient single photon sources and provides a valuable resource for hybrid on-chip platforms currently being developed.