The modern society's need for fast and reliable communications supports the operation of industries, the Internet of things, transportation systems, entertainment electronics and allows the exchange of information and knowledge. Most services rely on optical interconnects that provide low-cost, high-capacity, low-power consumption network connections, including data centers, satellites, supercomputers, and the Internet. According to the Cisco report, the network traffic, including the Internet, has increased to 40 Zettabytes of data in 2020. To put the numbers in perspective, the total data generated from the beginning of humanity until 2003 is 0.5% of a Zettabyte. Furthermore, the ever-increasing data traffic accounted for 12% of total global emissions in 2020. As a result, it is crucial to develop efficient networks with higher capacity and reduced power consumption. This project will contribute to more efficient modulators, which will impact communication systems used in ground and satellites to increase capacity, reduce pollution, and improve the environmental sustainability of optical interconnects in aerospace systems, data centers, high-performance computers, and networks. This research will exploit the properties of indium arsenide quantum dots, including 1. the radiation and temperature resilience to demonstrate a modulator for aerospace applications: indium arsenide quantum dot's radiation and temperature tolerance will outperform competing developments employing quantum wells, which 1. tolerates 10x and 5x orders of magnitude less radiation and temperature, 2. offers less bandwidth, and 3. high power consumption mainly when operating at high temperatures. This modulator will contribute to substitute current solutions, where heavy, power-hungry, and slow electrical interconnects by light, low-power consumption, and ultra-fast optical interconnects. The research will leverage 1. high-data rates satellite communications underpinning improved services, including fast Internet in remote and rural areas, and 2. the reduced size and weight will improve spacecraft fuel consumption and pollution towards net-zero emission. 2. the resilience to threading dislocation, and material stress of quantum dots, will be exploited to grow the modulator over silicon to bring more efficient modulators to the silicon photonic platform. Due to the weak modulating effects in silicon, it is not possible to produce efficient modulators. On the other hand, quantum dots exhibit stronger effects than silicon leveraging more efficient modulators and will outperform current quantum well monolithic integration approaches due to their resilience when grown over silicon. This development will impact the commercial optical interconnects using silicon-based photonic integrated circuits (PICs) and current networks relying on them. By integrating the quantum dot modulator into the existing commercial silicon-based PICs, the performance of ground optical interconnects will be improved, underpinning more efficient networks in data centers, high-performance computers, and the Internet. VTT, a silicon photonic foundry, will provide the silicon PICs. To ensure commercial relevance of the research, this project partners with key industrial players in the aerospace and data/telecom sectors and includes Airbus, ALTER Technology, Bay Photonics, STAR-Dundee and VTT. Additionally, the work will be carried out at the National Epitaxy Facility and the Institute for Compound Semiconductors. Hence, this project is well placed on training researchers in relevant industrial problems, evaluating the technology's commercial relevance, and guiding future developments.

The elementary unit of quantum information is the quantum bit or qubit. Like the classical bit, the qubit is a two-level system but with the intriguing ability to exist in a superposition of states. This means it can be in the on and off state at the same time which has profound implications if we consider quantum systems of more than one qubit. Instead of each qubit carrying any well-defined information of its own, the information is encoded in their joint properties. In quantum mechanics, the qubits are described as being entangled. The challenge is to find ways to harness quantum phenomena such as superposition and entanglement to construct a quantum computer that is able to perform computational tasks that are unattainable in a classical context. A very natural qubit is the electron spin. The energy difference between spin states of an electron can be precisely controlled by magnetic fields and, using the electron's charge, it is also possible to isolate and manipulate individual spins electrically. One route to achieve entanglement between spin qubits is to use the interaction of their electron wavefunction overlap by placing them in close proximity. While such an approach is feasible for a small number of qubits, a large-scale quantum processor which relies on direct nearest neighbour coupling becomes rapidly impractical. Here we therefore propose an alternative strategy which makes use of an intriguing quantum mechanical effect by which two spatially separated quantum bits become entangled if a measurement cannot tell them apart. As has been shown theoretically, measurement-based entanglement can be used to couple large numbers of physically separated qubits, building up so-called graph states. Computation is then achieved by a sequence of measurements on individual qubits that consumes the entanglement - known as one-way quantum computation - which is entirely different from the standard circuit-based approach. In practise this also requires the presence of a quantum memory where quantum information is stored to allow graph-state growth without the risk of losing existing entanglement. Here we propose to use a solid-state implementation which is ideally suited to this task: single As-dopants in isotopically pure Si-28. To fabricate the devices, we will use the most precise silicon dopant incorporation technique available: scanning tunnelling microscopy (STM) hydrogen resist lithography. The atomically precise incorporation of individual As-dopants is essential in satisfying a key requirement of the measurement-based entanglement protocol: qubit indistinguishability. Having fabricated the devices, we will be able to manipulate the electron spins of the As-dopants and create entanglement between remote qubits using projective measurements. For this we will be using radio-frequency reflectometry techniques which allows us to perform these tasks on a timescale significantly faster than electron spin lifetimes. Once entanglement generation has been achieved, hyperfine coupling will be used to transfer the quantum information from the electron to the As nuclear spin states. This approach takes advantage of record nuclear spin coherence, in the 10-100 second range, of dopants in Si and allows us to grow the entangled graph state. Moreover, since the As nucleus has a non-zero electric quadrupole moment and a four dimensional Hilbert space we will be able to control the nuclear spins electrically and store and control the equivalent of two qubits in each dopant. For a proof-of-principle demonstrator we will entangle four spatially separated devices, each consisting of two As-dopant atom qubits with all-to-all qubit connectivity, equivalent to a 16-qubit processor. The experimental efforts will be supported by theoretical studies to further develop the most efficient strategies for growing a resilient remote network taking into account realistic experimental parameters such as spin dephasing and signal loss.

The Innovative Manufacturing and Construction Research Centre (IMCRC) will undertake a wide variety of work in the Manufacturing, Construction and product design areas. The work will be contained within 5 programmes:1. Transforming Organisations / Providing individuals, organisations, sectors and regions with the dynamic and innovative capability to thrive in a complex and uncertain future2. High Value Assets / Delivering tools, techniques and designs to maximise the through-life value of high capital cost, long life physical assets3. Healthy & Secure Future / Meeting the growing need for products & environments that promote health, safety and security4. Next Generation Technologies / The future materials, processes, production and information systems to deliver products to the customer5. Customised Products / The design and optimisation techniques to deliver customer specific products.Academics within the Loughborough IMCRC have an internationally leading track record in these areas and a history of strong collaborations to gear IMCRC capabilities with the complementary strengths of external groups.Innovative activities are increasingly distributed across the value chain. The impressive scope of the IMCRC helps us mirror this industrial reality, and enhances knowledge transfer. This advantage of the size and diversity of activities within the IMCRC compared with other smaller UK centres gives the Loughborough IMCRC a leading role in this technology and value chain integration area. Loughborough IMCRC as by far the biggest IMRC (in terms of number of academics, researchers and in funding) can take a more holistic approach and has the skills to generate, identify and integrate expertise from elsewhere as required. Therefore, a large proportion of the Centre funding (approximately 50%) will be allocated to Integration projects or Grand Challenges that cover a spectrum of expertise.The Centre covers a wide range of activities from Concept to Creation.The activities of the Centre will take place in collaboration with the world's best researchers in the UK and abroad. The academics within the Centre will be organised into 3 Research Units so that they can be co-ordinated effectively and can cooperate on Programmes.

We intend to develop a new user-friendly technology that would enable small devices to be cooled to exceedingly low temperatures (<100mk). Such a capability will allow diverse and futuristic applications to flourish. These include the detection of black holes, cancer detection and quantum computing. We propose to do this by using an electronic cooling process where relatively energetic (hot) carriers (electrons or holes) quantum mechanically tunnel out of a medium, thereby causing the average electronic temperature in the medium to decrease. The application of this process to realise extremely low temperatures is very new, and we want to greatly improve its efficiency by introducing a new generation semiconductor SiGe into the design of the electronic cooler and, along with it, the well developed silicon processing techniques - so that, ultimately, such coolers can be produced economically and to industrial standards. Coolers will be fabricated around the periphery of a small silicon chip with thermal links to the active device ( payload ) mounted in the centre of the chip. This requires very good thermal design such that the electronic cooler efficiently cools the payload. However, in some cases, it is only necessary to cool the electrons / not the lattice atoms; here SiGe gives a lot of flexibility in controlling the thermal coupling between the electrons and the lattice. Such electronic coolers can operate from a starting temperature of 0.3K, which can be produced by a cryogenic fluid-free closed-cycle helium cryostat, so that a turn-switch technology can be envisaged enabling access to ~10mK working environments. This will be a huge technology step forward, as existing techniques require massive and complex cryogenic fluid-based equipment.During the first phase of the project we will examine several approaches to the realisation of effective electronic cooling, exploiting the wide range of fundamental electronic conditions that can be obtained at very low temperatures in SiGe with its associated metal silicides / thereby enhancing carrier transport and thermoelectric effects. The new coolers will then be tested in two areas of great topical interest, namely radiation detectors and quantum information devices. They could dramatically enhance our ability to detect, for example, the photons that emanate from the earliest black holes, with satellite-based detectors operating at <100mK. And, very significantly, such detectors could revolutionize the fluorescence light detection that is used extensively in biomedical research, enabling advances in our understanding of genetically-based diseases (e.g. cancer) and the workings of a single cell. Furthermore, the computational vista that is opened-up by the quantum computing era requiring qubit devices operating at 10-20mK, is truly awe inspiring. Warwick is co-ordinating the project and has assembled a tightly knit consortium of scientists and engineers with appropriate expertise from four UK universities -Warwick, Cardiff, Leicester and London(Royal Holloway) - and four leading-edge companies, concerned with the development of this technology and the demonstration of its applicability and advantages in two key areas. We are also working closely with Europe's leading centre on mK coolers (Helsinki University of Technology). The UK is exceedingly well positioned to derive benefit from this genuinely new and exciting technology, and this project will sow the seeds for its realisation.

There is currently a timely need to design and manufacture renewable materials for high volume structural applications and decouple our economy from fossil-derived non-renewable resources. Cellulose-based natural fibres are the prime candidate for the production of low-cost high-performance renewable composites. However, there is still a property-performance gap between natural fibre-reinforced polymers and traditional fossil-derived engineering materials (see Fig. 1), as the high tensile stiffness (up to 165 GPa) and strength (at least 1 GPa) of cellulose microfibrils have yet to be fully exploited in a composite setting. Nature has been very efficient at manipulating and exploiting cellulose microfibrils in wood (a natural composite) to produce high performance materials. This project will take inspiration from wood and manufacture the world's first "artificial wood", i.e. cellulose microfibril-reinforced lignin composites with the native cellulose-I structure preserved (mimicking wood cell wall), using simple and intrinsically scalable manufacturing concepts. The proposed research activities are structured around (i) manufacturing "artificial wood" from (low cost) ionic liquid, (ii) design and manufacture of unidirectional and continuous "artificial wood" fibre-reinforced renewable composites and (iii) optimising the techno-economics and lifecycle of "artificial wood" manufacturing. It is envisaged that the resulting "artificial wood" will target engineering applications that cannot be achieved by conventional bio-based polymers or renewable natural fibre-reinforced polymers alone and could serve as alternative to traditional glass fibre-reinforced polymers.