Abstract Deterministically integrating single solid‐state quantum emitters with photonic nanostructures serves as a key enabling resource in the context of photonic quantum technology. Due to the random spatial location of many widely‐used solid‐state quantum emitters, a number of positioning approaches for locating the quantum emitters before nanofabrication have been explored in the last decade. Here, the working principles of several nanoscale positioning methods and the most recent progress in this field, covering techniques including atomic force microscopy, scanning electron microscopy, confocal microscopy with in situ lithography, and wide‐field fluorescence imaging are reviewed. A selection of representative device demonstrations with high‐performance is presented, including high‐quality single‐photon sources, bright entangled‐photon pairs, strongly‐coupled cavity QED systems, and other emerging applications. The challenges in applying positioning techniques to different material systems and opportunities for using these approaches for realizing large‐scale quantum photonic devices are discussed.
Abstract Deterministically integrating single solid‐state quantum emitters with photonic nanostructures serves as a key enabling resource in the context of photonic quantum technology. Due to the random spatial location of many widely‐used solid‐state quantum emitters, a number of positioning approaches for locating the quantum emitters before nanofabrication have been explored in the last decade. Here, the working principles of several nanoscale positioning methods and the most recent progress in this field, covering techniques including atomic force microscopy, scanning electron microscopy, confocal microscopy with in situ lithography, and wide‐field fluorescence imaging are reviewed. A selection of representative device demonstrations with high‐performance is presented, including high‐quality single‐photon sources, bright entangled‐photon pairs, strongly‐coupled cavity QED systems, and other emerging applications. The challenges in applying positioning techniques to different material systems and opportunities for using these approaches for realizing large‐scale quantum photonic devices are discussed.
Deterministically integrating single solid-state quantum emitters with photonic nanostructures serves as a key enabling resource in the context of photonic quantum technology. Due to the random spatial location of many widely-used solid-state quantum emitters, a number of positoning approaches for locating the quantum emitters before nanofabrication have been explored in the last decade. Here, we review the working principles of several nanoscale positioning methods and the most recent progress in this field, covering techniques including atomic force microscopy, scanning electron microscopy, confocal microscopy with \textit{in situ} lithography, and wide-field fluorescence imaging. A selection of representative device demonstrations with high-performance is presented, including high-quality single-photon sources, bright entangled-photon pairs, strongly-coupled cavity QED systems, and other emerging applications. The challenges in applying positioning techniques to different material systems and opportunities for using these approaches for realizing large-scale quantum photonic devices are discussed.
ABSTRACT Integrated quantum photonics is rapidly emerging as a transformative platform for realizing scalable, chip‐based quantum technologies, from secure communication to advanced sensing and computing. At the heart of this revolution are solid‐state quantum emitters: atom‐like light sources embedded in a variety of host materials that enable single‐photon generation, quantum interference, and spin–photon coupling. We begin by discussing quantum emitters across bulk crystals, van der Waals materials, and chemically synthesized nanostructures, highlighting their performance trade‐offs and integration potential. We then examine nanophotonic cavities that enhance the light‐matter interaction, from photonic crystals to metasurfaces and Moiré resonators. Next, we discuss fabrication techniques with sub‐10 nm precision, including material‐specific etching strategies and hybrid integration schemes. Finally, we address emerging approaches for deterministic placement, cavity tuning, and on‐chip scalability. By bringing together insights from materials science, nanofabrication, and quantum optics, this Review provides a comprehensive perspective on the design and integration of high‐performance quantum emitters for scalable photonic platforms.
The controlled generation of non-classical states of light is a challenging task at the heart of quantum optics. Aside from the mere spirit of science, the related research is strongly driven by applications in photonic quantum technologies, including the fields of quantum communication, quantum computation, and quantum metrology. In this context, the realization of integrated solid-state-based quantum-light sources is of particular interest, due to the prospects for scalability and device integration. This topical review focuses on solid-state quantum-light sources which are fabricated in a deterministic fashion. In this framework we cover quantum emitters represented by semiconductor quantum dots, colour centres in diamond, and defect-/strain-centres in two-dimensional materials. First, we introduce the topic of quantum-light sources and non-classical light generation for applications in photonic quantum technologies, motivating the need for the development of scalable device technologies to push the field towards real-world applications. In the second part, we summarize material systems hosting quantum emitters in the solid-state. The third part reviews deterministic fabrication techniques and comparatively discusses their advantages and disadvantages. The techniques are classified in bottom-up approaches, exploiting the site-controlled positioning of the quantum emitters themselves, and top-down approaches, allowing for the precise alignment of photonic microstructures to pre-selected quantum emitters. Special emphasis is put on the progress achieved in the development of in situ techniques, which significantly pushed the performance of quantum-light sources towards applications. Additionally, we discuss hybrid approaches, exploiting pick-and-place techniques or wafer-bonding. The fourth part presents state-of-the-art quantum-dot quantum-light sources based on the fabrication techniques presented in the previous sections, which feature engineered functionality and enhanced photon collection efficiency. The article closes by highlighting recent applications of deterministic solid-state-based quantum-light sources in the fields of quantum communication, quantum computing, and quantum metrology, and by discussing future perspectives in the field of solid-state quantum-light sources.
Single quantum emitters are critical components for many future quantum information technologies. Novel active material systems have been developed and transitioned into engineering efforts at nanoscale. Here, we review recent progress of diverse quantum emitters and their optical properties, including fluorescent point defect in bulk and single nanocrystal, two-dimensional materials, and quantum dots (QDs). Remarkable progress has also been made in controlling spontaneous emission by utilizing the local density of optical states in dielectric photonic nanostructures. We focus on the enhanced light–matter interaction between the emitter and cavity, enabling the realization of efficient and fast single photon sources.
Abstract A key obstacle for all quantum information science and engineering platforms is their lack of scalability. The discovery of emergent quantum phenomena and their applications in active photonic quantum technologies have been dominated by work with single atoms, self‐assembled quantum dots, or single solid‐state defects. Unfortunately, scaling these systems to many quantum nodes remains a significant challenge. Solution‐processed quantum materials are uniquely positioned to address this challenge, but the quantum properties of these materials have remained generally inferior to those of solid‐state emitters or atoms. Additionally, systematic integration of solution‐processed materials with dielectric nanophotonic structures has been rare compared to other solid‐state systems. Recent progress in synthesis processes and nanophotonic engineering, however, has demonstrated promising results, including long coherence times of emitted single photons and deterministic integration of emitters with dielectric nano‐cavities. In this review article, these recent experiments using solution‐processed quantum materials and dielectric nanophotonic structures are discussed. The progress in non‐classical light state generation, exciton‐polaritonics for quantum simulation, and spin‐physics in these materials is discussed and an outlook for this emerging research field is provided.