Final Report Summary - USED (Ultrafast Spectroscopic Electron Diffraction (USED) of quantum solids and thin films)
A cornerstone in the solution of the challenges faced by modern technology is the ability to understand and control materials properties at their atomic level. Microscopy techniques have been developed over the years and allowed obtaining spectacular images of matter and its constituents down to the single atoms. However, a key advance is the ability not only to image atoms but to actually see them move, as their coordinated dance induces phase transitions or promotes exotic phenomena in materials such as superconductivity. This requires techniques that combine atomic resolution in space and femtosecond (10^-15 seconds) resolution in time. One of the most powerful tools in this respect is the recently developed fs Transmission Electron Microscope, which allows to take fs snapshots of materials with the atomic resolution guaranteed by high-energy (200 KV) electrons. In this project, we successfully implemented an ultrafast TEM based on a new design that enables unprecedented time resolution and sensitivity to magnetic contrast. Thanks to this instrument, we could take a snapshot of light itself revealing its quantum and classical nature simultaneously. This result was obtained by confining an electromagnetic field on the surface of one single nanowire and imaging its properties in space and energy. Furthermore, the spatial distribution of magnetic objects called skyrmions, of interest as quantum information carriers, could be imaged revealing its symmetry.