Scalable performance in solid-state single-photon sources

TL;DR

This paper demonstrates scalable, high-performance solid-state single-photon sources using quantum dot-micropillar devices, achieving high brightness, purity, and indistinguishability suitable for quantum information applications.

Contribution

The work introduces quantum dot-micropillar devices with significantly improved brightness and indistinguishability, advancing solid-state photon sources towards scalable quantum technologies.

Findings

Absolute brightness of 14% at fiber output

Photon purity of 97.1-99.0%

Indistinguishability up to 70% over 33 photons

Abstract

The desiderata for an ideal photon source are high brightness, high single-photon purity, and high indistinguishability. Defining brightness at the first collection lens, these properties have been simultaneously demonstrated with solid-state sources, however absolute source efficiencies remain close to the 1% level, and indistinguishability only demonstrated for photons emitted consecutively on the few nanosecond scale. Here we employ deterministic quantum dot-micropillar devices to demonstrate solid-state single-photon sources with scalable performance. In one device, an absolute brightness at the output of a single-mode fibre of 14% and purities of 97.1-99.0% are demonstrated. When non-resontantly excited, it emits a long stream of photons that exhibit indistinguishability up to 70%---above the classical limit of 50%---even after 33 consecutively emitted photons, a 400 ns separation between them. Resonant excitation in other devices results in near-optimal indistinguishability values: 96% at short timescales, remaining at 88% in timescales as large as 463 ns, after 39 emitted photons. The performance attained by our devices brings solid-state sources into a regime suitable for scalable implementations.