Accueil > Groupes de recherche > Physique des solides > Equipe "Matière Condensée et Irradiation : du Fondamental au Fonctionnel" > Strongly correlated systems and new electronic states of matter
In systems with strongly interacting fermions, the competition between the different degrees of freedom leads to competing quantum ground states, from which a rich variety of macroscopic phenomena emerge. In many cases, these phenomena arise from phase transitions described by exotic (or even unknown) order parameters and underlying novel states of matter. As such, the physics of strongly-interacting fermions is the common thread in several challenging open problems. For instance, such physics is involved in the description of compact nuclear and sub-nuclear matter, in the study of the primitive Universe and the symmetry breakings leading to today’s observable cosmos, in ultra-cold atomic gases in optical lattices, or in electrons in solids composed of rare-earth elements or transition-metal oxides. These classes of materials are the subject of our research. They present stunning properties, such as superconductivity, exotic magnetic states, multi-ferroic behavior, photo-catalytic capacity, or exotic quantum phase transitions under the influence of an external field, pressure or doping.
To understand the remarkable properties of such materials, the most direct, experimental approach is to study their quantum band structure and how the many-body interactions and phase transitions affect it. The technique of angle-resolved photoemission spectroscopy (ARPES), that we use in our group, does precisely that. ARPES gives access to the band structure, the effective masses and the scattering-rate of electrons (hence the effects of many-body interactions) in the occupied states of the solid. This technique has been successfully used over the past 30 years in the study of many strongly correlated electron systems.
Contact : A. Santander-Syro