Buried spatially-regular array of spectrally ultra-uniform single quantum dots for on-chip scalable quantum optical circuits

TL;DR

This paper demonstrates the first buried, spatially ordered arrays of spectrally uniform single quantum dots with high purity, enabling scalable on-chip quantum optical circuits through flexible material synthesis and advanced photonic manipulation techniques.

Contribution

It introduces a novel synthesis of buried quantum dot arrays with high uniformity and purity, suitable for scalable on-chip quantum optical applications.

Findings

Quantum dot arrays with >99.5% single photon purity.

Spectral uniformity less than 2 nm across arrays.

Simulations show multifunctional photon manipulation over 20 nm bandwidth.

Abstract

A long standing obstacle to realizing highly sought on-chip monolithic solid state quantum optical circuits has been the lack of a starting platform comprising buried (protected) scalable spatially ordered and spectrally uniform arrays of on-demand single photon sources (SPSs). In this paper we report the first realization of such SPS arrays based upon a class of single quantum dots (SQDs) with single photon emission purity > 99.5% and uniformity < 2nm. Such SQD synthesis approach offers rich flexibility in material combinations and thus can cover the emission wavelength regime from long- to mid- to near-infrared to the visible and ultraviolet. The buried array of SQDs naturally lend themselves to the fabrication of quantum optical circuits employing either the well-developed photonic 2D crystal platform or the use of Mie-like collective resonance of all-dielectric building block based metastructures designed for directed emission and manipulation of the emitted photons in the horizontal planar architecture inherent to on-chip optical circuits. Finite element method-based simulations of the Mie-resonance based manipulation of the emitted light are presented showing achievement of simultaneous multifunctional manipulation of photons with large spectral bandwidth of ~ 20nm that eases spectral and mode matching. Our combined experimental and simulation findings presented here open the pathway for fabrication and study of on-chip quantum optical circuits.