o achieve this vision, we will address major global research challenges towards the establishment of the "quantum internet" —?globally interlinked quantum networks which connect quantum nodes via quantum channels co-existing with classical telecom networks. These research challenges include: low-noise quantum memories with long storage time; connecting quantum processors at all distance scales; long-haul and high-rate quantum communication links; large-scale entanglement networks with agile routing capabilities compatible with - and embedded in - classical telecommunicatons networks; cost-effective scalability, standardisation, verification and certification. By delivering technologies and techniques to our industrial innovation partners, the IQN Hub will enable UK academia, national laboratories, industry, and end-users to be at the forefront of the quantum networking revolution. The Hub will utilise experience in the use of photonic entanglement for quantum key distribution (QKD) alongside state-of-the art quantum memory research from existing EPSRC Quantum Technology Hubs and other projects to form a formidable consortium tackling the identified challenges. We will research critical component technology, which will underpin the future national supply chain, and we will make steps towards global QKD and the intercontinental distribution of entanglement via satellites. This will utilise the Hub Network's in-orbit demonstrator due to be launched in late 2024, as well as collaboration with upcoming international missions. With the National Quantum Computing Centre (NQCC), we will explore applications towards quantum advantage demonstrations such as secure access to the quantum cloud, achievable only through entanglement networks. Hub partner National Physical Laboratory (NPL) working with our academic partners and the National Cyber Security Centre (NCSC) will ensure that our efforts are compatible with emerging quantum regulatory standards and post-quantum cybersecurity to bolster national security. We will foster synergies with competing international efforts through healthy exchange with our global partners. The Hub's strong industrial partner base will facilitate knowledge exchange and new venture creation. Achieving the IQN Hub's vision will provide a secure distributed and entanglement-enabled quantum communication infrastructure for UK end-users. Industry, government stakeholders and the public will be able to secure data in transit, in storage and in computation, exploiting unique quantum resources and functionalities. We will use a hybrid approach with existing classical cyber-security standards, including novel emerging post-quantum algorithms as well as hardware security modules. We will showcase our ambition with target use-cases that have emerged as barriers for industry, after years of investigation within the current EPSRC QT Hubs as well as other international efforts. These barriers include security and integrity of: (1) device authentication, identification, attestation, verification; (2) distributed and cloud computing; (3) detection, measurement, sensing, synchronisation. We will demonstrate novel applications as well as identify novel figures of merit (such as resilience, accuracy, sustainability, communication complexity, cost, integrity, etc.) beyond security enhancement alone to ensure the national quantum entanglement network can be fully exploited by our stakeholders and our technology can be rapidly translated into a commercial setting.

Quantum technology will revolutionise many aspects of life and bring enormous benefits to the economy and society. The Centre for Doctoral Training in Quantum Informatics (QI CDT) will provide advanced training in the structure, behaviour, and interaction of quantum hardware, software, and applications. The training programme spans computer sciences, mathematics, physics, and engineering, and will enable the use of quantum technology in a way that is integrable, interoperable, and impactful, rather than developing the hardware itself. The training programme targets three research challenges with a strong focus on end user impact: (i) quantum service architecture concerns how to design quantum networks and devices most usefully; (ii) scalable quantum software is about feasible application at scale of quantum technology and its integration with other software; and (iii) quantum application analysis investigates how quantum technology can be used most advantageously to solve end user problems. The QI CDT will offer 75+ PhD students an intensive 4-year training and research programme that equips them with the skills needed to tackle the research challenges of quantum informatics. This new generation will be able to integrate quantum hardware with high-performance computing, design effective quantum software, and apply this in a societally meaningful way. The QI CDT brings together a coalition with national reach including over 65 academic experts in quantum informatics from five universities - the University of Edinburgh, the University of Oxford, University College London, Heriot-Watt University, and the University of Strathclyde - and three public sector partners - the National Quantum Computing Centre, the National Physical Laboratory, and the Hartree Centre. A network of over 30 industry partners, diverse in size and domain expertise, and 9 leading international universities, give students the best basis for meaningful and collaborative research. A strong focus on cohort-based training will make QI CDT students into a diverse network of future leaders in Quantum Informatics in the UK.

Over the next few decades, quantum computing (QC) will transform the way we design new materials, plan complex logistics and solve a wide range of problems that conventional computers cannot address. The Hub for Quantum Computing via Integrated and Interconnected Implementations (QCI3) brings together >50 investigators across 20 universities to address key challenges, and deliver applications across diverse areas of engineering and science. We will work with 27 industrial partners, the National Quantum Computing Centre, the National Physical Laboratory, academia, regulators, Government and the wider community to achieve our goals. The Hub will focus on where collaborative academic research can make transformative progress across three interconnected themes: (T1) developing integrated quantum computers, (T2) connecting quantum computers, and (T3) developing applications for them. Objectives for each are outlined below. (T1) Developing integrated quantum computing systems, with a goal of creating quantum processors that will show real utility for specific problem examples. Objectives: OB1.1: Demonstrate quantum advantage in analogue platforms with neutral atoms and photons OB1.2: Make neutral atom quantum simulation platforms available in the cloud OB1.3: Develop new applications for these and other near-term systems (T2) A key challenge of building the million qubit machines of the future is that of 'wiring' together the quantum processors that will create such a machine. The Hub will develop technologies that help achieve this and develop models to understand how such machines will scale. Objectives : OB2.1: Develop interconnect technologies for quantum processors OB2.2: Demonstrate blind computing and multi-component networks with trapped ion quantum computers OB2.3: Demonstrate transduction and networking of superconducting processors (T3) Developing applications in science and engineering, including materials design, chemistry and fluid dynamics. Objectives: OB3.1: Develop new methods for materials and chemical system modelling and design, fluid dynamics, and quantum machine learning OB3.2: Identify the nearest routes to quantum advantage for these application areas OB3.3: Develop implementations of these algorithms on T1 and T2 Hardware These will be supported by work in overarching tools (T4) that can be used across the themes of the Hub, including error correction, digital twins, verification and software stack optimisation. Skills and training Hub partners will work with end-users, our students and researchers, and partners across the UK National Quantum Technologies Programme (UKNQTP) to ensure members of the Hub have the skills they need. Specific objectives include: Provide training in innovation, commercialisation and IP, Equality, Diversity and Inclusion and Responsible Research and Innovation (RRI) to Hub partners Provide reports and training to end-users, working in partnership with the NQCC and others Continue to provide advocacy and advice to policy makers, through work in such areas as RRI Exploitation and Engagement: The Hub will build on the strong engagement activities of the UK programme, further developing the technology pipeline. We will play a key role in strengthening and expanding the UK ecosystem through events, networking and education. Specific goals are to: Broaden the partnership of the Hub, bringing new academic, government and industrial partners into the Hub network Contribute to regulation and governance through programmes of work in standards and RRI, and close collaboration with UKNQTP partners Support the generation and protection of intellectual property within the Hub, and its exploitation Develop Hub and cross-Hub outreach initiatives, working with the RRI team, to help ensure the potential of quantum computing for societal benefit can be realised

Research Context: The internet has become an indispensable tool in today's society. However, data transfer over this network is fundamentally insecure. Security of data and protection against identity theft and cyber-attacks is of crucial importance for our current and future society. These security concerns are addressed with the invention of a quantum internet - a network based on encoding and transmitting information as quantum bits - as the principles of quantum physics ensure total and fundamental secure communication. Quantum networks are the missing key technology, however, a major roadblock remains to be overcome: scalability. Building quantum networks relies on generating large numbers of individual quantum objects (in this case photons - single quanta of light) and performing controlled interactions between them. However, the fragile nature of quantum objects means that successfully preparing even one happens by chance - like a coin toss. Adding more quantum objects to a network is like adding more coins to toss - the overall chance of getting all heads reduces greatly, and so a large-scale quantum network has never been achieved. I will address this crucial issue with a quantum optical memory - a device that can store and recall photons on demand enabling one to synchronise the successful "coin tosses" across the network. The overall aim is to build and exploit a high-performance light-matter quantum network. Aims/Objectives: To achieve this aim, I will utilise my expertise in quantum light-matter interactions to build an ultrafast, high-efficiency, low-noise quantum memory at wavelengths already used in the telecoms industry. I will utilise two complementary platforms with miniaturisation capability important for scale - warm alkali vapours and cryogenically cooled rare-earth ions in solids - together with quantum memory protocols that I have pioneered, to deliver a quantum memory performance at an unprecedented level. With this device, I will demonstrate a hybridised quantum light-matter interface with the storage and on-demand recall of photons ensuring that the quantum properties of the light are preserved. This demonstration forms the key technology for the basis of the network, where I will now use two quantum memories to efficiently interface and store photons from disparate quantum sources at remote locations - a two-node network. I will then scale this light-matter network to allow for the control of multiple memories and photons to enact quantum communication tasks for the first-time. Potential Applications: In the same way the invention of the transistor led to rapid advances in computation and communications, revolutionising the 20th century, quantum networks are the underpinning technology that have the potential to bring significant change and long-term social-economic impact in the 21st century. A high-performance light-matter quantum network will bring inherently secure communication, more accurate global clock synchronization for enhanced GPS accuracy, and could even allow extending the baselines of telescopes for improved observations. Networks of quantum objects can form quantum computers that are powerful enough to solve problems that current computers cannot, with the potential to impact methods of research in the healthcare, pharmaceutical and green energy sectors. Efficient simulation and optimised computation using quantum networks could provide benefits in epidemiology and genetic research, cut costs in medication design to treat new diseases, and help improve artificial light-harvesting devices for alternative energy sources, with many more useful applications likely to be discovered in the coming decades. In the shorter term, my project will aid in training the next generation of quantum scientists and generate valuable IP to be exploited by spinout companies, further forwarding the emergent quantum technologies industry in the UK.

Quantum mechanics has been known for weird nature it predicts: It allows several distinct states to exist simultaneously (quantum superposition) and super-strong correlations (quantum entanglement) between particles. Quantum computing (QC) makes use of this weird nature for faster and more accurate data processing and secure data protection than any conventional computers can offer. Five use cases for QC identified by the UK National Quantum Computing Centre are optimisation, quantum chemistry, fluid dynamics, machine learning and small molecule simulation. The UK government has long recognised the future potential of QC, having established in 2014 a national network of Quantum Technology Hubs. Now, QC appears as one of three "foundational technologies" for the digital sector in the UK National Plan for Growth. International development in quantum technology is proceeding rapidly, with a recent, early academic demonstration of digital quantum advantage by the US technology monolith Google. Besides established companies, QC development has spawned many start-up companies worldwide with UK representations including Cambridge Quantum Computing, ORCA Quantum Computing, Oxford Ionics, Oxford Quantum Computing, Phasecraft, Quantum Motion, Rahko and Riverlane. The increasing scale of QC raises several key technological challenges: (1) Isolated control and inter-system crosstalk, (2) Efficient classical monitoring and feedback, and (3) Efficient quantum access to large amounts of relevant problem data. Indeed, facing similar problems in conventional computing, researchers in information and communication technology (ICT) have been working on 'distributed computing', including cloud computing and optimal processing of distributed data. With ICT and QC researchers working together, this multi-disciplinary team will tackle the timely challenge of the design and efficient use of networked clusters of quantum devices for distributed quantum information processing (DQIP). While complementing the on-going efforts on scalable quantum computing, this project aims to develop a clear and feasible roadmap to practical DQIP and to introduce lynchpin design principles to enable cohesive efforts across each of the complex and strongly inter-related aspects of DQIP development. This project will therefore also contribute to showing significant quantum advantages as quantum systems grow toward the industrial scale, increasing certainty in the timeline and practical industrial evaluation of QC, laying a foundation for increased investment and growth in this area for the UK economy moving forward. Specifically, this project will explore four key aspects of the design problem: (1) At the application layer, we set concrete structures and requirements for the algorithm and architecture; (2) At the algorithm layer, we define communication requirements in a hybrid environment of quantum and conventional processing nodes; (3) At the network layer, the required quantum processes will be optimised for the maximum connectivity; and (4) At the optical interconnect layer, the encoding and efficient transmission of quantum information in photonic systems will be studied. Our goal is to bridge the gap between QC and the established tools and methods in ICT, and to focus in on the strong network of inter-related constraints between these different aspects of the design problem to enable the development of practical DQIP. To achieve this goal, the project brings together an investigative team with strong track records for prior research in diverse and complementary fields, including computational finance and fluid dynamics, optimised networked systems and distributed computing, and quantum information and optics.