Photodrive of magnetic bubbles via magnetoelastic waves

Significance In contemporary spintronics, spin transfer torque exerted by a spin-polarized current is often used to control magnetic domains. In addition to it, magnons in both metals and insulators are now regarded as an attractive alternative to deliver and exchange spin momentum with magnetic domain walls. We demonstrate that (i ) magnetoelastic waves (coupled propagation of phonon and magnon) can be generated in an iron garnet film by ultrafast laser pulses, to be a versatile source of spin momentum, and (ii ) this traveling spin excitation drives the magnetic domains; more efficiently for those with steeper curvatures at the wall. The latter, the emergent electromagnetic response of the curved domain wall, can be understood by expanding the Thiele equation.