FIS: two projects by Politecnico di Milano funded

Thanks to abovEF, it will be possible to set up a totally new laboratory for the study of electronic states of quantum materials. By using inverse photoelectron spectroscopy with unprecedented energy and momentum resolution and by combining it with the better-established angle-resolved direct photoelectron spectroscopy, it will become possible for the first time to observe the details of electronic bands of solids across the Fermi level. The main novelty is in the observation of empty states above the Fermi level. In fact, together with the states lying below the Fermi level, which are populated by electrons, they determine the electronic and magnetic properties of materials. However, to observe empty states it is necessary to populate them with electrons in a very controlled way, which is technically very difficult.

The inverse photoelectron spectroscopy was invented several decades ago, but was mostly abandoned in the recent years due to the unsatisfactory quality of the measurements caused by the exceptional technical difficulties of the method. The aboveEF project aims at improving by 10 times the energy resolution and by 100 times the sensitivity of the instrument for inverse photoelectron spectroscopy with respect to the present state of the art, gaining unprecedented quality in the experiments. Virtually any classes of materials can be studied with this technique, but the project will particularly focus on two-dimensional quantum materials and high critical temperature superconductors.