EQuAL Seminar: Trevor Arp

Orbital Magnetism in Graphene Multilayers

Graphene was the first two-dimensional material to be isolated, yet remains full of new physics. Recent work has focused on rhombohedral graphene (RG) multilayers, composed of a few layers of graphene in the ABC stacking order because they exhibit magnetism, unconventional superconductivity, and topological states in a controllable and reproducible material platform. A ubiquitous phenomenon in RG is orbital magnetism arising from the geometry of electron wavefunctions. Using nanoSQUID-on-Tip microscopy to probe the micro-magnetism fo RG with nano-Tesla resolution I will reveal the rich dynamics of orbital magnetism including strong ferromagnetism, intervalley coherence, domain dynamics, and hysteresis, across trilayer and pentalyer RG. I will discuss how this type of magnetism arises, what surprises it has given us, and what it means for graphene’s unconventional superconductivity.