Magnetic insulators play an increasingly important role in spintronics and condensed matter physics. Although it does not conduct electricity, when a magnetic insulator is in proximity with a conducting material, it can induce interesting spin-dependent transport phenomena. In this talk, I will present several such phenomena at the interface of non-magnetic conductor and yttrium iron garnet or YIG. If the non-magnetic conductor has strong spin-orbit coupling, the spin current generation and reflection can cause a spin Hall magnetoresistance in addition to the anisotropic magnetoresistance. If the conductor is a single-layer graphene, the magnetic proximity effect at the interface of graphene/YIG induces ferromagnetism and spin polarization in graphene.
Ferromagnetic graphene is expected to exhibit unique ground states such as spin superconductivity and quantized anomalous Hall state. I will show our first demonstration of ferromagnetic graphene using the proximity effect approach and discuss the physical origin of the anomalous Hall effect.
Department of Physics and Astronomy, University of California, Riverside, USA