Prof. Enrico Rossi
Department of Physics
William & Mary

Abstract

Superconductivity is one of the most striking macroscopic manifestations of quantum mechanics. In recent years strong superconductivity has been observed in systems in which the electrons behave as extremely heavy particles, i.e., have a very large effective mass. This is somewhat surprising given that the conventional theory of superconductivity predicts that the ability of a system to carry a supercurrent decreases as the effective mass of the electrons increases. In this talk I will discuss how robust superconductivity can be present even in systems in which the effective mass of the electrons is infinite due to an additional contribution to the superconducting density, that was neglected by the conventional theory, arising from the quantum metric of the electronic states. I will then discuss the relevance of this contribution for systems like twisted bilayer graphene.