Goos-Hanchen Shift of a Spin-Wave Beam at the Interface Between Two Ferromagnets

TL;DR

This paper analytically investigates the Goos-Hanchen shift of spin waves at ferromagnetic interfaces, revealing how anisotropy influences phase control, with potential applications in magnonic metasurfaces for information processing.

Contribution

It provides an analytical model of spin wave reflection and refraction at ferromagnetic interfaces, highlighting the tunability of the Goos-Hanchen shift via interface anisotropy, which is a novel insight.

Findings

Goos-Hanchen shift can reach several wavelengths in reflection.

Interface anisotropy significantly affects the shift magnitude.

Subwavelength phase control of spin waves is achievable.

Abstract

Spin waves are promising information carriers which can be used in modern magnonic devices, characterized by higher performance and lower energy consumption than presently used electronic circuits. However, before practical application of spin waves, the efficient control over spin wave amplitude and phase needs to be developed. We analyze analytically reflection and refraction of the spin waves at the interface between two ferromagnetic materials. In the model we consider the system consisting of two semi-infinite ferromagnetic media, separated by the ultra-narrow interface region with the magnetic anisotropy. We have found the Goos-Hanchen shift for spin waves in transmission and reflection, and performed detailed investigations of its dependence on the anisotropy at the interface and materials surrounding the interface. We have demonstrated possibility of obtaining Goos-Hanchen shift of several wavelengths in reflection for realistic material parameters. That proves the possibility for change of the spin waves phase in ferromagnetic materials at subwavelength distances, which can be regarded as a metasurface for magnonics.