I propose investigating the use of ionic liquids for materials treatment, specifically in nanotechnology. Nanotechnology is the manipulation of matter at molecular scales close to one billionth of a meter. Progress in manufacturing at this scale has enabled the fabrication of modern electronic and biomedical technologies. However, more advanced processes are required to manufacture even faster computers, better drug delivery systems, and many other future technologies. In this project, ionic liquids will be used to access new options for these manufacturing processes. These exciting new liquids have been developed over the last two decades for a range of chemistry and energy storage applications. Ionic liquids consist entirely of charged complex molecules (ions) at room temperature, which allows for a new approach to nanotechnology manufacturing with a device known as an Ionic Liquid Ion Source (ILIS). In an ILIS, the ionic liquid covers a sharp needle. By applying a high voltage to this needle, it is possible to produce a beam of ions from the liquid. This spray can be directed towards a material for treatment. Different ion combinations would be available for various materials processing applications, as ionic liquids have been extensively studied, and hundreds of stable compositions have been discovered. For example, the beam can contain reactive ions, and can be used to remove material from silicon, a common material used in microprocessors. Varying the beam conditions and composition can allow for both the erosion of material (subtractive method) and the deposition of a thin film on the surface or to create a structure (additive method). I will explore the interactions of the ILIS beam with different materials, study the use of ILIS for material removal and deposition, and investigate the possibility of focusing the beam of ILIS for careful processing of materials at the nanoscale. In the first stage of this fellowship (2020-2024) a vacuum chamber was constructed; this chamber is being used for detailed characterization of emission from different ionic liquids. ILIS beams are comprised of several different ion types, and so a filter is being used to separate these components. The separate ion types are being fired towards a variety of materials to understand how specific ions react with different targets. These fundamental studies are being complemented by experiments that use an ILIS to remove material and create a nanoscale pattern. Additional experiments can be performed with an array of ILIS devices, in order to achieve higher throughput. The possibility of depositing thin films of ionic liquids from an ILIS beam is also under study. The fellowship is developing a focused ion beam (FIB) from an ILIS; FIB machines take the beam of particles from an ion source and focus the particles onto a nanometre sized-spot on a target, thus allowing localized modifications to a sample. Computer simulations are being used to design a bespoke focusing setup in which the ILIS is being installed. In the renewal stage of the fellowship (2024-2027), experiments will be undertaken to quantify how well the ILIS-FIB beam is focused, using different ionic liquids and different operating conditions in the focusing setup. The ILIS-FIB platform will be used in several applications, for instance microscopy or precise milling at the nanoscale. Another avenue of research will be to study the possibility of creating three-dimensional nanostructures by depositing material with the focused ion beam of ionic liquid particles.

Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is a powerful and widely used method for surface chemical analysis. The technique involves bombarding a sample with a high energy primary ion beam and detecting the chemistry of the molecular secondary ions that are ejected. The research group at the University of Manchester has over 30 years acquired an internationally-leading reputation for the development and analytical application of the ToF-SIMS technique. In recent years the development of novel primary ion beams such as C60 and massive gas clusters (e.g. Ar2000) has extended the range of chemistry that can be detected and allowed in-depth and 3D molecular analysis beyond the surface region. This has greatly accelerated the uptake of the technique in academic and industrial labs, to measure complex molecular systems such as biological cells and advanced materials and devices, and to make advances in healthcare diagnostics and manufacturing. Conventionally, ToF-SIMS measurements rely on signal averaging (SA) over multiple experimental cycles to maximise the signal-to-noise ratio and resulting sensitivity. Each cycle consists of a short (nanosecond) primary ion pulse, followed by the measurement of the flight time (up to 0.2 milliseconds) of secondary ions, ejected from the sample, to a detector to determine their mass-to-charge (m/z) ratio. The m/z ratio in turn provides information about the chemistry of the detected ions and therefore of the sample. In this configuration the system waits for all secondary ions in each cycle to reach the detector before beginning the next cycle - the data is inherently sparse. The resulting poor duty cycle limited by the flight time of the largest m/z ion leads to inefficient (<0.1%) primary ion usage and long experimental measurements. In producing a pixel-by-pixel chemical image of the sample surface very many (~1 million) experimental cycles are used to gain the required sensitivity, often taking several hours of experiment time. Extending the analysis to the sub-surface region (depth-profiling or 3D imaging) requires many times longer or involves a different methodology whereby only a small fraction of the sample is analysed and potentially important information is lost. Here we present a multiplexing methodology in which multiple secondary ion packets are measured simultaneously. This allows much more efficient (up to 50%) usage of the primary beam for signal generation and ensures that the summed mass spectra more rapidly converge to a sensitive and accurate measurement. This represents a completely new paradigm for ToF-SIMS. The development of the necessary hardware (ion optics and electronics), computer control and data processing software is an adventurous task for which we have put together a multidisciplinary academic and industrial team, uniquely positioned to meet this challenge. The result will be greatly improved signal-to-noise and therefore greater sensitivity in shorter experiments. This will increase the throughput and analytical power of the ToF-SIMS technique and extend the range of complex samples that can be analysed. Benefits of improved analytical power will impact on many sectors using this technology including advanced manufacturing and healthcare.

A programme of a research is proposed to advance the capability of the technique - Time of Flight Secondary Ion Mass Spectrometry - ToF-SIMS. which, by bombarding the surface with moderate energy particles, analyses the surface chemistry of materials by removing and analysing molecular and atomic fragments. The research will take two directions. First we will capitalise on our exciting advances using bucky-ball (C60) and metal cluster beams to bombard the surface. These cluster beams remove molecules rather gently (ensuring that they are much less damaged in the removal process than under atomic beam bombardment), but in large quantities, enhancing sensitivity and analytical efficiency. Our research will seek to understand how these beams remove molecules from the surface, so that we can tailor their use to the samples to be analysed. This fundamental research will be augmented by some adventurous instrumental developments in collaboration with a small high technology UK company - Ionoptika Ltd. First, a totally new instrument uniquely combining ToF-SIMS and the complementary infra-red spectroscopy ATR-IR technique will be developed. Combining these two techniques in this new instrument will enable for the first time the surface chemistry and the sub-surface chemistry of complex biological, organic and inorganic materials to be studied at the same time. This is important because of the strong link between the surface chemistry of materials and their sub-surface or bulk chemistry. Second, we will incorporate tandem mass spectrometry into our ToF-SIMS. This facility enables the large complex molecules found in many materials to be selected and broken into smaller easily analysed fragments permiting accurate analysis of these molecules. Finally we will develop new ways of producing cluster ion beams that improves the focussing capability of the beams to enable analysis at high spatial resolution, so that the spatial chemistry of heterogeneous materials, eg biological tissue, cells, catlaysts etc can be characterised with high sensitivity.

Silicon based information technology has revolutionized the modern world. As device features have decreased in size, integrated circuits (ICs) have become subject to quantum mechanical phenomena. Quantum technologies aim to exploit these quantum mechanical phenomena to perform tasks that are difficult or impossible with conventional technologies. One of the main obstacles in developing quantum technologies is the rapid destruction of quantum superposition states caused by interference with the environment in a process called decoherence. Recently, extremely long coherence times (hours) have been demonstrated using small amounts of additives to silicon that have a "spare" electron (donor impurities). Although even longer times can be obtained for atoms in vacuum, an atom trapped permanently in a solid crystal such as silicon is much easier to handle. A major source of decoherence in solids is the nuclear spin of the atoms that make up the host crystals, as they often flop around uncontrollably. This has been eliminated by isotopically purifying the silicon (which normally contains a mix of isotopes, only a small number of which have nuclear spin). Even so, the donor impurities don't interact with telecoms wavelength light, and this is critical for many quantum technologies, quantum communication schemes in particular. There are currently no solid-state quantum technology platforms with long coherence times and optical fibre telecommunications compatibility. The optical transitions of the rare-earth atom erbium are, however, telecommunications compatible. Rare-earth ions are also ideal systems for quantum technologies because the shielding of their electrons offers an atomic scale barrier to decoherence. When doped into relatively high nuclear spin metal oxide crystals, rare-earths show coherence times comparable to donor impurities in natural silicon, but are yet to be investigated in silicon themselves. Ion implantation is a well understood technology used in today's silicon IC manufacture and history has shown that commercial interest in new technologies favours those relying on established fabrication platforms and techniques. Given the expected improvement in coherence time from using erbium implanted isotopically pure silicon, it should be possible to develop a quantum technology platform that has a long coherence time, and is telecommunications and conventional IC tooling compatible. Quantum computation schemes require the entanglement of quantum bits (qubits), this remains challenging in silicon based qubits but has been demonstrated in superconducting circuit qubits. As the latter has short coherence times and lacks optical addressability, I envisage a hybrid scheme where processing is performed with the superconducting resonators and erbium implanted silicon qubits are used as the quantum memory element and as a quantum transducer between telecommunications and microwave wavelength photons. Through this project I will introduce a new quantum technology platform to the research community: erbium implanted silicon. This platform combines the telecommunication capability of erbium and integrated circuit capability of silicon, making it valuable for both quantum computing and quantum communication applications.

Development of materials has underpinned human and societal development for millennia, and such development has accelerated as time has passed. From the discovery of bronze through to wrought iron and then steel and polymers the visible world around has been shaped and built, relying on the intrinsic properties of these materials. In the 20th century a new materials revolution took place leading to the development of materials that are designed for their electronic (e.g. silicon), optical (e.g. glass fibres) or magnetic (e.g. recording media) properties. These materials changed the way we interact with the world and each other through the development of microelectronics (computers), the world wide web (optical fibre communications) and associated technologies. Now, two decades into the 21st century, we need to add more functionality into materials at ever smaller length-scales in order to develop ever more capable technologies with increased energy efficiency and at an acceptable manufacturing cost. In pursuing this ambition, we now find ourselves at the limit of current materials-processing technologies with an often complex interdependence of materials properties (e.g. thermal and electronic). As we approach length scales below 100s of nanometres, we have to harness quantum effects to address the need for devices with a step-change in performance and energy-efficiency, and ultimately for some cases the fundamental limitations of quantum mechanics. In this programme grant we will develop a new approach to delivering material functionalisation based on Nanoscale Advanced Materials Engineering (NAME). This approach will enable the modification of materials through the addition (doping) of single atoms through to many trillions with extreme accuracy (~20 nanometres, less than 1000th the thickness of a human hair). This will allow us to functionalise specifically a material in a highly localised location leaving the remaining material available for modification. For the first time this will offer a new approach to addressing the limitations faced by existing approaches in technology development at these small length scales. We will be able to change independently a material's electronic and thermal properties on the nanoscale, and use the precise doping to deliver enhanced optical functionality in engineered materials. Ambitiously, we aim to use NAME to control material properties which have to date proven difficult to exploit fully (e.g. quantum mechanical spin), and to control states of systems predicted but not yet directly experimentally observed or controlled (e.g. topological surface states). Ultimately, we may provide a viable route to the development of quantum bits (qubits) in materials which are a pre-requisite for the realisation of a quantum computer. Such a technology, albeit long term, is predicted to be the next great technological revolution NAME is a collaborative programme between internationally leading UK researchers from the Universities of Manchester, Leeds and Imperial College London, who together lead the Henry Royce Institute research theme identified as 'Atoms to Devices'. Together they have already established the required substantial infrastructure and state-of-the-art facilities through investment from Royce, the EPSRC and each University partner. The programme grant will provide the resource to assemble the wider team required to deliver the NAME vision, including UK academics, research fellows, and postdoctoral researchers, supported by PhD students funded by the Universities. The programme grant also has significant support from wider academia and industry based both within the UK and internationally.