Étienne LANTAGNE-HURTUBISE : Rhombohedral graphene: A tunable platform for unconventional superconductivity and collective modes

Étienne LANTAGNE-HURTUBISE, Département de physique & Institut Quantique, Université de Sherbrooke

Le résumé :

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 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 magnon modes 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 exotic superconducting collective modes accessible in linear optical spectroscopy.