IQIM Postdoctoral and Graduate Student Seminar

Abstract: Multilayer graphene provides an ideal setting for studying correlated electronic phenomena due to its tunability and cleanness. This system hosts superconducting (SC) phases alongside various symmetry-breaking orders arising from electron-electron interaction. However, the origin of these SC phases and their connections to such orders remain puzzling. In this talk, I will start by discussing a testable signature that indicates some of these SC phases originate from fluctuation of order parameters. I will then describe a pairing scenario motivated by this finding and other measurements, aiming to explain the main SC phase observed in bilayer graphene proximity coupled to WSe2. In this scenario, the gapless magnon emerging on top of a symmetry-breaking order takes on the role of a pairing glue. This scenario highlights the qualitative importance of the spin-orbital coupling, explaining the observed order-10 enhancement of Tc by the proximate WSe2 layer. Furthermore, it naturally accounts for many other observations on this SC phase, including the sensitivity to fermiology, the dependence on an applied magnetic field, and a peculiar behavior of the Pauli-limit-violation ratio, which, to the best of my knowledge, cannot be understood within other scenarios.

Lunch will be provided, following the talk, on the lawn north of the Bridge Building.