Formation of Bright Solitons from Wave Packets with Repulsive Nonlinearity

TL;DR

This paper reports the first experimental observation of bright envelope solitons forming from wave packets with repulsive nonlinearity in magnetic YIG thin films, supported by numerical simulations.

Contribution

It demonstrates the formation of bright solitons from repulsive nonlinearity, a phenomenon not previously observed experimentally, using surface spin-wave packets.

Findings

Bright solitons form from wave packets with high power or wide width.

Low-power, narrow wave packets undergo self-broadening.

Numerical simulations confirm experimental observations.

Abstract

Formation of bright envelope solitons from wave packets with a repulsive nonlinearity was observed for the first time. The experiments used surface spin-wave packets in magnetic yttrium iron garnet (YIG) thin film strips. When the wave packets are narrow and have low power, they undergo self-broadening during the propagation. When the wave packets are relatively wide or their power is relatively high, they can experience self-narrowing or even evolve into bright solitons. The experimental results were reproduced by numerical simulations based on a modified nonlinear Schr\"odinger equation model.