Superconductivity is universally (at least as far as we know) associated with the formation of Cooper pairs, arising from an effective low-energy attraction between the electrons. Nonetheless, the most spectacular realizations of the superconducting phenomenon occur in materials which are dominated by strong repulsive interactions, often refereed to as “strongly correlated materials“.
This surprising relationship is the key observation behind the properties of the high-temperature superconductors based on copper oxides, the cuprates. In this materials superconductivity appears doping a Mott insulator, a compound with a half-filled band which is however insulating because the strong Coulomb repulsion inhibits the motion of the carriers.
After the discovery of the cuprates it seemed that two distinct families of superconductors existed: standard BCS superconductors with phononic pairing and low critical temperataure and exotic high-temperature superconductors with a new “electronic” mechanism.
The discoveries of the last decades suggest that this distinction is not rigid, and materials can show intermediate properties. The SUPEBAD project aims to draw a complete picture of the superconducting phenomenon for compounds with strong correlations. To this end we explore most families of known superconductors, from the cuprates to the fullerene-based compounds, passing from the heavy-fermion materials and the iron-based pnictides and chalcogenides.