Coherent elastic excitation of spin waves

We model the injection of elastic waves into a ferromagnetic film (F) by a nonmagnetic transducer (N). We compare the configurations in which the magnetization is normal and parallel to the wave propagation. The lack of axial symmetry in the former results in the emergence of evanescent interface states. We compute the energy-flux transmission across the N|F interface and sound-induced magnetization dynamics in the ferromagnet. We predict efficient acoustically induced pumping of spin current into a metal contact attached to F.