Spin-orbit-driven ferromagnetism at half moiré filling in magic-angle twisted bilayer graphene.

Strong electron correlation and spin-orbit coupling (SOC) can have a profound influence on the electronic properties of materials. We examine their combined influence on a 2-dimensional electronic system at the atomic interface between magic-angle twisted bilayer graphene and a tungsten diselenide crystal. Strong electron correlation within the moiré flatband stabilizes correlated insulating states at both quarter and half filling, and SOC transforms these Mott-like insulators into ferromagnets, evidenced by robust anomalous Hall effect with hysteretic switching behavior.