Direct Imaging of Resonant Phonon-Magnon Coupling

TL;DR

This paper demonstrates direct visualization of resonant magnon-phonon coupling in Ni/LiNbO3 heterostructures using micro focused Brillouin light scattering, revealing how magnetic fields modulate phonon interference patterns and enabling analysis of magnon properties.

Contribution

It introduces a method for directly imaging and analyzing resonant magnon-phonon interactions in hybrid structures using Brillouin light scattering.

Findings

Resonant magnon-phonon coupling visualized via Brillouin scattering.

Magnetic field modulates phonon interference patterns.

Magnon properties like resonance field and linewidth can be extracted.

Abstract

Direct detection of phonons is important for the investigation of information interconversion between the resonantly coupled magnons and phonons. Here we report resonant coupling of magnons and phonons, which can be directly visualized by using micro focused Brillouin light scattering in Ni/LiNbO3 hybrid heterostructures. The patterns of surface acoustic wave phonons, originating from the interference between the original wave {\psi}0(A_0,k) and reflected wave {\psi}1(A_1,-k), can be modulated by magnetic field due to the magnon-phonon coupling. By analyzing the information of phonons obtained from Brillouin spectroscopy, the properties of the magnon system (Ni film), e.g., ferromagnetic resonance field and resonance linewidth can be determined. The results provide spatially resolved information about phonon manipulation and detection in a coupled magnon-phonon system.