Speaker
Mr.
Pablo Villar Arribi
(European Synchrotron Radiation Facility , Grenoble, France)
Description
Iron-based superconductors are multiorbital systems in which Hund's coupling plays a key role. Very recently [1], a divergence of the electronic compressibility has been found in simplified multiorbital models relevant for these compounds. This divergence leads to an instability of the system, which might enhance some boson-mediated pairing mechanisms relevant for superconductivity.
FeSe, the simplest iron-based superconductor, has a critical temperature of 8 K which becomes larger with increasing pressure, reaching a maximum value of 37 K around 9 GPa. Moreover, a monolayer of FeSe over a substrate of SrTiO3 has shown a critical temperature higher than 100 K. We have studied the electronic compressibility of the normal non-magnetic phase in FeSe bulk at different pressures and in a monolayer. The results [2] show that a divergence of the electronic compressibility is found in a model for this compound under pressure, following similar trends than the critical temperature, and that this phenomenon occurs in the frontier between a normal and an orbitally decoupled (“Hund's”) metal.
References
[1] Luca de' Medici, Phys. Rev. Lett. 118, 167003 (2017).
[2] Pablo Villar Arribi, Luca de' Medici, in preparation.
Primary author
Mr.
Pablo Villar Arribi
(European Synchrotron Radiation Facility , Grenoble, France)
Co-author
Dr.
Luca de' Medici
(Laboratoire de Physique et Etude des Matérieux, CNRS/ESPCI/UPMC, Paris, France)
