Angle-resolved photoemission from tailored mesostructures

Angle-resolved photoemission (ARPES) is one of the most powerful probes of electronic structure and many-body interactions in solids [1]. Recent advances in the focusing of synchrotron radiation have opened the possibility for performing modern ARPES measurements from micron-sized spatial regions, advancing a completely new form of “spectro-microscopy” [1-3]. Similarly transformative advances come from recent developments in focused ion and electron beam techniques, allowing materials to be sculpted to mesoscopic length scales to bring them into new regimes [4,5] for the study of transport, many-body interactions, and topological phenomena. In this project, you will combine these approaches, fabricating tailored micro- and meso-scale structures and using spatially-resolved photoemission to study their electronic states. In the past, large single crystals were required for ARPES, but this new approach will circumvent that restriction, and make electronic structure measurements possible from a huge variety of new materials systems. In addition, it will allow new possibilities for control, for example probing the evolution of the electronic structure under current flow or with tailored strain gradients.    The project will make use of the state-of-the-art clean room and nanofabrication facilities at MPI-CPFS, as well as capabilities for spatially-resolved ARPES measurements in St Andrews and at leading national and international synchrotron light sources. Topics of initial interest include high-conductivity oxide metals, although the potential scope for new materials exploration is very high.