Switchable long-distance propagation of chiral magnonic edge states

The coherent spin waves, magnons, can propagate without accompanying charge transports and Joule heat dissipation. Room-temperature and long-distance spin waves propagating within nanoscale spin channels are considered promising for integrated magnonic applications, but experimentally challenging. Here we report that long-distance propagation of chiral magnonic edge states can be achieved at room temperature in manganite thin films with long, antiferromagnetically coupled spin spirals (millimetre length) and low magnetic Gilbert damping (~3.04 × 10^-4). By directly observing the non-reciprocal spin-wave propagation and analysing the strong magnon-magnon coupling in the spiral textures, we elucidate the crucial role of the dynamic dipolar interaction on the birth and hybridization of this chiral magnonic edge state. The observed hybridized magnons with robust chirality can be reversibly and selectively switched on/off by different threshold angles under an external field, indicating great potential for the design of versatile magnonic devices at the nanoscale.