Direct Electron Detection Camera for Next-Generation Sensitivity in Ultrafast Electron Scattering Measurements

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There is currently an enormous, worldwide effort directed at the development and application of new experimental methods that make it possible to directly `watch' the time evolving structure of matter. These approaches combine state-of-the-art femtosecond lasers (see Nobel Prize in Physics, 2018) and sources of either ultrashort xray or electron pulses to acquire time-resolved diffraction/scattering patterns and images. If time-resolution approaches ~10 femtoseconds, the timescale of the highest frequency vibrations in molecules and materials, atomic motion is essentially frozen during an observation and one can completely follow the fundamental dynamics to produce a "molecular movie"; the experimental equivalent of a molecular dynamics simulation. It is possible to watch chemical bonds break/form and directly determine transition-state structures for even complex reactions, to follow phase transition dynamics uncovering the deep connections between the structure and properties of materials, and directly observe the coupling between charge, orbital and lattice degrees of freedom in both momentum and time. This proposal is focused specifically on the further development of the World's most powerful ultrafast electron scattering instrument, designed, built and operating at McGill University. We are requesting a state-of-the-art direct electron detection camera to replace our existing obsolete detector, enhancing our detection sensitivity by at least an order of magnitude.  This new capability will open up a significant new 'scientific space' of phenomena that are undetectable with our current camera, shedding new light on materials phenomena as diverse as superconductivity, charge density waves, thermoelectricity, photovoltaicity and carrier mobility in semiconductors and metals. We will be in a position to investigate the complex interplay between strong, multiorbital electronic correlations, structural distortions, charge and orbital order across a range of strongly correlated material where this physics determines properties (transition metal oxides, pyrochlore oxides, manganites and cuprates), including the formation dynamics of quasiparticles in these systems that involve phonons.  In monolayer and bilayer materials we will be able to direct watch exciton-phonon and exciton-polaron coupling, and chiral phonon generation.  Further, there is also the possibility of discovering new photoinduced phases and avenues for optical control of complex materials, a topic at the forefront of materials research.