Unveiling the nature of superconductivity in moiré quantum matter

ongoing

Graphene moiré materials constitute a new paradigm in condensed matter physics for the study of superconductivity and other collective electronic phases given their chemical and structural simplicity as well as large tunability as compared to other many-body systems. However, a comprehensive picture of the fundamental properties of superconductivity in graphene moiré materials is still missing due to the limited information attained so far at the microscopic level. Therefore, the need for local probe techniques that enable the exploration of superconductivity in moiré matter with outstanding energy and spatial resolution is pressing, and constitutes the main motivation of this project. The ultimate objective of this project is to unveil the microscopic mechanisms driving superconductivity in graphene moiré materials. To this end, I propose the local characterization of the superconductivity in various twisted graphene systems with unprecedented resolution (few µeV) by means of STM/STS measurements at milikelvin temperatures. Here I aim to unveil (i) the symmetry of the order parameter(s) in unambiguous connection with the valley, orbital and spin degrees of freedom, (ii) the origin(s) of the attractive interactions governing Cooper pairing, and (iii) the nature of the neighboring correlated phases as well as their interplay with the superconducting state. The intellectual merit of this project lies in the fact that will provide ground-breaking insights to long-standing questions in condensed matter physics, initially posed in complex unconventional superconductors, here instead tackled using simple, highly tunable moiré materials. Furthermore, this project has the potential to unveil forms of superconductivity never seen in nature before by using state-of-the-art microscopy technology that combines atomic-scale spatial resolution with the finest energy resolution.