Density hysteresis and spin canting in rhombohedral trilayer graphene

Abstract Spontaneous symmetry breaking leads to ordered phases, and hysteretic behavior often serves as a hallmark of emergent thermodynamic properties. Charge-neutral rhombohedral few-layer graphene is a strongly interacting system prone to layer antiferromagnetic (LAF) insulators, owing to its nearly flat bands with a high topological winding number. Here, in ultra-clean rhombohedral trilayer graphene devices—suspended to maximize interaction effects—we observe unexpected yet reproducible density hysteresis centered at the charge neutrality point (CNP), both at zero and finite electric fields. This hysteresis accentuates under an applied in-plane Zeeman field, but gradually weakens and eventually disappears as the temperature increases from 10 mK to 500 mK. These observations highlight the many-body nature of the LAF state, indicating a discontinuity in the chemical potential at the CNP and Zeeman field driven noncollinear spin canting. Our findings broaden the understanding of correlated phenomena in rhombohedral graphene and demonstrate both electric and magnetic control over antiferromagnetic order.