Coherent oscillation between phonons and magnons

Two different waves with the same frequency and wavelengths can be coupled, so that the amplitude alternates periodically between the two to form a phenomenon known as a coherent beating oscillation. The process can be observed often with a coupled pendulum, and at the cosmic scale as neutrino oscillations that occur due to fluctuations between diverse neutrinos. Solids too can equally maintain various wave excitations to contribute to their thermal and electromagnetic properties.