Bright Quantum Dot Single-Photon Emitters at Telecom Bands Heterogeneously Integrated on Si

Abstract

Whereas the Si photonic platform is highly attractive for scalable optical quantum information processing, it lacks practical solutions for efficient photon generation. Self-assembled semiconductor quantum dots (QDs) efficiently emit photons in the telecom bands (1460–1625 nm) and allow for heterogeneous integration with Si. In this work, we report on a novel, robust, and industry-compatible approach for achieving single-photon emission from InAs/InP QDs heterogeneously integrated with a Si substrate. As a proof of concept, we demonstrate a simple vertical emitting device, employing a metallic mirror beneath the QD emitter, and experimentally obtained photon extraction efficiencies of ∼10%. Nevertheless, the figures of merit of our structures are comparable with values previously only achieved for QDs emitting at shorter wavelength or by applying technically demanding fabrication processes. Our architecture and the simple fabrication procedure allows for the demonstration of high-purity single-photon generation with a second-order correlation function at zero time delay, g (2)(τ = 0) < 0.02, without any corrections at continuous wave excitation at the liquid helium temperature and preserved up to 50 K. For pulsed excitation, we achieve the as-measured g (2)(0) down to 0.205 ± 0.020 (0.114 ± 0.020 with background coincidences subtracted).

Reflective dielectric cavity enhanced emission from hexagonal boron nitride spin defect arrays

“…The RDC consisting of microwave coplanar waveguides as a metal reflector and SiO 2 as a dielectric layer has been used for Raman and PL of other 2D materials, fluorescent nanodiamonds, and quantum dot enhancement. [46][47][48] Coupling V B − defects with this structure, the fluorescence intensity is enhanced 11 folds, and the ODMR contrast reaches ∼21%. This structure does not require complex micro-nano fabrication, and it is scalable and effective.…”

Fine-tunable near-critical Stranski-Krastanov growth of InAs/InP quantum dots

“…Ensembles of similar number density QDs can serve as the effective gain medium for lasing structures with a photonic crystal cavity [33,30]. However, the fabrication of nonclassical photon sources based on a single QD requires much lower surface densities leading to a substantial QD-to-QD separation [11,12]. The partially consumed WL between the QDs in Figure 1e is about 2 ML thinner than the one after As-P exchange (Fig.…”

Epitaxial quantum dots: a semiconductor launchpad for photonic quantum technologies

“…7(e), a quantum dot emitting around the telecom C-band is presented. Such a quantum dot is made of InAs by the droplet method on an InP substrate [69,283,310,311] . By tailoring the growth process, InAs quantum dots on a GaAs substrate can also emit at the telecom O-band or C-band [308,309] .…”

“…Internal conversion efficiencies of 5%–15% have been demonstrated in the silicon waveguides [303,304] and 12%–60% in micro-resonators [305–307] , where the limitation is mainly the phase mismatch. An alternative approach is to develop high-quality quantum dots directly at telecom wavelengths [69,107,172,283,308–310] . In this approach, losses due to wavelength conversion can be circumvented.…”