Slow-Wave-Based Nanomagnonic Diode

Nonreciprocal wave propagation is important for signal processing and wave-based computing, but has not been realized in spin-wave devices. The authors engineer such nonreciprocity for spin waves in a transversely magnetized ferromagnetic bilayer so that the waves completely stop in one direction while still propagating with significant velocity in the opposite one. Electrical and optical measurements are combined with analytical and numerical modeling to provide a picture of the chiral mode hybridization responsible for this phenomenon. This work is an experimental realization of a magnonic diode and paves the way for designing complex spin-wave devices required for magnon computing.