Magnetochiral Properties of Spin Waves Existing in Nanotubes with Axial and Circumferential Magnetization

TL;DR

This study experimentally investigates spin-wave excitations in NiFe nanotubes, revealing non-reciprocal modes and magnetochiral effects that advance understanding of 3D nanomagnonics.

Contribution

It provides the first experimental observation of magnetochiral spin-wave modes in nanotubes with detailed mode characterization.

Findings

Identification of discrete spin-wave resonances in nanotubes.

Observation of non-reciprocal, helical phase modes.

Insight into magnetochiral effects in 3D nanostructures.

Abstract

We report experimental studies of spin-wave excitations in individual 22 nm thick Ni80Fe20 nanotubes with diameters of about 150 nm by means of Brillouin light-scattering (BLS) spectroscopy. Irradiated by microwaves we resolve sets of discrete resonances in the center of nanotubes ranging from 2.5 to 12.5 GHz. Comparing to a recent theoretical work and micromagnetic simulations, we identify different characteristic eigenmodes depending on the axial, mixed or vortex configuration. The mixed and vortex states give rise to modes with helical phase profiles substantiating an unusual nature of modes attributed to non-reciprocal spin waves. Our findings provide microscopic insight into tubular spin-wave nanocavities and magnetochiral effects for 3D nanomagnonics.