Heterostructures with atomically flat magnetic insulator thin films

Magnetic insulators have recently attracted a great deal of attention in condensed matter physics especially in spintronics community. For example, through proximity coupling, magnetic insulator can induce a ferromagnetic order in a non-magnetic material such as graphene or topological insulator and therefore breaks the time reversal symmetry which consequently causes novel phenomena such as the quantized anomalous Hall effect. Magnetic insulators, through spin wave excitations, can mediate and transmit pure spin currents over a much longer distance than conductors. In my talk, I will first present our recent progress in growing atomically flat magnetic insulator films with both in-plane and perpendicular magnetic anisotropies which can be used for building different heterostructures. Then I will show several phenomena we have recently investigated in these heterostructures: proximity coupling induced ferromagnetism in graphene, magnon-mediated current drag across magnetic insulators, and topological spin Seebeck effect.