Speaker
Description
Narrow bands in graphene moiré heterostructures can host magnetic electronic states in which electrons become spontaneously valley-polarized due to strong electronic interactions. These magnetic states include both gapped states at integer superlattice fillings that manifest the quantized anomalous Hall effect (QAHE), and metallic states that exhibit the anomalous Hall effect (AHE) at intermediate fillings. A ubiquitous feature of such magnetic states is the presence of magnetization reversal points, where the magnetization changes sign as a function of chemical potential, displacement field, or other control parameters. Such reversal points enable non-volatile electrical manipulation of the magnetic states, providing a useful control knob for potential devices based on AHE or QAHE phases.
Proximity-induced spin–orbit coupling provides a promising route to engineer the magnetic properties of graphene moiré systems, as it controls the interplay between the orbital and spin contributions to the magnetization. I will present a systematic study of gapped and metallic ferromagnetic states in twisted monolayer–bilayer graphene (tMBG) devices proximitized with WSe₂. I will discuss the details of the onset of the quantized anomalous Hall plateau in these devices. Finally, I will examine how proximity-induced spin–orbit coupling affects non-volatile electrical switching in this system.