Actuation, propagation, and detection of transverse magnetoelastic waves in ferromagnets

We study propagation of ultrasonic waves through a ferromagnetic medium with special attention to the boundary conditions at the interface with an ultrasonic actuator. In analogy to charge and spin transport in conductors, we formulate the energy transport through the system as a scattering problem. We find that the magneto-elastic coupling leads to a non-vanishing magnetic (elastic) energy accompanying the acoustic (spin) waves with a resonantly enhanced effect around the dispersion relation anti-crossing point. We demonstrate the physics of excitation of magnetization dynamics via acoustic waves injection around the ferromagnetic resonance frequency.