Sensors permeate our society, measurement underpins quantitative action and standardized accurate measurements are a foundation of all commerce. The ability to measure parameters and sense phenomena with increasing precision has always led to dramatic advances in science and in technology - for example X-ray imaging, magnetic resonance imaging (MRI), interferometry and the scanning-tunneling microscope. Our rapidly growing understanding of how to engineer and control quantum systems vastly expands the limits of measurement and of sensing, opening up opportunities in radically alternative methods to the current state of the art in sensing. Through the developments proposed in this Fellowship, I aim to deliver sensors enhanced by the harnessing of unique quantum mechanical phenomena and principles inspired by insights into quantum physics to develop a series of prototypes with end-users. I plan to provide alternative approaches to the state of the art, to potentially reduce overall cost and dramatically increase capability, to reach new limits of precision measurement and to develop this technology for commercialization. Light is an excellent probe for sensing and measurement. Unique wavelength dependent absorption, and reemission of photons by atoms enable the properties of matter to be measured and the identification of constituent components. Interferometers provide ultra-sensitive measurement of optical path length changes on the nanometer-scale, translating to physical changes in distance, material expansion or sample density for example. However, for any canonical optical sensor, quantum mechanics predicts a fundamental limit of how much noise in such experiment can be suppressed - this is the so-called shot noise and is routinely observed as a noise floor when using a laser, the canonical "clean" source of radiation. By harnessing the quantum properties of light, it is possible reach precision beyond shot noise, enabling a new paradigm of precision sensors to be realized. Such quantum-enhanced sensors can use less light in the optical probe to gain the same level of precision in a conventional optical sensor. This enables, for example: the reduction of detrimental absorption in biological samples that can alter sample properties or damage it; the resolution of weak signals in trace gas detection; reduction of photon pressure in interferometry that can alter the measurement outcome; increase in precision when a limit of optical laser input is reached. Quantum-enhanced techniques are being used by the Laser Interferometer Gravitational Wave Observatory (LIGO) scientific collaboration to reach sub-shot noise precision interferometry of gravitational wave detection in kilometer-scale Michelson interferometers (GEO600). However, there is otherwise a distinct lack of practical devices that prove the potential of quantum-enhanced sensing as a disruptive technology for healthcare, precision manufacture, national security and commerce. For quantum-enhanced sensors to become small-scale, portable and therefore practical for an increased range of applications outside of the specialized quantum optics laboratory, it is clear that there is an urgent need to engineer an integrated optics platform, tailored to the needs of quantum-enhanced sensing. Requirements include robustness, miniaturization inherent phase stability and greater efficiency. Lithographic fabrication of much of the platform offers repeatable and affordable manufacture. My Fellowship proposal aims to bring together revolutionary quantum-enhanced sensing capabilities and photonic chip scale architectures. This will enable capabilities beyond the limits of classical physics for: absorbance spectroscopy, lab-on-chip interferometry and process tomography (revealing an unknown quantum process with fewer measurements and fewer probe photons).

The interdisciplinary programme of research and software development I propose lies at the interface of physics, chemistry, and biology. Key target areas of this proposals, which my software will address, are coarse-grained modelling of DNA and RNA, the study of living systems and active matter far away from equilibrium, new soft energy and functional materials, enhanced encapsulation technologies and algorithms for new heterogeneous computing architectures. The proposed software development programme aligns with a number of key areas of research that have been identified as Physics Grand Challenges. One of them is the understanding the physics of life. This has the goal to develop an integrating understanding of life from single molecules to whole biological systems. DNA and RNA are the two biopolymers that are involved in various biological roles, most notably in the encoding of the genetic instructions needed in the development and functioning of living organisms and gene transcription. Coarse-grained models of DNA or RNA can provide significant computational and conceptual advantages over atomistic models, leading often to three or more orders of magnitude greater efficiency. But they are not only an efficient alternative to atomistic models of DNA as they are indispensable for the modelling of DNA on timescales in the millisecond range and beyond, or when long DNA strands of tens of thousands of base pairs or more have to be considered. This is for instance important to study the dynamics of DNA supercoiling, the local over- or under-twisting of the double helix, which is important for gene expression. Another Grand Challenge is the nanoscale design of functional material, which aims at engineering desired properties into the materials by using new principles rather than proceeding by trial and error. In the proposed programme I address different classes of functional and energy materials. One example are particle suspensions, which are fundamental in encapsulation technologies used in consumer products like foods, beverages, cleaning agents, personal care products, paints and inks or in the petrochemical industry or the micro-technological sector with lab-on-a-chip devices. Nanostructured charged soft materials are a new and highly promising avenue to more efficient, safer energy producing or storing devices and have great potential to fill technological gaps in the design of batteries and electrodes or the storage of renewable energy. A third Grand Challenge is the emergence and physics far from thermodynamic equilibrium. As life itself is a process far away from equilibrium, the context of this research is also closely related to aspects of living matter and often challenges the classical theories of statistical physics. The software that I will produce during this Fellowship will be open source and freely available for download from public repositories. Parts of it are likely to form later a key contribution to a highly optimised and standardised library of micro-, meso- and macroscale algorithms and a European infrastructure for the simulation of complex fluids. The software and research programme will be undertaken at the University of Edinburgh in collaboration with project partners at the University of Cambridge, the University of Oxford, University College London, the University of Barcelona, Spain and Sandia National Laboratories, USA.

The University of Edinburgh is purchasing a steady flow, high pressure (P < 120 bar) and temperature (T < 1000 K) optically accessible jet and spray research chamber. This chamber is unique within the UK. In addition, the university is also buying a single-cylinder optically accessible research engine. The chamber can be used to study sprays of all kinds; how they develop and react. The engine can be used to study transient fuel sprays as they interact with realistic in-cylinder flows. With this grant, the University of Edinburgh will acquire highly advanced laser diagnostics for multi-parameter measurements in the new chamber and engine, and in other related experimental devices, as a means to leverage the university's substantial equipment investment (£1.4 million) into a UK-wide Small Research Facility (SRF). The measurements to be acquired by this SRF include: a) A femtosecond laser system and ancillary devices (e.g. a second harmonic bandwidth compression system (SHBC), frequency resolved optical gating (FROG) to characterize the pulses etc.). The system will be used for hybrid picosecond/femtosecond rotational CARS (coherent anti-Stokes Raman spectroscopy), for line-image temperature and species (e.g. O2, N2, H2 etc.) in the jet/spray equipment, and ballistic imaging for investigation of primary breakup in highly atomizing sprays. b) High-speed (HS) 2-pulse, 532 nm wavelength laser and HS imaging systems for HS stereoscopic PIV, SLIPI imaging, and LII for particulate. A HS 1-pulse, 355/266 nm wavelength laser and HS intensifier system for HS PLIF, phosphors, and LITA. c) A phase Doppler instrument for droplet/particle size distribution and velocity in reactive jets and sprays The combined equipment and diagnostics will enable new studies on: a) Fuel sprays (including alternative fuels), and b) Supercritical materials synthesis (biofuels, pharmaceuticals, nano-catalysts, polymers etc.). Our research goals are multi-faceted. The research will enable more efficient combustion engines, reducing their impact on the climate. It will also make it possible to understand and then improve supercritical processing for materials synthesis, helping bring such products to market more effectively. In so doing we will address critical needs for both established industries and for key emerging industries across the UK.

We will establish a UK quantum device prototyping service, focusing on design, manufacture, test, packaging and rapid device prototyping of quantum photonic devices. QuPIC will provide academia and industry with an affordable route to quantum photonic device fabrication through commercial-grade fabrication foundries and access to supporting infrastructure. QuPIC will provide qualified design tools tailored to each foundry's fabrication processes, multiproject wafer access, test and measurement, and systems integration facilities, along with device prototyping capabilities. The aim is to enable greater capability amongst quantum technology orientated users by allowing adopters of quantum photonic technologies to realise advanced integrated quantum photonic devices, and to do so without requiring in-depth knowledge. We will bring together an experienced team of engineers and scientists to provide the required breadth of expertise to support and deliver this service. Four work packages deliver the QuPIC service. They are: WP1 - Design tools for photonic simulation and design software, thermal and mechanical design packages and modelling WP2 - Wafer fabrication - Establishing the qualified component library for the different fabrication processes and materials and offering users a multi-project wafer service WP3 - Integrated device test and measurement - Automated wafer scale electrical and optical characterisation, alignment systems, cryogenic systems to support single-photon detector integration) WP4 - Packaging and prototyping - Tools for subsystem integration into hybrid and functionalised quantum photonic systems and the rapid prototyping of novel, candidate component designs before wafer-scale manufacturing and testing The design tools (WP1) will provide all the core functionality and component libraries to allow users to design quantum circuits, for a range of applications. We will work closely with fabrication foundries (WP2) to qualify the design libraries and to provide affordable access to high-quality devices via a multi-project wafer approach, where many users share the fabrications costs. Specialist test and measurement facilities (WP3) will provide rapid device characterization (at the wafer level), whilst packaging and prototyping tools (WP4) will allow the assembly of subsystems into highly functionalised quantum photonic systems.

Cement manufacture accounts for about 5% of global carbon dioxide emissions, the single largest contribution of any man-made material. Despite this, research has shown that concrete is generally inefficiently used in the built environment. This fellowship will look to reduce the global environmental impact of concrete construction through a new method for the analysis of reinforced concrete structures that is well suited to producing the optimised designs that have the potential to significantly reduce material consumption. The new analysis method will be considered alongside practical construction processes, building on previous work by Dr Orr in this field, thus ensuring that the computationally optimised form can actually be built, and the research adopted, in industry. Most existing computational methods poorly predict the real behaviour of concrete structures, because their underlying mathematics assumes that the structure being analysed remains continuous as it deforms, yet a fundamental property of concrete is that it cracks (i.e. it does not remain continuous as it deforms). In contrast to finite element methods, this fellowship will develop a meshfree analysis process for concrete based on 'peridynamics'. The term 'peridynamic' (from 'near' and 'force') was coined by Dr Silling (see also statements of support) to describe meshfree analysis methods in solids. This new approach does not presume a continuous displacement field and instead models solid materials as a collection of particles held together by tiny forces, the value of which is a function of each particle's relative position. Displacement of a particle follows Newton's laws of motion, and is well suited to reinforced concrete since: 1) concrete really is a random arrangement of cement and aggregate particles; 2) failure is governed by tensile strain criteria, which is ideal as the only real way that concrete fails is in tension (all other failure modes in everyday design situations are a consequence of tensile failure) and the model can therefore accurately predict behaviour, and 3) since the elements fail progressively in tension, the peridynamic approach automatically models cracking behaviour, which is extremely difficult to model conventionally. A variety of force-displacement relationships can be defined to model the concrete, the reinforcement, and the reinforcement-concrete bond that together define the overall material response. The approach models the material as a massively redundant three-dimensional truss in which the randomly arranged particles are interconnected by elements of varying length. Although an optimal 'element density' has not yet been determined (see Section 2.4.1 in the case for support) proof of concept work has used tens of millions of particles and hundreds of millions of elements per cubic metre of concrete. From the simple rules and properties applied to these elements, all the complex behaviour of concrete can be predicted. Individual element definitions will be determined by laboratory tests and computational analysis, with both historic and new test data utilised. Crucially, the model has been shown in proof-of-concept work to be able to predict the cracking behaviour of concrete, overcoming a key computational challenge. Optimisation routines, in which material is placed only where it is needed, will then be integrated with the new analysis model to design low-carbon concrete structures. Consideration of the practical construction methods will also be given, building on previous work in this area by Dr Orr. The designs that result from such optimisation processes will have unconventional but completely buildable geometries (as evidenced in Dr Orr's previous work) - making them ideal for analysis using the proposed random elements approach.