Charles Tschirhart: Electrical switching of magnetic order in intrinsic Chern insulators

Title: Electrical switching of magnetic order in intrinsic Chern insulators

Abstract: A variety of intrinsic magnetic Chern insulators have been discovered in moiré superlattice systems, including in both graphene and transition metal dichalcogenide heterostructures. Unlike in previously
discovered magnetic Chern insulators, fabricated by adding magnetic dopants to thin films of topological insulators, these systems have magnetism supported entirely by electronic interactions intrinsic to the
topological bands. This fact helps limit disorder in these systems by removing the need for magnetic dopants, but it also intimately ties the magnetic order to electronic properties of the system, and thus facilitates electronic control of magnetism. I will discuss electronic switching of magnetization in Chern insulators through two different mechanisms: topological contributions to magnetization and intrinsic spin-orbit torques. I will discuss these mechanisms in the context of twisted bilayer graphene, twisted monolayer/bilayer graphene, and AB-MoTe2/WSe2 using transport measurements and magnetic imaging performed with our nanoSQUID microscope.