Spin-wave Goos-H\"{a}nchen effect induced by 360 degree domain walls in magnetic heterostructures

TL;DR

This paper investigates the lateral displacements of spin waves at 360-degree domain walls in magnetic heterostructures, revealing a novel spin-wave Goos-H"{a}nchen effect influenced by interfacial interactions and anisotropy.

Contribution

It demonstrates the existence of the spin-wave Goos-H"{a}nchen effect at 360-degree domain walls, even without interfacial Dzyaloshinskii-Moriya interactions, due to unique potential profiles.

Findings

Lateral displacements are fractions of the spin-wave wavelength.

Displacements can be enhanced with arrays of 360DWs.

SWGHE persists in biaxial anisotropy ferromagnets without IDMI.

Abstract

In this work, lateral displacements of transmitted and reflected spin waves at a 360 degree domain wall (360DW), which is referred to as the spin-wave Goos-H\"{a}nchen effect (SWGHE), are systematically investigated in magnetic heterostructures with perpendicular easy/hard axis and wall-extension direction. Similar to the counterpart at heterochiral interfaces, the interfacial Dzyaloshinskii-Moriya interactions (IDMI) originating from a heavy-metal substrate is important for the emergence of SWGHE. More interestingly, the SWGHE can even survive in ferromagnets with biaxial anisotropy (either intrinsic or caused by shape anisotropy) in the absence of IDMI due to the unique 360DW-induced potentials which are distinct to the well-known P\"{o}schl-Teller ones. Numerics shows that these lateral displacements are generally fractions of the spin-wave wavelength. They can be further enhanced by an array of well-separated 360DWs thus provide a large variety for spin-wave manipulation.