Abstract In today’s rapidly evolving quantum landscape, the generation and manipulation of quantum light not only represent fundamental challenges but also herald unprecedented opportunities in communication, computing, sensing, and imaging. This special issue brings together a collection of contributions that span the entire journey, from the creation of quantum light using novel materials and emitters to its seamless integration into photonic architectures and eventual deployment in advanced quantum applications. This special issue, “ Quantum Light: Creation, Integration, and Applications ,” features a collection of three review articles, five perspectives, and 23 original research papers, highlighting both the timeliness of the topic and the remarkable breadth and richness of ongoing advancements in the field.
Abstract In today’s rapidly evolving quantum landscape, the generation and manipulation of quantum light not only represent fundamental challenges but also herald unprecedented opportunities in communication, computing, sensing, and imaging. This special issue brings together a collection of contributions that span the entire journey, from the creation of quantum light using novel materials and emitters to its seamless integration into photonic architectures and eventual deployment in advanced quantum applications. This special issue, “ Quantum Light: Creation, Integration, and Applications ,” features a collection of three review articles, five perspectives, and 23 original research papers, highlighting both the timeliness of the topic and the remarkable breadth and richness of ongoing advancements in the field.
Photons are very promising resources for the whole field of quantum information processing. Bulk optics are currently not suitable for the realization of complex quantum optical schemes due to several drawbacks. The ongoing miniaturization of photonic structures due to the availability of sophisticated nanofabrication has provided huge opportunities for physical research of novel phenomena in nanophotonic systems and quantum technological applications. These include quantum information processing such as quantum computing, quantum communication, quantum metrology, and quantum sensing. Quantum communication is already quite advanced with several quantum key distribution (QKD) systems commercially available offering absolute security. Photonic quantum technologies are enabling breakthroughs in experimental tests of quantum physics and are close to practical applications of quantum technologies in imaging, secure communications, ultrasensitive metrology and quantum computing. There are several advantages to encoding a quantum bit onto a photon: the preparation and manipulation of single photons is easy, and the photonic qubit is a natural candidate for quantum imaging and communications. Furthermore, the qubit can be encoded in various degrees of freedom such as on the position, phase, time-bin, energy, angular momentum, polarization of the photon—or a combination of these. This flexibility leads to enormous opportunities for scientific exploration and in practical applications. This special issue on “Photonic Quantum Technologies” presents selected papers on photonic quantum systems from leading groups in the world. The articles represent a flavor of the cutting-edge research that is going on in this area. The studied material systems range from molecules to semiconductor quantum emitters. A major challenge is the design of telecom photon emitters with high efficiency, good yield, spectral purity, stability and the possibility of mass manufacture. We believe that this Special Issue will provide an overview of recent exciting developments in the field of photonic quantum technologies, serving to keep researchers up-to-date with the latest progress and spurring on new concepts in this field.
The field of quantum sensing leverages quantum mechanical resources such as superposition, entanglement, and squeezing to surpass classical limits in measurement precision and enable new sensing modalities. This Special Topic Collection in Applied Physics Reviews brings together recent advances spanning theory, materials, device engineering, and applications of quantum sensors. Contributions cover a wide range of platforms, including atomic, solid-state, optomechanics, and photonics, highlighting both fundamental science and emerging technologies. The collection illustrates the transition of quantum sensing from foundational concepts toward scalable technologies and broadens its impact across physics, engineering, and applied sciences.
The realization of scalable, real world devices in quantum technologies requires myriad new approaches and hardware components. Integrated photonics play a crucial role in many applications in quantum information and quantum sensing, enabling the realization of key components such as new light sources, waveguides, resonators, and detectors. The field of integrated quantum photonics is booming, and an increasing number of research groups are contributing to the accelerating efforts to study fundamental and technological challenges at the intersection of quantum optics, nanophotonics, and hybrid integrated devices. This Special Topic Collection is dedicated to highlighting important progress in the field of integrated quantum photonics and presenting new cutting-edge results, both experimental and theoretical, toward the common goal of exploring quantum photonic phenomena.
Single photons and individual quantum systems are at the heart of recent developments in quantum technologies and are about to enable a variety of novel applications in sensing, communication, and computing. Photonic devices are the key to control interactions between quantum systems and light as well as to simultaneously engineer the properties of photons. For scalable quantum technologies, the employed quantum systems are solid-state based, thus placing the field of quantum photonics at the intersection of physics, nanotechnology, and material sciences. This special issue features 14 contributions and addresses recent advances in several material platforms.
Light has provided both fundamental phenomenology and enabling technology for scientific discovery for many years, and today it continues to play a central role in fundamental explorations and innovative applications. The ability to manipulate light beams and pulses with the quantum degrees of freedom of optical radiation will add to those advances. The future of quantum optics, which encompasses both the generation and manipulation of nonclassical radiation, as well as its interaction with matter, lies in the rich variety of quantum states that is now becoming feasible to prepare, together with the numerous applications in sensing, imaging, metrology, communications, and information processing that such states enable.
In recent years, the field of quantum nanophotonics has been thriving with an intense interest in the development of new theories, devices, and applications for specific uses.This special issue on "Quantum nanophotonics" highlights some recent developments in this topic through reviews, perspectives, and research papers.This issue contains review and perspective articles that provide a comprehensive overview of cutting-edge topics.Chang and Zwiller [1] review the recent progresses in integrated quantum photonics using nanowires, focusing on integrated emitters, detectors, and fabrication methods.This review also presents the applications for quantum information processing and sensing based on nanowires.Gali [2] summarizes the ab initio theory to fully understand solid-state qubits, which are an essential component in the quantum photonic device.This computational method has been applied to the calculation of excited states, photo-ionization threshold, optical excitation spectra, effective mass states, and spin dynamics.This approach could give insights beyond conventional density functional theory that cannot fully capture the characteristics of excited states.Biotechnologies are being used in a variety of quantum optics and photonics or vice versa.DNA nanotechnology, using the information of DNA to design and manufacture artificial nucleic acid structures for technological uses, has been utilized in the field of quantum emitters.Exotic traits of DNA enable the grabbing of quantum emitters and steering of their directors at the molecular level of resolution.The relevant studies were extensively reviewed by Cho et al. [3].Reversely, the understanding of light-matter interaction in quantum optics provides a hint to investigate chemical and biological processes.Kim et al. [4] present a review of plexcitonic and vibro-polaritonic strong coupling based on light-matter interaction with optical resonators.The authors introduce from fundamentals of strong coupling, configuration and characteristics of plexcitons, and applications for chemistry and biological detection.Kim et al. [5] discuss that nanophotonic resonance engineering can make the near-unity readout fidelity necessary for improving the sensitivity of NV quantum sensing.The perspective gives insight into the background of NV quantum sensing, applications of resonant structures, and the remaining challenges for practical sensing.Zheng and Kim [6] address the degradation mechanisms of perovskite-based light-emitting diodes.The degradation can potentially occur in external and internal processes, leading to distinct effects on performance and stability.Various research articles on quantum nanophotonics are included.There is growing interest in optimizing the single photon emitter (SPE) that can be integrated into the photonic circuit and enable practical application.Azzam et al. [7] demonstrate the Purcell enhancement of WSe 2 SPE using a dielectric cavity.The dielectric cavity imposes an oriented strain profile on the WSe 2 , which can make the polarization state of the SPE selectively controlled.Xu et al. [8] report a high-purity SPE based on nanodiamonds (NDs) with negatively charged silicon vacancy (SiV -) centers using an ion implantation method.They successfully prevent SiV -emitters from