Non-local magnon transport in a magnetic domain wall wave guide

Magnetic domain walls function as a wave guide for low energy magnons. In this paper we develop the theory for the non-local transport of these bound magnons through a ferromagnetic insulator that are injected and detected electrically in adjacent normal metal leads by spin-flip scatting processes and the (inverse) spin-Hall effect. Our set-up requires a twofold degeneracy of the magnetic ground state, which we realize by an easy axis and hard axis anisotropy, in the ferromagnetic insulator. This is readily provided by a broad range of materials. The domain wall is a a topologically protected feature of the system and we obtain the non-local spin transport through it. Thereby we provide a framework for reconfigureable magnonic devices.