As a non-classical light source, single-photon source plays an essential role in the foundation of quantum physics and has been attracting a lot of attention of researchers over the world. Up to now, among different kinds of single-photon sources, single color centers in the diamond are very outstanding for the stable emission at room temperature as well as the spin controllability at ambient environment. Those color centers in the diamond with excellent properties are usually formed by impurity atoms and lattice vacancies. Nowadays, complex environments are necessary to the preparation of color centers generally. This restricts the research and applications of those color centers to a certain extent. Therefore, to develop efficient and high-precision fabrication methods of single color centers in the diamond at ambient environment is a need. On this condition, femtosecond (fs) laser process, a mature micro-nano processing technology, have been demonstrated to be a feasible, efficient, and fast production of the color centers in the diamond. This review discusses the state of the art in the preparation of single color centers in diamond and their applications in different areas.
As a non-classical light source, single-photon source plays an essential role in the foundation of quantum physics and has been attracting a lot of attention of researchers over the world. Up to now, among different kinds of single-photon sources, single color centers in the diamond are very outstanding for the stable emission at room temperature as well as the spin controllability at ambient environment. Those color centers in the diamond with excellent properties are usually formed by impurity atoms and lattice vacancies. Nowadays, complex environments are necessary to the preparation of color centers generally. This restricts the research and applications of those color centers to a certain extent. Therefore, to develop efficient and high-precision fabrication methods of single color centers in the diamond at ambient environment is a need. On this condition, femtosecond (fs) laser process, a mature micro-nano processing technology, have been demonstrated to be a feasible, efficient, and fast production of the color centers in the diamond. This review discusses the state of the art in the preparation of single color centers in diamond and their applications in different areas.
The silicon vacancy (SiV) color centers in diamond have significant potential in the fields of quantum information, nanophotonics, bioimaging and sensing, due to its good structural stability at room temperature, strong photostability, short luminescence lifetime, narrow zero-phonon line bandwidth, and avoidance of biological autofluorescence. They have attracted extensive attention and in-depth research from researchers. The applications of SiV color centers in the above areas require addressing key issues such as control over the number and charge state of SiV color centers in diamond, as well as improving the luminous efficiency. Therefore, this review summarizes some recent relevant research progress, including common methods for preparing SiV color centers, control over their luminescence intensity, preparation of SiV single-photon sources, and research on the control of SiV color center charge states. Based on these, an outlook is provided for the preparation and application of SiV color centers in diamond.
Color centres in diamond represent a very interesting system for realizing single photon emitters, even at room temperature, in particular are attracting an ever-growing interest in quantum optics, quantum information and quantum sensing, due to their appealing photo-physical properties combined with ease of access and manipulation in a solid state system characterized by high transparency and structural stability. Literally hundreds of optically active color centers can be created and controlled in the diamond matrix, to be employed either as bright and stable single-photon sources or individual spin systems with optical readout, with record performances even at room temperature. In concurrence with the remarkable results obtained at the state of the art on the exploitation of the unique properties of the negatively-charged nitrogen-vacancy complex (NV), new and appealing color centers are continuously being discovered and characterized. In the present contribution, the most recent results obtained by a collaboration among the Italian National Institutes of Metrologic Research (INRiM), the University of Torino and the Italian National Institutes of Nuclear Physics (INFN) will be overviewed and critically assessed in their future perspectives.
The past decade has seen great advances in developing color centers in diamond for sensing, quantum information processing, and tests of quantum foundations. Increasingly, the success of these applications as well as fundamental investigations of light-matter interaction depend on improved control of optical interactions with color centers -- from better fluorescence collection to efficient and precise coupling with confined single optical modes. Wide ranging research efforts have been undertaken to address these demands through advanced nanofabrication of diamond. This review will cover recent advances in diamond nano- and microphotonic structures for efficient light collection, color center to nanocavity coupling, hybrid integration of diamond devices with other material systems, and the wide range of fabrication methods that have enabled these complex photonic diamond systems.
The past two decades have seen great advances in developing color centers in diamond for sensing, quantum information processing, and tests of quantum foundations. Increasingly, the success of these applications as well as fundamental investigations of light–matter interaction depend on improved control of optical interactions with color centers—from better fluorescence collection to efficient and precise coupling with confined single optical modes. Wide ranging research efforts have been undertaken to address these demands through advanced nanofabrication of diamond. This review will cover recent advances in diamond nano- and microphotonic structures for efficient light collection, color center to nanocavity coupling, hybrid integration of diamond devices with other material systems, and the wide range of fabrication methods that have enabled these complex photonic diamond systems.
Abstract On the demand of single‐photon entangled light sources and high‐sensitivity probes in the fields of quantum information processing, weak magnetic field detection and biosensing, the nitrogen vacancy (NV) color center is very attractive and has been deeply and intensively studied, due to its convenience of spin initialization, operation, and optical readout combined with long coherence time in the ambient environment. Although the application prospect is promising, there are still some problems to be solved before fully exerting its characteristic performance, including enhancement of emission of NV centers in certain charge state (NV− or NV0), obtaining indistinguishable photons, and improving of collecting efficiency for the photons. Herein, the research progress in these issues is reviewed and commented on to help researchers grasp the current trends. In addition, the development of emerging color centers, such as germanium vacancy defects, and rare‐earth dopants, with great potential for various applications, are also briefly surveyed.
Optical sources that deliver single photons on demand play a key role in quantum cryptography and optical quantum computations. At present, color centers in wide-bandgap semiconductors, such as the nitrogen-vacancy (NV) and silicon-vacancy (SiV) centers in diamond, are considered to be the most promising candidates for practical quantum information applications owing to their unique emission properties at room temperature. However, for practical reasons, single-photon sources should be pumped electrically, which is required for integrability, scalability, and energy efficiency. However, diamond and related wide-bandgap semiconductor materials are at the interface between insulators and semiconductors, which makes electrical excitation of color centers very challenging. Here, we report on our progress in the understanding of single-photon electroluminescence of color centers in diamond, discuss different factors affecting the brightness of these emitter under electrical excitation, and study how to improve the performance of electrically- pumped single-photon sources based on color centers in diamond.