Speaker: Etienne Lantagne-Hurtubise, Université de Sherbrooke

Time: 1:00-2:00pm

Location: BRIM 311

Abstract: Rhombohedral graphene multilayers are clean and highly-tunable 2D materials that showcase a multitude of symmetry-broken insulating, metallic and superconducting phases at low temperatures. Their rich phase diagram can further be modified via proximity to transition metal dichalcogenides such as WSe₂, which induce spin-orbit coupling in the graphene layers and lead to a dramatic enhancement of superconductivity. I will first present Hartree-Fock phase diagrams for these systems, highlighting a spin-canted magnetic phase consistent with recent nano-SQUID experiments. I will then describe a pairing mechanism based on the low-energy collective spin modes (or magnons) associated with spin canting, which could explain spin-orbit-enhanced superconductivity in these systems. Finally, I will show how the valley-polarized superconductors recently reported in rhombohedral tetra- and penta-layer graphene could host superconducting collective modes accessible in linear optical spectroscopy.