Richard SCHLITZ
A key research focus in the field of magnonics is the study of electrically generated and detected pure (magnon) spin currents in heterostructures of a magnetic insulator and a heavy metal. Careful device design enables the investigation of the spin transport via magnon diffusion in magnetic insulators. However, the absence of the magnon equivalent of an electric force is an obstacle for realizing the full potential of pure spin currents. In this work, we report the controlled generation of magnon drift currents in heterostructures of yttrium iron garnet and platinum. Relying on the electrical injection and detection of incoherent magnons, we find magnon drift currents that stem from the interfacial Dzyaloshinskii-Moriya interaction. By changing the orientation of the magnetic field, we can control the magnon drift, where a maximum change of the magnon propagation length by up to ±6% relative to diffusion can be achieved. Good agreement between experiments and an extended spin transport theory which includes a finite drift velocity resulting from any inversion asymmetric interaction is found.