Semiconductor quantum dots have emerged as an excellent platform for quantum light generation, providing quantum pure single photon wavepackets with unparalleled efficiency. These devices have started to accelerate the development of optical quantum technologies – notably in the field of optical quantum computing. In this talk, I will discuss our progresses toward the deterministic source, the use of these sources for the generation of linear cluster states and the generation of quantum light state using spontaneous emission as a resource for entanglement in the photon number basis.
Semiconductor quantum dots have emerged as an excellent platform for quantum light generation, providing quantum pure single photon wavepackets with unparalleled efficiency. These devices have started to accelerate the development of optical quantum technologies – notably in the field of optical quantum computing. In this talk, I will discuss our progresses toward the deterministic source, the use of these sources for the generation of linear cluster states and the generation of quantum light state using spontaneous emission as a resource for entanglement in the photon number basis.
The ability to generate and manipulate light in pure quantum states is central to the development of quantum enhanced technologies, be it for optical quantum computing or for quantum secure communications. Recently, artificial atoms in the form of semiconductor quantum dots have emerged as an excellent platform to develop efficient components for optical quantum technologies. Using the tools of cavity quantum electrodynamics to harness the quantum light emission and to reduce the decoherence phenomena, single photon wavepackets with very high quantum purity can now be generated. This new generation of devices show unprecedented efficiency and allows scaling-up linear quantum optical technologies [3,4]. The high quality of the artificial atoms also allows to observe new phenomena, such as the generation of light pulses in a pure quantum superposition in the photon number basis [5], or to explore optical non-linearities at the single photon level [6] [1] N. Somaschi, et al. Nature Photonics, 10, 340 (2016) [2] P Senellart, G Solomon, A White, Nature Nanotechnology 12 (11), (2017) [3] C Antón, et al., Optica 6 (12), 1471-1477 (2019) [4] D. Istrati, arXiv 1912.04375 [5] J. C. Loredo, C. Antón, et., Nature Photonics 13 (11), 803 (2019) [6] L. De Santis, et al, Nature Nanotechnology 12, 663 (2017)
Quantum light is a key resource for the development of quantum-enhanced technologies such as secure communications, quantum networks, distributed quantum computing, metrology, etc. The development of these technologies requires light sources emitting single photons in a pure quantum state as well as efficient photon-photon gates. Such sources and gates can be obtained making use of the single-photon sensitivity of an atomic transition. We study artificial atoms in the form of semiconductor quantum dots to develop building blocks for optical quantum technologies. We use the tools of opto-electronics and nanotechnology to fabricate close to ideal atom-photon interfaces, where a single artificial atom interacts with a single mode of the optical field. We show that cavity quantum electrodynamics allows to largely isolate the artificial atoms from all sources of decoherence such as charge noise and crystal vibrations. We obtain bright solid-state sources of single photons with very high quantum purity, not only in the frequency basis, but for the first time also in the photon number basis. Finally, we have made progresses toward the development of efficient two-photon gates, with devices performing as nonlinear switches at the single-photon level. Some references: High-performances quantum light sources Somaschi et al., Nature Photonics 10, 340 (2016) Grange et al, Phys. Rev. Lett. 118, 253602 (2017) Senellart, Solomon and White, Nature Nanotechnology 12, 1026 (2017) J. C. Loredo, C. Anton, et. al, arXiv:1810.05170 Scaling-up optical quantum computing Loredo et al., Optica 3, 433 (2016) Loredo et al., Phys. Rev. Lett. 118, 130503 (2017) Toward efficient photon-photon gates Giesz et al., Nat. Comm 7, 11986 (2016) De Santis et al, Nature Nanotechnology 12, 663 (2017)
Photonic quantum technologies are based on controlled photon states. To generate these, quantum dots have emerged as excellent sources of single and entangled photons. In this Perspective, we briefly review the chronological development of quantum dots as photon sources, from their beginnings as quantum emitters in the early 2000s to the advanced photonic devices being developed today. We highlight the interplay between fundamental research and industrial aspects before discussing the photonic quantum technologies we expect to emerge in the near future.
Semiconductor quantum dots have emerged as excellent artificial atoms to both generate and manipulate quantum light. When embedded in cavities, they can generate single photons and entangled photons with unparalleled efficiency and high quantum purity. In this talk, I will discuss how such devices can be used to generate strings of many entangled photons. The method, leveraging the spin-selective optical transition in a charged quantum dot, leads to the generation of indistinguishable photons in linear cluster states or GHZ states at high rates, realizing an important milestone for scaling-up optical quantum technologies.
Semiconductor quantum dots (QDs) have emerged as a premier solid-state platform for the deterministic generation of nonclassical light, offering a compelling pathway toward scalable quantum photonic systems. While single-photon emission from QDs has reached a high level of maturity, the realization of high-fidelity entangled photon-pair sources remains an active and rapidly evolving frontier. In this review, we survey the recent progress in QD-based entangled photon sources, highlighting the conceptual evolution from the established biexciton-exciton cascade to the emerging paradigm of spontaneous two-photon emission. We further examine how advances in nanophotonic architectures and coherent control strategies are redefining fundamental performance limits, enabling concurrent improvements in source brightness, coherence, and entanglement fidelity. Finally, we discuss the key physical and technological challenges that must be addressed to bridge the gap between laboratory demonstrations and large-scale deployment. We conclude by outlining the future opportunities for integrating QD-based entangled photon sources into practical quantum communication, computation, and sensing platforms.
Semiconductor quantum dots (QDs) have emerged as a premier solid-state platform for the deterministic generation of nonclassical light, offering a compelling pathway toward scalable quantum photonic systems. While single-photon emission from QDs has reached a high level of maturity, the realization of high-fidelity entangled photon-pair sources remains an active and rapidly evolving frontier. In this review, we survey the recent progress in QD-based entangled photon sources, highlighting the conceptual evolution from the established biexciton–exciton cascade to the emerging paradigm of spontaneous two-photon emission. We further examine how advances in nanophotonic architectures and coherent control strategies are redefining fundamental performance limits, enabling concurrent improvements in source brightness, coherence, and entanglement fidelity. Finally, we discuss the key physical and technological challenges that must be addressed to bridge the gap between laboratory demonstrations and large-scale deployment. We conclude by outlining the future opportunities for integrating QD-based entangled photon sources into practical quantum communication, computation, and sensing platforms.