The ultimate goals of volcanology are to understand and predict volcanic eruptions. A major challenge for volcanologists is to figure out what is happening inside volcanoes even though we can only watch and make measurements at the top. Laboratory experiments can bridge this gap because it is possible to see and measure flow within a model volcano at the same time as record vibrations caused by the flow that are equivalent to vibrations measured by real volcano monitoring. The proposed project takes this approach to study how gases escape from volcanoes, and how the abundance of gas and flow patterns inside the volcano can be assessed from acoustic signals (sounds) measured with microphones. Volcanic eruptions come in all sorts of styles from lava flows pouring out the top, to brief events from large bubbles bursting, to continuous fountains of drops of magma, to highly explosive eruptions with fragments traveling upwards in columns many kilometres high. Gases provide the main driving force for volcanic eruptions and the various types of eruptions have been explained using the framework of gas-liquid flow patterns observed in laboratory experiments by engineers. However, the work by engineers has been motivated by industrial flows with liquids that have a much lower viscosity than magma (that is, the liquids flow much more easily) and they have run experiments in tubes that are much smaller than conduits in volcanoes. So it is difficult to properly apply the engineering results to volcanic flows. This project will bring together volcanologists and engineers to run experiments at conditions relevant to volcanic eruptions. In particular, we will use air and syrup as analogues for volcanic gases and melt, and will observe flow patterns and bubble geometries for a variety gas flow rates, tube sizes and syrup viscosities. This will help us to understand the origins of the different eruption styles. The second phase of the project will investigate the physics of sound generation by gas motion and bubble bursting. Sounds, mostly at frequencies below what we can hear (infrasounds), are produced by all styles of volcanic activity and are thought to be related to gas bubbles and gas flow. Basaltic volcanoes produce some of the most interesting infrasounds because bubble merging (coalescence), bubble rise, and gas separation from the surrounding liquid (segregation) are all easy because basalt has a low viscosity compared to other types of magma. This means that there is potential to figure out important information on the gas flow inside basaltic volcanoes from infrasounds. The sounds produced by the air-syrup flow experiments described above will be recorded with microphones so that we can link flow patterns and bubble properties to the volume and pitch of the sounds they generate. An additional goal is to test if we can effectively use infrasound recordings as a tool to measure how much gas is moving through volcanoes. This is important because gases drive volcanic eruptions and play a key role in controlling eruption style and intensity. Infrasonic monitoring has huge potential because it is cheap and easy to use compared to other methods for measuring gas outputs from volcanoes. Systematic understanding of how infrasonic measurements made at volcanoes are related to the gas fluxes emitted will allow the full potential of this monitoring technique to be realized. Finally, we will use the results of the experiments and theoretical work to interpret infrasounds produced by basalt eruptions at Stromboli and Etna volcanoes in Italy. We will, for instance, evaluate whether small volcanic explosions result from the bursting of large individual bubbles or whether the explosions are the bursting of clouds of bubbles. We also anticipate gaining useful information from more subtle sounds or infrasounds that we don't already know about because the experiments will tell us what to look for in the volcanic acoustic data.

A quantum fluid is an unconventional type of fluid (gas or liquid) with exotic properties that can only be explained invoking quantum mechanics. For example, a quantum fluid possesses an inviscid component called superfluid component, whose percentage tends to 100% in the limit of very small temperatures (around the absolute zero); such property makes a very cold quantum fluid moving almost forever as viscosity, causing a classical fluid like water or honey to slow down in time, tends to zero. Another striking property of the superfluid component is the ability to host vortices (regions where the fluid rotates) that have only discrete values of circulation, in other words meaning that their strength is quantised. Despite being discovered about a hundred years ago when cooling down liquid helium at very low temperatures, most of the quantum fluids known today have only been experimentally realised in the last two decades. Their technological uses are still very limited but promising, as it is believed that in the next decades they could be used more and more to make incredibly precise sensors, in quantum computing, and as very efficient media to transport heat. However, in order to achieve these goals, a better understanding of their properties is of paramount importance. This proposal aims at better understanding quantum fluids characterised by strong interactions like for example, cold liquid helium. Due to their strong interactions, standard theoretical methods like perturbative methods fail to provide models for such systems. We propose to tackle the modelling by using a theoretical framework developed in the past two decades in the field of high energy particle physics and string theory called holographic duality / holography theory. In a nutshell, holography allows to find a model description of strong interacting systems by mapping them into weakly interacting systems at higher dimensions in curved space-time. This method certainly increases the complexity of the problem but allows to apply standard perturbative methods within the weakly interacting counterparts. More precisely, theoretical and numerical approaches can be attempted, therefore allowing to effectively model strongly interacting systems. The holographic duality has been applied to a great variety of physical systems in condensed matter and particle physics, including quantum fluids before. However, only in the last couple of years, dynamical modelling of quantum fluids have been feasible thanks to the development of novel numerical methods and the improvement of computational power. The proposed research will greatly extend these works and allow to model systems which are more relevant to experimental setups and discover, hopefully, new physics!

Topology is a branch of mathematics that describes properties of objects that remain robust under smooth deformations. Landmark discoveries in the field of condensed matter physics over the past four decades, recognised by three Nobel prizes in 1985, 1998 and 2016, have shown that certain materials in the regime of the fractional quantum Hall effect can exhibit similar insensitivity to external perturbations. This "topological" robustness underpins many remarkable properties, for example dissipationless currents circulating along the boundary of the material sample, while the bulk hosts novel quasiparticle excitations that behave as neither fermions nor bosons. These exotic properties could be harnessed to make ultra-low power electronic devices, and they could revolutionise the burgeoning field of quantum computing by shielding the computation from unwanted sources of errors. This proposal brings together a new UK-Ireland team of theorists, with experimental Project Partners at UCL and LENS (Florence, Italy), tasked with revealing the true nature of fundamental quasiparticle excitations of topological quantum matter. Our hypothesis is that these particles are "partons", i.e., fractionalised electrons with rich geometrical properties that emerge from strong interactions and quantum effects present within the topological material. In ordinary circumstances, partons are tightly bound within the constituent electrons of the topological matter, hence they have remained invisible to previous experiments. However, when the material is taken out of its equilibrium state, partons can exhibit observable signatures, which we will elucidate. The overarching goal of this proposal is to establish a new UK-Ireland partnership for topological quantum matter out of equilibrium. We will employ the emerging quantum technologies, such as quantum simulators made of ultracold atoms in optical lattices and digital quantum computers, as "parton accelerators": by exciting topological matter to high energies, we will study partons via their characteristic imprints on the dynamics of the system. We will develop state-of-the-art numerical simulations of fractional quantum Hall systems based on partons, and we will ultimately formulate an effective quantum field theory for describing topological quantum matter based on partons. The success of our objectives will advance the understanding of nonequilibrium properties of topological materials, which is key to their applications as platforms for fault-tolerant quantum computing. It will also pave the way towards an experimental observation of a new kind of particle that emerges from the interplay of strong correlations and geometric fluctuations in quantum materials, which will impact diverse condensed matter systems including fractional Chern insulators, quantum spin liquids and twisted van der Waals materials. Our use of quantum simulators for observing real-time dynamics of partons will boost the impact of results across a broad spectrum of synthetic matter platforms that are increasingly used for studying many-body phenomena outside of solid state materials. Finally, through collaboration with visual artists and by developing pedagogical workshops that target pupils in areas of low progression to higher education, our suite of public engagement activities will raise the profile of topology and quantum matter among the general public.

Context Many micro-vascular related diseases, such as those associated with diabetes, ischemia and cancer, exhibit changes in the micro-vascular structure and blood-flow. The measurement of micro-vascular morphology and changes in blood flow dynamics is therefore essential for early diagnosis and monitoring. Current clinical imaging modalities cannot adequately resolve the microvasculature or flow dynamics at clinically useful depths. The proposed work would generate three-dimensional (3D) super-resolved ultrasound vascular imaging and velocity mapping at clinical depths in vivo. We have successfully demonstrated that single microbubble localisation can produce acoustic super-resolution and super-resolved flow velocity images in vivo from standard image data acquired by an unmodified clinical ultrasound system using simple post-processing localisation algorithms. We achieved visualisation and velocity measurements of vessel structures below 20 micro-metres in vivo. Our present work is limited by the underlying two dimensional acquisition strategy; this means that there is no super-resolution information in the third dimension. We propose to overcome this by incorporating recent advances in US imaging technology in order to push beyond the established resolution limits of ultrasound imaging to translate this approach into a clinically useful imaging modality. Aims and Objectives Our objective is to develop 3D ultrasound super-resolution imaging of the microvasculature at depths of up to 10 cm with acquisition times that are clinically useful. We aim to be the first group in the world to demonstrate this in humans. To facilitate this transition, we will develop and implement fast 3D super-resolution acquisition strategies and protocols using a combination of compounding strategies with currently available US technology and ultrafast volumetric imaging using dedicated ultrasound matrix array technology. We aim to develop optimised and automated processing algorithms which will enable more precise and efficient image acquisition. Throughout our project, we will demonstrate 3D super resolution imaging and super-resolved velocity mapping using in vitro phantoms and in vivo models, and finally provide 3D super-resolved vasculature images in human studies. Potential Applications and benefits The proposed work is essential for clinical translation of super-resolution ultrasound imaging. The new 3D super-resolution imaging method could underlie next generation techniques for ultrasound measurement of the structure and function of the microvasculature. A non-invasive, safe, microscopic assessment of the vasculature could prove crucial to diagnosis, prediction, and intervention in a wide range of diseases.

Femtosecond lasers produce pulses of light which are extremely short and at the same time extremely powerful. The intensities available when light from such a laser is focussed down are capable of modifying the structure of transparent materials or even ablating material from the surface. We have developed an understanding of the interaction of fs laser pulses with optical glasses so that, depending on the pulse parameters, we can create light waveguides, couplers, bends and grating structures or even machine the surface to alter its topology on a micron scale. In this project we wish to bring these capabilities together to create a generic plasmonic sensing technology. Surface plasmons are oscillations of the free electrons in a thin metal film and these can be generated using the energy from light travelling in a waveguide close to the metal film. Importantly, the transfer of energy from the light to the plasmon only occurs at a well defined wavelength which depends strongly on the refractive index in a micron thick region above the metal film where the electric field of the plasmon extends. By sending a broad spectrum of light though the waveguide near the metal film and noting which wavelength is absorbed by the device it is possible to measure the refractive index above the metal very accurately. If chemical or biochemical specific coatings are applied to the metal film then the sensor can detect specific species. In this proposal we plan to investigate the use of aptamers in this regard. Aptamers are oligonucleotide sequences, which can be designed to bind to specific molecules, proteins, DNA sequences or even cells, providing a highly flexible sensing technology. An additional application for the technology is as a means of monitoring cell movement and growth. Cells contact a surface at specific points and if a cell is placed on the plasmon supporting metal film, light will be scattered from the plasmon field at the points of contact. This light may be viewed using a microscope which will allow the movement of the cells to be tracked over time. Cells respond differently depending on surface topology and the fs laser can be used to modify the sensor surface to enable studies of the effect of different surface topologies on cell movement and growth.