This project links the advancing technology of quantum computation, with the fundamental theory of phase transitions in physical systems. Quantum computers use qubits, which utilise a quantum property known as entanglement. Subsequently, quantum computers can perform tasks that classical computers are physically unable to do. Utilising this, quantum computers can be used to witness quantum energy teleportation which is a strictly quantum mechanical effect, therefore classical computation is unable to witness this. The benefit of witnessing quantum energy teleportation is that there is an apparent link between the energy teleported and the corresponding phase transition of the system. The phase transition clarifies the point at which a system undergoes a change in physical behaviour. It is important to understand how physical systems change, as certain phases may provide technological benefit, therefore being able to predict and understand them is of both fundamental and practical interest. Combining both, the application of quantum computation using quantum energy teleportation, and developing our understanding of phase transitions is the focus of this project. This will be done by computing the quantum energy teleportation for various well-known physical systems, and comparing the results with the known phase transition points. An additional point of interest, is to study these two phenomena from the perspective of quantum information, specifically focusing on how 'quantum' these physical systems are, and how the quantum correlation evolves throughout the process. In particular, a type of quantum correlation will be studied known as quantum discord. This will be compared with entanglement entropy as this also believed to be a good witness of phase transitions. Quantum discord is more general than entanglement, so it is believed that that discord should also be a good witness for phase transitions. This project will also look to link and develop the link between quantum energy teleportation, entanglement entropy, and quantum discord. It is of national interest to understand and quantify quantum correlations, as this will help develop materials which can utilise the advantage gained from quantum correlations. Subsequently, the aim of this project is to further the current understanding of phase transitions using quantum technologies with an added focus of developing the theory of quantum correlations.

Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.

The oxygen we breathe and the food we eat ultimately derive from photosynthesis, the conversion of the sun's rays into useful chemical energy by plants and bacteria. However, we can have too much sunshine. Just as humans can suffer from skin cancer due to harmful UV rays in the sun, so plants and bacteria can be damaged by too much sunlight. As a result of these conflicting demands it is essential for a wide range of living organisms to have some means of sensing light levels. That plants have such tools is obvious to anyone who has ever grown cress on a windowsill and seen it turn towards the light. What we are principally concerned with in this project is precisely how plants and bacteria sense light, and whether this process can be exploited in human applications. In this proposal we focus on one particularly useful family of photosensor proteins, the LOV (Light-Oxygen-Voltage) domains. Over the past twenty years many proteins have been discovered which detect light. The LOV domain proteins are part of a much larger group called the flavoproteins. 'Flavo-' means yellow indicating that these proteins are colored and thus have the ability to absorb light energy. In the photoactive flavoproteins, which includes the LOV domains, this energy is converted it into some useful structure change in the protein. This then stimulates further changes in associated proteins which ultimately gives rise to a specific biological response. This complex chain of events in known to be important in: determining when flowers open; making leaves turn towards the sun; causing bacteria to swim away from harmful sunlight; controlling circadian rhythms, etc. In a few cases the structures of these LOV domain proteins have been determined, and other experiments have shown what secondary proteins (or DNA) they are complexed with, which informs us about their function. However, very little is known about the mechanism of operation of photoactive flavoproteins, beyond the fact that the proteins binds a flavin molecule which absorbs blue light. The question at the heart of our research is how is the event of light absorption can be converted into a specific structure change which acts as a signal to initiate other processes in living cells. In this work we will use some of the most sophisticated methods of laser spectroscopy to record what happens to the proteins after they have absorbed light. It is through the application of such advanced physical methods to living systems that we can begin to understand (and even control) the chemistry of life. In this case we will stimulate the protein response with a short pulse of blue light (less than 100 million billionths of a second long) and use another short pulse of light to take ultrafast 'snapshots' of the structural changes as they happen. We will follow these structure changes right from the time of excitation all the way through to formation of the final signalling state. By thus observing protein function in real time we will obtain new insights into the mechanism of how plants 'see' light. We will then use some tricks of protein chemistry to test, probe and manipulate these structure changes. Our interest in these proteins is not simply curiosity as to how they work. Recently scientists have artificially incorporated light-activated proteins into various cells and then used light to trigger a particular response. The most famous example is the use of light to activate the firing of neurons in the brains of mice, but as other light-activated proteins (such as LOV domains) become better understood it will become possible to stimulate a variety of new phenomena. The ability to stimulate a specific process in a living cell with both time and space resolution will represent a powerful new tool for scientists trying to understand cellular functions, and will inform a variety of research in health sciences.

A detailed understanding of the innate workings of the cell is imperative for our prospects of making new advances in the treatment of infections and disease. How the cells of our body respond to stresses ranging from cancer to the common cold is all highly sought knowledge. To help reveal this information we intend to design a range of small chemical compounds which can get into the cells and shut down the function(s) of specific proteins in order to observe the effects on the cell and reveal the role of specific proteins in cell maintenance. This can be achieved by using chemicals which mimic the ones the proteins normally work with and use them to distract the protein from doing its proper job. We want to mimic sugar nucleotides (sugar-NDPs).Sugar-NDPs are the building blocks used by a class of intracellular biocatalytic proteins know as glycosyltransferases (GTs). GTs biosynthesise oligosaccharides and glycoproteins which are central players in cellular function and maintenance. Sugar-NDPs carry some 'fat-repelling' negative charge which stops them from escaping the cells' watery innards through the greasy cell membrane, but also prevents the delivery of sugar-NDP mimics into the cell. The ability to prepare uncharged sugar-NDP mimetics which can ultimately diffuse into cells and perturb the function of specific GTs would be extremely desirable. We will develop synthetic chemical methods that will facilitate the preparation of such sugar-NDP-like compounds by replacing the negatively charged component of the sugar-NDP (ie. the pyrophosphate group) with a sugar molecule. The sugar should be able to mimic the missing pyrophosphate component and also help to make the sugar-NDP mimic more greasy. This will increase its chances of getting into get into the cell across the greasy cell membrane to do the job at hand. Current methods for synthesising such molecules can be particularly challenging and time consuming. However we will design a selection of simple chemical building blocks that be chemically 'clipped' together in different combinations so that it will be possible to prepare a range of uncharged sugar-NDP-like structures in a less labour intensive manner.

The internal behaviour of the Earth is controlled by convection hence knowledge of mantle viscosity is critical to our understanding. The viscosity of the mantle on large scales has been measured from post-glacial rebound and geoid inversions. These have shown that there is a significant contrast in viscosity between the upper and lower mantles which has been invoked to explain the varied behaviour of subducting slabs at the 660 km discontinuity. The slabs show a range of behaviour from ponding just above the 660 km discontinuity to penetrating the discontinuity and thickening as they enter the lower mantle. It is apparent therefore that the size and impermeability of the 660 km viscosity contrast affects the style of mantle convection and cooling rates but the resolution of the geophysical observations is not sufficient for a complete understanding of the fate of material around the 660 km discontinuity. Here we propose to measure the rheology of the minerals and assemblages present in the transition-zone and lower-mantle and so provide the constraints needed for a fuller understanding of the viscosity contrast between the upper and lower mantles.