Solid-state quantum emitters, particularly epitaxial quantum dots (QDs), are one of the most promising platforms of quantum light sources to realize a compact quantum photonic architecture. Optimizing the performance of QDs for such purposes involves both source engineering and photonic control aspects. In this technical review, we examine a broad range of photonic techniques to control light–matter interaction in QDs, from an experimental viewpoint. Achieving full control over photonic degrees of freedom will transform quantum dots from laboratory to standardized building blocks in photonic quantum systems.
Solid-state quantum emitters, particularly epitaxial quantum dots (QDs), are one of the most promising platforms of quantum light sources to realize a compact quantum photonic architecture. Optimizing the performance of QDs for such purposes involves both source engineering and photonic control aspects. In this technical review, we examine a broad range of photonic techniques to control light–matter interaction in QDs, from an experimental viewpoint. Achieving full control over photonic degrees of freedom will transform quantum dots from laboratory to standardized building blocks in photonic quantum systems.
Semiconductor nanostructures such as quantum dots (QDs) have offered unique opportunities to investigate quantum optical effects in solid-state systems. These include quantum interference, Rabi oscillations, as well as photon antibunching, and were previously observable only in isolated atoms or ions. In addition, QDs can be integrated into optical microcavities, making them attractive for applications in quantum information processing and high efficiency quantum light sources. Despite much progress towards these goals, one area that was little explored is coherent control of such solid-state quantum emitters in cavities. The main technical hurdle lies in overcoming the laser background scattering. By using a sample structure in which QDs are embedded in a planar Fabry-Perot cavity and by using an orthogonal excitation geometry, we have achieved a nearly complete elimination of laser background scattering. This in turn allows us to show resonantly controlled light emission of quantum dots in the cavity including (a) Rabi flopping using pulse control, (b) direct observation of Mollow triplets in the frequency domain, and (c) simultaneously measured first-order and second order photon-photon correlations.
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.
The preparation and control of quantum states lie at the heart of quantum information science (QIS). Recent advances in solid-state quantum emitters (QEs) and nanophotonics have transformed the landscape of quantum photonic technologies, enabling scalable generation of quantum states of light and matter. A new frontier in solid-state quantum photonics is the engineering of many-body interactions between QEs and photons to achieve robust coherence and controllable many-body entanglement. These entangled states, including photonic graph and cluster states, superradiant emission, and emergent quantum phases, are promising for quantum computation, sensing, and simulation. However, intrinsic inhomogeneities and decoherence in solid-state platforms pose significant challenges to realize such complex entangled states. This review provides an overview of the fundamental many-body interactions and dynamics at the light-matter interfaces of solid-state QEs, and discusses recent advances in mitigating decoherence and harnessing robust many-body coherence.
Epitaxial quantum dots formed by III-V compound semiconductors are excellent sources of nonclassical photons, creating single photons and entangled multi-photon states on demand.Their semiconductor nature allows for a straightforward combination with mature integrated photonic technologies, leading to novel functional devices at the single-photon level.Integrating a quantum dot into a carefully engineered photonic cavity enables control of the radiative decay rate using the Purcell effect and the realization of photon-photon nonlinear gates.In this review, we introduce the basis of epitaxial quantum dots and discuss their applications as non-classical light sources.We highlight two interfaces-one between flying photons and the quantum-dot dipole, and the other between the photons and the spin.We summarize the recent development of integrated photonics and reconfigurable devices that have been combined with quantum dots or are suitable for hybrid integration.Finally, we provide an outlook of employing quantum-dot platforms for practical applications in large-scale quantum computation and the quantum Internet.
The preparation and control of quantum states lie at the heart of quantum information science (QIS). Recent advances in solid-state quantum emitters (QEs) and nanophotonics have transformed the landscape of quantum photonic technologies, enabling scalable generation of quantum states of light and matter. A new frontier in solid-state quantum photonics is the engineering of many-body interactions between QEs and photons to achieve robust coherence and controllable many-body entanglement. These entangled states, including photonic graph and cluster states, superradiant emission, and emergent quantum phases, are promising for quantum computation, sensing, and simulation. However, intrinsic inhomogeneities and decoherence in solid-state platforms pose significant challenges to realize such complex entangled states. This review provides an overview of the fundamental many-body interactions and dynamics at the light-matter interfaces of solid-state QEs, and discusses recent advances in mitigating decoherence and harnessing robust many-body coherence.