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Single photon emitters (SPEs) hosted in hexagonal boron nitride (hBN) are essential elementary building blocks for enabling future on-chip quantum photonic technologies that operate at room temperature. However, fundamental challenges, such as managing non-radiative decay, competing incoherent processes, as well as engineering difficulties in achieving deterministic placement and scaling of the emitters, limit their full potential. In this work, we experimentally demonstrate large-area arrays of plasmonic nanoresonators for Purcell-induced site-controlled SPEs by engineering emitter-cavity coupling and enhancing radiative emission at room temperature. The plasmonic nanoresonator architecture consists of gold-coated silicon pillars capped with an alumina spacer layer, enabling a 10-fold local field enhancement in the emission band of native hBN defects. Confocal photoluminescence and second-order autocorrelation measurements show bright SPEs with sub-30 meV bandwidth and a saturated emission rate of more than 3.8 million counts per second. We measure a Purcell factor of 4.9, enabling average SPE lifetimes of 480 ps, a five-fold reduction as compared to emission from gold-free devices, along with an overall SPE yield of 21%. Density functional theory calculations further reveal the beneficial role of an alumina spacer between defected hBN and gold, as an insulating layer can mitigate the electronic broadening of emission from defects proximal to gold. Our results offer arrays of bright, heterogeneously integrated quantum light sources, paving the way for robust and scalable quantum information systems., Comment: 41 pages, 18 figures, supplementary information

The integration of solid-state single-photon sources with foundry-compatible photonic platforms is crucial for practical and scalable quantum photonic applications. This study investigates aluminum nitride (AlN) as a material with properties highly suitable for integrated on-chip photonics specifically due to AlN capacity to host defect-center related single-photon emitters. We conduct a comprehensive study of the creation and photophysical properties of single-photon emitters in AlN utilizing Zirconium (Zr) and Krypton (Kr) heavy ion implantation and thermal annealing techniques. Guided by theoretical predictions, we assess the potential of Zr ions to create optically addressable spin-defects and employ Kr ions as an alternative approach that targets lattice defects without inducing chemical doping effects. With the 532 nm excitation wavelength, we found that single-photon emitters induced by ion implantation are primarily associated with vacancy-type defects in the AlN lattice for both Zr and Kr ions. The emitter density increases with the ion fluence, and there is an optimal value for the high density of emitters with low AlN background fluorescence. Additionally, under shorter excitation wavelength of 405 nm, Zr-implanted AlN exhibits isolated point-like emitters, which can be related to Zr-based defect complexes. This study provides important insights into the formation and properties of single-photon emitters in aluminum nitride induced by heavy ion implantation, contributing to the advancement of the aluminum nitride platform for on-chip quantum photonic applications., Comment: The following article has been submitted to APL Quantum. After it is published, it will be found at AIP Publishing/APL Quantum

A robust process for fabricating intrinsic single-photon emitters in silicon nitride has been recently established. These emitters show promise for quantum applications due to room-temperature operation and monolithic integration with the technologically mature silicon nitride photonics platform. Here, the fundamental photophysical properties of these emitters are probed through measurements of optical transition wavelengths, linewidths, and photon antibunching as a function of temperature from 4.2K to 300K. Important insight into the potential for lifetime-limited linewidths is provided through measurements of inhomogeneous and temperature-dependent homogeneous broadening of the zero-phonon lines. At 4.2K, spectral diffusion was found to be the main broadening mechanism, while time-resolved spectroscopy measurements revealed homogeneously broadened zero-phonon lines with instrument-limited linewidths., Comment: 21 pages, 10 figures

The recent discovery of room temperature intrinsic single-photon emitters in silicon nitride (SiN) provides the unique opportunity for seamless monolithic integration of quantum light sources with the well-established SiN photonic platform. In this work, we develop a novel approach to realize planar waveguides made of low-autofluorescing SiN with intrinsic quantum emitters and demonstrate the single-photon emission coupling into the waveguide mode. The observed emission coupling from these emitters is found to be in line with numerical simulations. The coupling of the single-photon emission to a waveguide mode is confirmed by second-order autocorrelation measurements of light outcoupled off the photonic chip by grating couplers. Fitting the second-order autocorrelation histogram yields $g^{(2)}(0)=0.35\pm0.12$ without spectral filtering or background correction with an outcoupled photon rate of $10^4$ counts per second. This demonstrates the first successful coupling of photons from intrinsic single-photon emitters in SiN to monolithically integrated waveguides made of the same material. The results of our work pave the way toward the realization of scalable, technology-ready quantum photonic integrated circuitry efficiently interfaced with solid-state quantum emitters., Comment: 10 pages, 5 figures

Single-photon emitters are essential for enabling several emerging applications in quantum information technology, quantum sensing and quantum communication. Scalable photonic platforms capable of hosting intrinsic or directly embedded sources of single-photon emission are of particular interest for the realization of integrated quantum photonic circuits. Here, we report on the first-time observation of room-temperature single-photon emitters in silicon nitride (SiN) films grown on silicon dioxide substrates. As SiN has recently emerged as one of the most promising materials for integrated quantum photonics, the proposed platform is suitable for scalable fabrication of quantum on-chip devices. Photophysical analysis reveals bright (>$10^5$ counts/s), stable, linearly polarized, and pure quantum emitters in SiN films with the value of the second-order autocorrelation function at zero time delay $g^{(2)}(0)$ below 0.2 at room temperatures. The emission is suggested to originate from a specific defect center in silicon nitride due to the narrow wavelength distribution of the observed luminescence peak. Single-photon emitters in silicon nitride have the potential to enable direct, scalable and low-loss integration of quantum light sources with the well-established photonic on-chip platform., Comment: 15 pages, 4 figures, and Supplementary Information