On chip scalable highly pure and indistinguishable single photon sources in ordered arrays: Path to Quantum Optical Circuits

TL;DR

This paper introduces a new platform of epitaxial quantum dots capable of producing highly pure, indistinguishable, and spatially ordered single photons on demand, advancing the development of scalable quantum photonic circuits.

Contribution

It presents a novel epitaxial quantum dot platform that achieves high purity, indistinguishability, and uniformity of single photon sources suitable for integrated quantum photonic networks.

Findings

Single photon purity >99% (g(2)(0) ~ 0.015)

Hong-Ou-Mandel interference visibility of 0.82 ± 0.03

Spectral nonuniformity less than 3 nm

Abstract

Realization of quantum optical circuits is at the heart of quantum photonic information processing. A long-standing obstacle however has been the absence of a platform of single photon sources (SPSs) that simultaneously satisfies the following required characteristics: spatially ordered SPS arrays that produce, on-demand, highly pure, and indistinguishable single photons with sufficiently uniform emission characteristics across the array, needed for controlled interference between photons from distinct sources to enable functional quantum optical networks. Here we report on such a platform of SPSs based upon a novel class of epitaxial quantum dots. Under resonant excitation, the SPSs (without Purcell enhancement) show single photon purity >99% (g(2)(0) ~ 0.015), high two-photon Hong-Ou-Mandel interference visibilities of 0.82 $\pm$ 0.03 (at 11.5K), and spectral nonuniformity <3nm - within established locally tunable technology. Our platform of SPSs paves the path to creating on-chip scalable quantum photonic systems.