Prof. Massimo Capone, Strongly Correlated Superconductivity: Toward a unified Framework

     Prof. Massimo Capone, International School for Advanced Studies (SISSA) and CNR-IOM, Trieste

The discovery of high-temperature superconductivity in doped Mott insulators like the cuprates, has established a surprising link between electron pairing and the strong repulsive interactions responsible of the Mott phenomenon. We discuss how this class of strongly correlated superconductors can be extended to include besides cuprates also organic materials (fullerides, aromatic conductors) and the iron-based superconductors.   

Using Dynamical Mean-Field Theory (DMFT) to solve a three-orbital model with realistic interactions, we show that the same correlation effects play a central role also in iron superconductors and in fullerides. In the latter family Cs3C60 is indeed a Mott insulator and turns into a superconductor under pressure. We show that despite the phononic nature of pairing, the proximity to the Mott state favours superconductivity also in this case [1]. In iron pnictides orbital selectivity and the correlations properties are controlled by the distance of a Mott insulator, which would be realized for a doping of one hole per iron [2] leading to a surprising correspondence between them and the cuprates. The three families of superconductors fit therefore in a single picture regardless the nature of pairing.  

This work is financed by ERC through the SUPERBAD project (G.A. 240524).   

[1] M. Capone, M. Fabrizio, C. Castellani and E. Tosatti, Rev. Mod. Phys. 81, 943 (2009).

[2] L. de' Medici, G. Giovannetti and M. Capone, Phys. Rev. Lett. 112, 177001 (2014).