To address really valuable problems, Quantum Computing machines must scale to 100k to millions of physical qubits. Machines of this size cannot be constructed monolithically - the roadmap to utility inevitably mandates a modular and networked architecture of processors that are woven together to form a larger, more powerful machine. This project directly tackles one of the most critical components of such a distributed quantum computer: the need for a highly efficient interface between qubits inside computing cores and the wider light-based quantum networking infrastructure. HyperIon will prove the significant aspects of a first-of-its-kind Qubit-Photon Interface (QPI) prototype, with a clear path towards a full system-level demonstrator and a clear path towards integration with commercial Quantum Processing Units (QPUs) and robust mass production. Led by Nu Quantum (NuQ), the project partners are the University of Sussex (UoS) Ion Trap research group, and Cisco providing independent end-user input and commercial exploitation support.A foundry subcontractor is assigned, bringing in specialist fabrication techniques suitable for mass-production. Project will demonstrate and deliver improvements over the current state-of-the-art in the domains of: **Performance (NuQ)**: single-ion QPI system capable of a 50x increase in entanglement rate together with state of art remote fidelity. **Path to QPI-QPU integration (UoS)**: innovative wafer-based trap for shuttling a qubit to a cavity-ion interaction zone, compatible with different vendors' subsystems. **Path to Manufacturability (NuQ-Subcontractor)**: foundry-compliant designs to allow large-scale manufacturing of ion-traps with integrated cavities The project directly supports the UK's leadership in this critical and emerging market of Quantum Networking to scale Quantum Computing by accelerating the progress of QPI development between Lead Nu Quantum and academic partner University of Sussex.

Credible sources estimate the Quantum Computing (QC) market will have a market value of $90-$170B annually in a Fault Tolerant era. It is increasingly accepted that to reach commercial viability, Quantum Networks (QNs), will be needed to scale QC - increasing the number and quality of qubits. The timely development of QNs will thus gate the widespread adoption of QC and the transformative benefits it can bring. Ultimately QNs will be as essential to QC as classical networking is to High Performance and Cloud computing. Currently, advancements in Quantum Networking are academically driven experiments in highly controlled laboratory environments. While essential to improving state-of-the-art performance metrics, they neglect crucial factors that will allow for real-world deployment in more industrial and IT-like environments, where they will ultimately need to operate _resiliently_ and at _large scale_. Project LYRA accelerates and de-risks the path to _deployable_ and _scalable_ quantum-networking specifically for the use-case of interconnecting Quantum Computing nodes in data-centres. The project concentrates on _pragmatic_ and _demonstrable_ improvements in the _packaging_ and _usability_ of quantum networking technologies, while still maintaining appropriately high levels of performance. We will deliver a world-first deployable Quantum Networking Unit prototype, the networking heart of a Quantum Computer Cluster. Cisco will be the End User for this project. As the world's leading supplier of classical networking, Cisco has unparalleled experience in delivering scalable, resilient and performant data-centre services. Cisco have committed to contribute to, and **underwrite, key system requirements** and **evaluate final deliverables**, potentially at a UK facility. Additionally, to demonstrate product-market fit and to ensure the construction of an extensible & relevant roadmap, Nu Quantum have assembled a Customer Requirements Council (CRC). The 5-party CRC represents leading QC vendors and global data-centre technology providers.

Quantum Computing (QC) will offer societal benefits through solving intractable problems across multiple scientific domains. The motivation for this project is to tackle the industry's biggest challenge: scaling. It is increasingly recognised that _useful_ QC can only be delivered by networking together multiple QC nodes into a larger (data-centre-scale), more performant and better Error-Corrected computing service. There is an urgent business need to architect and deliver a solution for effective networking of QCs - photonic networking being the most promising route, relevant to all qubit types. In this project, we will respond to the challenge of charting a path towards Distributed QC (DistQC) by modelling the performance of a Distributed QC, developing benchmarking protocols, and reviewing and refining the logical process that affect performance.

Project CALYX : Cold-Atom Light via efficient Cavity Extraction This project addresses a fundamental, rate-limiting, aspect of matter-to-light conversion; proving a principle of cavity-coupling that can unlock greater performance from quantum computing, sensing and networking systems. This project takes Nu Quantum's existing microcavity know-how into ColdQuanta's proven cold-atom system-platform; maintaining a large separation between the atoms and the cavity surfaces, whilst providing strong atom-cavity coupling to enable efficient photon extraction. The project approach is to demonstrate - in a realistic environment - techniques that can _offer significant competitive advantage_ to high-value quantum systems offering compute, security and sensing functionality; allowing customers and partners a highly differentiated offering.

Nu Quantum, University of Cambridge, University of Oxford, and Cisco Systems come together to develop and commercialise integrated quantum photonic technology aimed at enabling entanglement-based networking of multi-core quantum computing clusters. Project Medusa employs Integrated Photonic technology to develop a Quantum Networking solution aimed at interconnecting small clusters of Trapped Ion Quantum Computers (TIQC). The motivation for this project is the scaling of TIQCs. TIQCs are the best-performing qubit technology today, however it is widely accepted that it will be extremely difficult to create TIQC cores of over 50-100 qubits. Interconnecting small, efficient clusters using photonic networking is the most promising solution to achieve large, powerful computers. The technological challenge is that there currently exist no commercially-available quantum networking photonic products - integrated switches, entanglement optics, and single-photon detectors - which meet the requirements of speed and efficiency, at the required wavelengths. The main output of this project is a world-first prototype of an integrated 4-node switched entangler which targets the necessary requirements of rate, loss, and wavelength to enable multi-core TIQC.

Quantum computation is heralded as a paradigm shifting technology, to revolutionise drug discovery, chemistry, communications, and even our understanding of the natural world. However, the vast promises of any scientific discovery must be measured against the engineering challenges which hold back its delivery. In this project, partners from industry, academia, and the public sector will produce a core component that is critical to the realisation of scalable quantum computing. This will help enable the efficient interfacing of light and matter at the single quantum level, which will allow quantum processing nodes to combine resources and operate in synchronicity over vast distances. The construction of networked processors from large numbers of smaller modules will lift one of the principal technical restrictions on the route to full-scale quantum computation. At its heart, our challenge is to create a device enabling the transfer of quantum information between trapped atomic ions and single optical photons. However, while atoms may be readily trapped with electric and magnetic fields, 'trapping' light remains a considerable endeavour. The natural solution is to confine the light between two micro-mirrors in the form of a resonant optical cavity, engineering a strong interaction between the atom and optical field via their mutual overlap. However, the realisation of optical cavities as a quantum interface has been historically limited to an academic environment, relying upon fabrication methods that are unsuited to the construction of the quantum computers of the future. To fulfil the objectives of this project, we will harness and develop innovative technologies in the creation of a robust, turn-key cavity interface suitable for scalable integration in ion and atom-based quantum networks.

Data is one of the world's most valuable commodities -- affecting every person, every company, every government, everywhere. Most of the world's cybersecurity infrastructure is based on the exchange and use of digital cryptographic keys. Random number generators (RNGs) are essential components of this existing infrastructure, and newer technologies such as quantum key distribution. Quantum random number generators (QRNGs) are devices that utilise the inherent randomness in natural physical processes to create random numbers, assured unique to each device if the process is truly quantum, and are one of the first practical implementations of quantum technologies. A key differentiator of quantum RNGs over other conventional pseudo RNGs, crucial for all security applications, is that identically manufactured and prepared pseudo RNGs are certain to produce the same random sequences, while QRNGs are not. A method for providing authoritative assessment of the unique randomness produced by QRNGs does not currently exist. This project will address that need, thereby overcoming this important technological barrier to their commercial and industrial exploitation, and maximising UK return from quantum technology research in this field. Current tests for random number generators (RNGs), based on numerical analysis of their outputs, give information about the statistical properties of the output randomness but cannot assure that the output is unknown to others. Stronger assessment is possible for QRNGs, since in addition to numerical analysis to assure randomness, the physical process used to create the output can be modelled and physically tested. Assessing the "quantumness" of the process also assesses the privacy of the output. This project will take QRNGs that are either already on the market or near-market prototypes and implement this assessment approach. It will thereby provide the expertise and capability for creating a UK assessment process for QRNGs.

Major organisations rely on strong encryption, including the process of encryption key agreement. Future quantum computers have the potential to compromise key agreement schemes based on asymmetric encryption and widely deployed Public Key Infrastructure. Over long distances and without quantum repeaters, Business Continuity (BC) can be maintained if commercially and technically viable Satellite Quantum Key Distribution (SatQKD) becomes available in time. Current free space optical approaches are not considered commercially viable because they can only operate at night time and in clear sky conditions; and by waiting for overhead satellites in Low Earth Orbit. The future BC market, anticipated to be worth billions of pounds, will be addressed by this project through accelerated commercialisation of the SatQKD technologies necessary for operation during daylight hours, cloudy skies and other weather conditions. The project will combine and align technical developments from UK SME's within a system context from Airbus: a major provider of UK-developed secure satellite communication systems. The objective of this project is to prepare new modular flexible system architectures, technology landscape surveys and technology development roadmaps for lower cost, longer range, free space optical quantum communications directed towards institutional and commercial customers. The primary focus of Innovation in this project is to extend the envelope of Satellite-to-Ground QKD operations beyond the current state of the art: to enable daytime operation, cloud tolerance and reach key distribution rates several orders of magnitude faster than existing demonstrators. The project will influence and enhance the coherence of academic research, SME developments, and prime system integration readiness for operational quantum secured communications.

AirQKD establishes a UK ecosystem, from single-photon components to networked quantum systems, to protect short to mid-range communication in free space. In particular we carry out pilot demonstrations of the enabling infrastructure for quantum-secure 5G and autonomous and connected vehicles.

Quantum Key Distribution (QKD) facilitates the secure sharing of encryption keys using quantum technology. These keys can encrypt data for transmission over conventional fibre links across any distance, but QKD itself is limited over fibre to around 150km. Beyond this, 'trusted nodes' are required, but at major risk of creating security vulnerabilities. A number of fibre QKD networks are being built, including in the UK, but all are subject to this constraint. QKD through free space is less sensitive to distance. Thus, satellites provide the means for distributing keys across very large distances between end users spread across countries or continents - they are a facilitator of global QKD networks. Satellite components in QKD networks are being planned or researched in a number of countries. A consortium led by Arqit aims to establish the world's first commercial QKD satellite constellation. The first satellite is being build under contract with the European Space Agency, with a quantum payload being manufactured by European partners. There is an opportunity for the UK quantum technology industry to leapfrog other countries by creating a capability to manufacture the next generation of space QKD payloads here in the UK. The "Quantum Payload Factory" project will work with organisations across the UK to progress the state of the art of promising quantum communications technologies, understand their potential to enhance the performance of Arqit's global QKD system, validate their capabilities and technology readiness, engineer them to become "space ready" and develop an enhanced performance payload design that brings these new UK technologies into the second generation of Arqit satellites.

Nu Quantum partners with the National Physical Laboratory to develop cutting-edge single photon sources and detectors to enable a step-change in performance of free-space quantum key distribution. NPL will use Nu Quantum's arrays of room temperature devices to optimise an automated quantum optical measurement suite: a step towards national standardisation of quantum devices through large-scale measurement.

"Quantum computers will soon be powerful enough to crack current encryption protocols in seconds - a global threat to all industries, governments and individuals. Quantum cryptography provides a robust solution. Governments are acting now - only within Autumn 2018, over £2 bn public investments in Quantum Technologies have been announced across Europe. One of the already-marketed quantum cryptography solutions is Quantum Key Distribution (QKD). Here, secret keys used to encrypt messages, are sent from A to B encoded in quantum objects: in single-photons. The most efficient way of achieving long-distance QKD is via Satellite. Ground-based optic fibre will most-likely enable short distances. Efforts towards the implementation of Satellite QKD (SatQKD) have started, with over 21 missions across the world encompassing governments, space agencies, start-ups and established industrial players. The main problem faced by SatQKD is the low rates of communication. All current SatQKD missions use lasers as photon sources. Lasers are ill-equipped to deliver single-photons (instead were designed to deliver trillions of them), yielding low rates that will result in an early data transfer bottleneck. In addition, they are usually large and power-hungry objects. Nu Quantum, recent spin-out from the University of Cambridge, has developed and patented a method to fabricate true single-photon sources. Each source is predicted to deliver over 10x higher rates than a laser. Further, our technology allows to fit hundreds of sources per square centimetre, it is on-a-chip and has low power requirements. This technology will be the key enabler of high-throughput, next-generation Satellite QKD. This project will allow Nu Quantum, with the University of Cambridge as academic partner (Physics and Materials Science Departments), to run a key feasibility study on the performance of these sources for SatQKD. This is the world's first attempt to use true quantum light sources for SatQKD. Commercial partner Dot Quantum, QKD expert and quantum cryptography consultant, will model the sources to benchmark against existing solutions. The project also includes a market strategy report focused on user needs, which will inform Nu Quantum's exploitation plan towards raising private investment. A commercial opportunity at the interesting intersection between Space Tech, Cybersecurity and Quantum."