Modification of the thermal spin-wave spectrum in a Ni81Fe19 stripe by a domain wall

TL;DR

This study investigates how an asymmetric transverse domain wall in a Ni81Fe19 stripe affects the thermal spin-wave spectrum, revealing mode suppression and evolution due to internal field changes, supported by experiments and simulations.

Contribution

It demonstrates the influence of domain walls on thermal spin-wave modes and provides experimental and simulation evidence of these effects in a Ni81Fe19 stripe.

Findings

Thermal spin-wave modes are quantized and vanish near the domain wall.

A new spin-wave mode emerges within the domain wall region.

Experimental results align with micromagnetic simulations.

Abstract

The thermal spin-wave distribution in a Ni81Fe19 stripe with an asymmetric transverse domain wall has been investigated using Brillouin light scattering microscopy. Clear evidence has been found that the existence of the domain wall influences the spin-wave distribution of the thermal modes. The thermal spin-wave modes are quantized due to the confinement in radial direction. They vanish near the domain wall and a new mode evolves inside this complex domain wall structure. This effect is attributed to a change of the effective internal field in the domain wall region. The experimental results agree well with static and dynamic micromagnetic simulations.