Superconductivity from spin-canting fluctuations in rhombohedral graphene

Rhombohedral graphene multilayers host various broken-symmetry metallic phases as well as superconductors whose pairing mechanism and order parameter symmetry remain unsettled. Strikingly, experiments have revealed prominent new superconducting regions in rhombohedral bilayer and trilayer graphene devices with proximity-induced Ising spin-orbit coupling. We propose that these superconductors can be triggered by critical fluctuations occurring near the onset of spin-canting order. In this scenario, contrary to conventional mechanisms that involve the exchange of a single boson, we show that second-order processes that exchange \emph{two} magnons are dominant and produce a pairing interaction featuring a unique logarithmic low-frequency divergence. This low-frequency divergence requires spin-orbit coupling, providing a promising explanation for spin-orbit-enabled pairing.