Spin-wave interference in three-dimensional rolled-up ferromagnetic microtubes

TL;DR

This study explores how spin waves behave in three-dimensional rolled-up ferromagnetic microtubes, revealing quantized modes influenced by the tube's geometry, which could impact future magnonic device design.

Contribution

It demonstrates the quantization of spin-wave modes in 3D microtubes and shows how their spectrum can be engineered by adjusting physical parameters.

Findings

Identification of quantized azimuthal spin-wave modes

Mode spectrum tunable by tube radius and layer number

Confirmation of spin-wave resonator behavior in microtubes

Abstract

We have investigated spin-wave excitations in rolled-up Permalloy microtubes using microwave absorption spectroscopy. We find a series of quantized azimuthal modes which arise from the constructive interference of Damon-Eshbach type spin waves propagating around the circumference of the microtubes, forming a spin-wave resonator. The mode spectrum can be tailored by the tube's radius and number of rolled-up layers.