Gregorio Ponti, UT-Austin

“Investigating Superconductivity in Intermetallics”

Abstract: Since its discovery in 2008, high-temperature superconductivity in iron-based compounds has been an intense focus for the superconductivity community to understand the nature of this new class of compounds. Their normal and superconducting phase properties vary from the standard electron-phonon coupled “conventional” superconductors, requiring the application of a new pairing mechanism to explain their superconducting state. In this talk, we shall go over conventional BCS theory of superconductivity, and its failures in describing the iron-based superconductor (IBSC) system. The most common of the suggested pairing mechanisms (s±-wave) will be explained with reference to the simplest of the IBSCs: the ‘11’ iron chalcogenides (FeCh). With this background, I will then go over our group’s recent experiments of the ‘11’ structure, mixed chalcogenide superconductor F1+εTe0.5Se0.5 (0 ≤ ε ≤ 0.15), their shortcomings and the need to further investigate the system. I conclude with future directions of investigation for IBSCs and other closely related systems.