Controlled interconversion of quantized spin wave modes via local magnetic fields

TL;DR

This paper demonstrates how local magnetic fields can selectively induce antisymmetric spin wave modes in magnonic waveguides, enabling controlled mode interconversion and interference pattern manipulation for advanced information processing.

Contribution

It introduces a method to controllably generate antisymmetric spin wave modes with even quantization numbers using local magnetic fields, expanding magnonic mode control capabilities.

Findings

Antisymmetric spin wave modes can be induced by local magnetic fields.

Interference patterns of spin waves are experimentally demonstrated.

An analytical model explains the observed phenomena.

Abstract

In the emerging field of magnonics, spin waves are considered for information processing and transmission at high frequencies. Towards this end, the manipulation of propagating spin waves in nanostructured waveguides for novel functionality has recently been attracting increasing focus of research. Excitations with uniform magnetic fields in such waveguides favors symmetric spin wave modes with odd quantization numbers. Interference between multiple odd spin wave modes leads to a periodic self-focusing effect of the propagating spin waves. Here we demonstrate, how antisymmetric spin wave modes with even quantization numbers can be induced by local magnetic fields in a well-controlled fashion. The resulting interference patterns are discussed within an analytical model and experimentally demonstrated using microfocused Brillouin light scattering ({\mu}-BLS).