Event Details

Understanding out-of-equilibrium phenomena at the interface between metals and magnetic insulators constitutes a step forward in the design of energetically-efficient spintronic devices. Advances in this area also enable the realization and experimental detection of new forms of collective behavior like spin superfluidity: nearly dissipationless, coherent spin transport mediated by topologically stable textures. In this talk, I will discuss this phenomenology in the case of amorphous or polycrystalline magnets. The key observation is that structural disorder in this class of materials can average out the effect of anisotropies inhibiting the onset of spin superfluidity. I will present a hydrodynamical description of the flow of angular momentum injected by spin accumulation in adjacent heavy metals. The theory is valid for a broad class of magnets with frustrated interactions, where spin currents are defined in terms of coherent rotations of a non-collinear texture. Their stability, ascribed to the topology of the emergent SO(3) order parameter, resembles the phenomenology of chiral superfluids like 3He-A or spinor condensates with ferromagnetic order.