  The emerging field of nano-magnonics utilizes high-frequency waves of
magnetization - the spin waves - for the transmission and processing of
information on the nanoscale. The advent of spin-transfer torque has spurred
significant advances in nano-magnonics, by enabling highly efficient local
spin-wave generation in magnonic nanodevices. Furthermore, the recent emergence
of spin-orbitronics, which utilizes spin-orbit interaction as the source of
spin torque, has provided a unique ability to exert spin torque over spatially
extended areas of magnonic structures, enabling enhanced spin-wave
transmission. Here, we experimentally demonstrate that these advances can be
efficiently combined. We utilize the same spin-orbit torque mechanism for the
generation of propagating spin waves, and for the long-range enhancement of
their propagation, in a single integrated nano-magnonic device. The
demonstrated system exhibits a controllable directional asymmetry of spin wave
emission, which is highly beneficial for applications in non-reciprocal
magnonic logic and neuromorphic computing.
