A new device consisting of a semiconductor ring produces pairs of entangled photons that could be used in a photonic quantum processor. By Michael SchirberQ uantum light sources produce entangled pairs of photons that can be used in quantum computing and cryptography.A new experiment has demonstrated a quantum light source made from the semiconductor gallium nitride.This material provides a versatile platform for device fabrication, having previously been used for on-chip lasers, detectors, and waveguides.Combined with these other optical components, the new quantum light source opens up the potential to construct a complex quantum circuit, such as a photonic quantum processor, on a single chip.Quantum optics is a rapidly advancing field, with many experiments using photons to carry quantum information and perform quantum computations.However, for optical systems
A new device consisting of a semiconductor ring produces pairs of entangled photons that could be used in a photonic quantum processor. By Michael SchirberQ uantum light sources produce entangled pairs of photons that can be used in quantum computing and cryptography.A new experiment has demonstrated a quantum light source made from the semiconductor gallium nitride.This material provides a versatile platform for device fabrication, having previously been used for on-chip lasers, detectors, and waveguides.Combined with these other optical components, the new quantum light source opens up the potential to construct a complex quantum circuit, such as a photonic quantum processor, on a single chip.Quantum optics is a rapidly advancing field, with many experiments using photons to carry quantum information and perform quantum computations.However, for optical systems
Integrated quantum light source is increasingly desirable in large-scale quantum information processing.~Despite recent remarkable advances, new material platform is constantly being explored for the fully on-chip integration of quantum light generation, active and passive manipulation, and detection. Here, for the first time, we demonstrate a gallium nitride (GaN) microring based quantum light generation in the telecom C-band, which has potential towards the monolithic integration of quantum light source.~In our demonstration, the GaN microring has a free spectral range of 330 GHz and a near-zero anomalous dispersion region of over 100 nm. The generation of energy-time entangled photon pair is demonstrated with a typical raw two-photon interference visibility of 95.5$\pm$6.5%, which is further configured to generate heralded single photon with a typical heralded second-order auto-correlation gH(2)(0) of 0.045$\pm$0.001. Our results pave the way for developing chip-scale quantum photonic circuit.
An integrated quantum light source is increasingly desirable in large-scale quantum information processing. Despite recent remarkable advances, a new material platform is constantly being explored for the fully on-chip integration of quantum light generation, active and passive manipulation, and detection. Here, for the first time, we demonstrate a gallium nitride (GaN) microring based quantum light generation in the telecom C-band, which has potential toward the monolithic integration of quantum light source. In our demonstration, the GaN microring has a free spectral range of 330 GHz and a near-zero anomalous dispersion region of over 100 nm. The generation of energy-time entangled photon pair is demonstrated with a typical raw two-photon interference visibility of 95.5±6.5%, which is further configured to generate a heralded single photon with a typical heralded second-order autocorrelation g_{H}^{(2)}(0) of 0.045±0.001. Our results pave the way for developing a chip-scale quantum photonic circuit.
Optical chips for quantum photonics are cutting-edge technology, merging photonics and quantum mechanics to manipulate light at the quantum level. These chips are crucial for advancing quantum computing, secure communication, and precision sensing by integrating photonic components such as waveguides, beam splitters, and detectors to manipulate single photons, the fundamental carriers of quantum information. Key advancements in optical chips include low-loss waveguides, efficient single-photon sources, and high-fidelity quantum gates, all essential for scalable quantum circuits. Integrating these circuits on a chip offers significant advantages in miniaturization, stability, and reproducibility over traditional bulk optics setups. Recent breakthroughs in materials science and nanofabrication have propelled the field forward, enabling the production of chips with higher precision and lower defect rates. Silicon photonics, in particular, has become a prominent platform due to its compatibility with existing semiconductor manufacturing processes, facilitating the integration of quantum photonic circuits with classical electronic systems. Here, we share our vision of the future of optical chips for quantum photonics, which hold promise for various applications. In quantum computing, they enable the development of compact and scalable quantum processors. In communication, they provide the foundation for ultra-secure quantum networks through quantum key distribution. In sensing, they allow for high-precision measurements that surpass classical limits. As research progresses, optical chips are expected to play a critical role in realizing the full potential of quantum technologies.
A key element in the quickly developing science of photonic quantum information processing is quantum light sources. These sources are crucial for applications in quantum computing, quantum cryptography, and quantum communication because they can produce both single photons and entangled photon pairs. The efficiency, scalability, and performance of quantum light sources have been greatly enhanced by recent developments in four-wave mixing, spontaneous parametric down-conversion, and quantum dot technology. the most recent advancements in constructed quantum light sources, emphasizing how they help solve important problems including coherence, indistinguishability, and integration with current photonic systems. We explore how these sources can improve the fidelity and reliability of quantum circuits and how they could transform fault-tolerant quantum computing and secure communication networks in the future. In order to further the practical application of quantum technologies, the study also suggests potential paths for combining quantum light sources with scalable photonic systems.
Quantum-photonic chips, which integrate quantum light sources alongside active and passive optical elements, as well as single-photon detectors, show great potential for photonic quantum information processing and quantum technology. Mature semiconductor nanofabrication processes allow for scaling such photonic integrated circuits to on-chip networks of increasing complexity. Second-order nonlinear materials are the method of choice for generating photonic quantum states in the overwhelming majority of linear optic experiments using bulk components, but integration with waveguide circuitry on a nanophotonic chip proved to be challenging. Here, we demonstrate such an on-chip parametric down-conversion source of photon pairs based on second-order nonlinearity in an aluminum-nitride microring resonator. We show the potential of our source for quantum information processing by measuring the high visibility anti-bunching of heralded single photons with nearly ideal state purity. Our down-conversion source yields measured coincidence rates of 80 Hz, which implies MHz generation rates of correlated photon pairs. Low noise performance is demonstrated by measuring high coincidence-to-accidental ratios. The generated photon pairs are spectrally far separated from the pump field, providing great potential for realizing sufficient on-chip filtering and monolithic integration of quantum light sources, waveguide circuits and single-photon detectors. A chip-based source of photon pairs for applications in quantum information processing has been built by a team of scientists in the US. Xiang Guo and co-workers from Yale University built the quantum light source from an aluminum nitride microring resonator. The strong second-order nonlinearity of the aluminum nitride yields efficient parametric down-conversion. This allows 775-nm-wavelength pump photons to be converted into a pair of entangled photons in the telecommunications window of 1550 nm. Tests indicated that the heralded photons generated by the microring source are anti-bunched and have high visibility and a high purity of state, indicating that they are highly suitable for use in quantum optics experiments. In principle, the on-chip source is compatible with megahertz generation rates and large-scale manufacture of integrated optical circuits.
Multi-wavelength quantum light sources, especially at telecom band, are extremely desired in quantum information technology. Despite recent impressive advances, such a quantum light source with high quality remains challenging. Here we demonstrate a multi-wavelength quantum light source using a silicon nitride micro-ring with a free spectral range of 200 GHz. The generation of eight pairs of correlated photons is ensured in a wavelength range of 25.6 nm. With device optimization and noise-rejecting filters, our source enables the generation of heralded single-photons - at a rate of 62 kHz with gh(2)(0)=0.014±0.001, and the generation of energy-time entangled photons - with a visibility of 99.39±0.45% in the Franson interferometer. These results, at room temperature and telecom wavelength, in a CMOS compatible platform, represent an important step towards integrated quantum light devices for the quantum networks.