Optical probing of magnons and phonons in Ni80Fe20 nanodot arrays

Abstract

Control of collective spin excitations by static or dynamic strain is an emerging phenomenon that requires in-depth understanding for the design of future spin-wave-regulated devices. Here, we explore mutually interacting spin waves and acoustic wave modes in addition to a few non-interactive modes through all optical excitation in ordered arrays of Ni₈₀Fe₂₀ nanomagnets. The acoustic wave originating from elastic deformation resonantly couples to the spin wave via the magnetoelastic effect at their overlapping frequency. We demonstrate that the choice of the lattice type in which the magnetic nanodots are arranged is crucial for the observation of the magnetoelastic interaction. Therefore, this study shows that the simultaneous existence of elastic wave and spin wave offer ingeniously advantageous features to pave the way towards energy-efficient magnetoacoustic devices.