Optical clocks are amazingly stable frequency standards, which would remain accurate to within one second over the age of the universe. Bringing these clocks from the lab to the market offers great opportunities for telecommunications, navigation, sensing, and science, but no commercial optical clock exists. Europe's world leading optical clock technology within academia and national metrology institutes combined with its strong photonics industry, provide us with a golden opportunity to take a leading position in this strategic technology. With AQuRA we want to seize this opportunity and build up a sovereign, efficient industrial capability able to build the world’s most advanced quantum clocks. We will deliver the first industry-built, rugged and transportable optical clock with an accuracy that approaches the best laboratory clocks. Our work is based on the experience that many of us gained by building an optical clock with industry during the Quantum Flagship project iqClock (2018-2022). In AQuRA industry takes the lead and will deliver a 20x more accurate clock in a 3x smaller volume at TRL 7. This will be possible by combining our industry partners’ experience in rugged photonics products with the know-how of our world-leading academic and national metrology institute partners. We will build, strengthen and diversify the European supply chain of optical clock components, filling critical gaps in the supply chain, and thereby establish a sovereign, competitive industry for optical clocks. In particular we will develop the rugged laser sources, miniaturized optical interface circuits, and the atom source needed for an optical clock, all of which will also become products on their own. Partner Menlo Systems will integrate these components with their ultrastable laser system into the AQuRA optical clock. We will accelerate market uptake by demonstrating our clock's usefulness to applications in telecom, geodesy and metrology, and by engaging with end users.

Randomness is a resource that enables applications such as efficient probabilistic algorithms, numerical integration, simulation, and optimization. In the last few years it was realized that quantum devices can generate probability distributions that are inaccessible with classical means. Hybrid Quantum Computational models combine classical processing with these quantum sampling machines to obtain computational advantage in some tasks. Moreover, NISQ (Noisy, Intermediate-Scale Quantum) technology may suffice to obtain this advantage in the near term, long before we can build large-scale, universal quantum computers. PHOQUSING aims to implement PHOtonic Quantum SamplING machines based on large, reconfigurable interferometers with active feedback, and state-of-the-art photon sources based both on quantum dots and parametric down-conversion. We will overview the different architectures enabling the generation of these hard-to-sample distributions using integrated photonics, optimizing the designs and studying t

The rapidly growing global adaptation of digital technologies has brought an exponential increase in data and computing power consumption, and conventional supercomputers are now reaching their limit in terms of power and energy efficiency. Quantum computers have garnered attention as a way to overcome the struggles of classical computers. Technological progress is happening fast, but the so-called quantum advantage results reported have no meaningful real-world tasks yet, and severe scaling problems remain. An alternative strategy of encoding information in high-dimensional spaces (using quDits rather than qubits) is extremely promising for enhancing computational capacity, accuracy, speed, and noise robustness. However, this approach is still in its infancy. QuGANTIC proposes a science-towards-technology breakthrough in scalable data loading and learning with quantum processors, based on a novel concept of hybrid integration on a single photonic integrated chip (PIC). Our innovative target is the first quantum computer using quDits generated by quantum frequency combs with the potential to execute operations in a reduced number of steps and provide the first scalable PIC quantum computer. Learning distributions of data and generating artificial samples is a formidable task for classical computers, and we will use our novel quDit PIC platform to demonstrate that so-called quantum Generative Adversarial Networks can solve this task far better than classical systems. Our goal will make an unprecedented impact on economy, science and society, as it will predict the behavior of globally critical areas such as energy distribution, weather phenomena, risk assessments and epidemic spreads, by processing vast data sets with a drastic reduction of computational overheads. Our processors have a credible path to market, and QuGANTIC has the right hardware and software Partners to realize this enormous potential.

Quantum technology holds the promise of enabling next generation computing, communications and sensing systems. However, the size, cost and scalability of current devices prevents them from reaching their full potential. Photonics is one of the key enabling technologies for quantum technology. In particular, photonics integrated circuits (PICs) with their wafer-level manufacturing based on microfabrication technologies can provide the reduction in size and cost and enable next generation scalable quantum technologies. To fully achieve this goal, an universal PIC technology that can serve most quantum applications is needed. In QU-PIC, we selected the Al2O3 integrated photonics platform as backbone technology for the development of quantum PICs thanks to its excellent low propagation loss performance and wide operating spectral region from the ultraviolet (200 nm) until the mid-infrared. A large range of PIC building blocks is developed in QU-PIC, focusing on areas where materials or integration technologies are not yet available. Several light sources, including multiwavelength tunable lasers with operation at 399 nm, 411 nm and 935 nm on the PIC, UVC external cavity lasers emitting at 280 nm, sources of squeezed photons, single photon detectors, programmable ASICs and the required packaging and assembly technologies will be investigated. An open PDK will group all the developed quantum building blocks to accelerate innovation from the initial idea to an actually manufactured system. Two application demonstrators will be implemented using the developed building blocks, namely a source of GKP states for quantum processing and an atomic clock based on Yb+ ions for quantum sensing. It is the ambition of QU-PIC to secure a full European supply chain to establish Europe’s Sovereignty and manufacturing capabilities in photonics integrated circuits for quantum.

Over the years sensors expanded their field of use from scientific exploration to consumer electronics, and their market evolved accordingly. Quantum technologies are expected to further push sensor’s performances, unlocking even more application domains, exploiting non-classical correlation of light and matter to extract the relevant information beyond the limit dictated by classical noise processes, improving performances such as sensitivity, specificity and uncertainty. The ability to produce, control and measure quantum states in transportable devices is the key to extend the sensors’ operating environment, lifetime, power consumption and costs. QUANTIFY fits perfectly this vision and the goal of Demonstrating quantum sensing beyond classical capabilities for real-world applications, in the Strategic Research Agenda of the Quantum Flagship Program. QUANTIFY objective consists in bringing photonic quantum enhanced sensors at the next level of integration developing the essential building blocks and novel quantum-enhanced techniques for future chip scale optical clocks, optically pumped magnetometers and optomechanical temperature sensors. QUANTIFY leverages different photonic platforms combined by a novel hybrid integration technique to bring the key optical and optomechanical functionalities on a single chip. To increase the clock and magnetometer performances, we introduce a photonic integrated squeezed light source, also becoming an important step for realizing a universal quantum computer based on photonics. Finally, we demonstrate a novel absolute temperature sensor with an extended detection range, from cryogenic to room temperature leveraging a nanoscale optomechanical approach coupling photonic and phononic degrees of freedom. All the free developed sensors will be assessed using metrological protocols and national primary standards in National metrological laboratories, to foster their feature exploitation in real application for end-users.