Magnonic Goos-Hanchen effect induced by one dimensional solitons

TL;DR

This paper demonstrates a magnonic Goos-Hanchen effect caused by one-dimensional solitons in monoaxial helimagnets, showing how spin waves experience lateral shifts upon scattering, with potential for tunable magnonic applications.

Contribution

It introduces a novel Goos-Hanchen effect at soliton positions in magnetic systems, extending the phenomenon beyond interfaces to include solitons and domain walls.

Findings

Spin waves are laterally displaced when scattered by solitons.

The displacement can be significantly enhanced using arrays of solitons.

The effect is generic to various magnetic states, including domain walls.

Abstract

The magnon spectral problem is solved in terms of the spectrum of a diagonalizable operator for a generic class of magnetic states that includes several types of domain walls and the chiral solitons of monoaxial helimagnets. Focusing on the isolated solitons of monoaxial helimagnets, it is shown that the spin waves scattered (reflected and transmitted) by the soliton suffer a lateral displacement analogous to the Goos-Hanchen effect of optics. The displacement is a fraction of the wavelength, but can be greatly enhanced by using an array of well separated solitons. Contrarily to the Goos-Hanchen effect recently studied in some magnetic systems, which takes place at interfaces between different magnetic systems, the effect predicted here takes place at the soliton position, what it is interesting from the point of view of applications since solitons can be created at different places and moved across the material. This kind of Goos-Hanchen effect is not particular of monoaxial helimagnets, but it is generic of a class of magnetic states, including domain walls in systems with interfacial Dzyaloshinskii-Moriya interaction.