Multiple three-magnon splittings in bismuth yttrium iron garnet nanostructures

TL;DR

This paper experimentally demonstrates multiple three-magnon splitting processes in Bi-YIG nanostructures, revealing nonlinear spin-wave interactions with low power thresholds and tunable magnetic field conditions.

Contribution

It reports the first observation of multiple three-magnon splittings in Bi-YIG nanostructures using micro-focused Brillouin light scattering, highlighting nonlinear magnon dynamics.

Findings

Detection of three pairs of secondary modes around half the excitation frequency

Observation of threshold behavior and temporal dynamics of magnon interactions

Low power threshold enabled by BiYIG's properties

Abstract

We experimentally demonstrate the generation of multiple three-magnon splitting processes in an in-plane magnetized submicron Bi-YIG disk using micro-focused Brillouin light scattering. The low magnetic damping and strong magneto-optical response of BiYIG enable the detection of nonlinear spin-wave interactions at low threshold powers. By tuning the in-plane static magnetic field, excitation frequency, and power, we observe the generation of three pairs of secondary modes symmetrically distributed around half the excitation frequency. Time-resolved BLS measurements present temporal dynamics and threshold behavior associated with the successive activation of three-magnon pairs.