Total Reflection and Negative Refraction of Dipole-Exchange Spin Waves at Magnetic Interfaces: Micromagnetic Modeling Study

TL;DR

This study demonstrates that dipole-exchange spin waves in magnetic thin films exhibit reflection, refraction, total reflection, and negative refraction behaviors similar to light waves, revealing new wave phenomena at magnetic interfaces.

Contribution

First demonstration of total reflection and negative refraction of dipole-exchange spin waves at magnetic interfaces using micromagnetic modeling.

Findings

Dipole-exchange spin waves obey reflection and refraction laws.

Total reflection occurs at inhomogeneous magnetic interfaces.

Negative refraction is observed at domain-wall magnetic interfaces.

Abstract

We demonstrated that dipole-exchange spin waves traveling in geometrically restricted magnetic thin films satisfy the same laws of reflection and refraction as light waves. Moreover, we found for the first time novel wave behaviors of dipole-exchange spin waves such as total reflection and negative refraction. The total reflection in laterally inhomogeneous thin films composed of two different magnetic materials is associated with the forbidden modes of refracted dipole-exchange spin waves. The negative refraction occurs at a 90 degree domain-wall magnetic interface that is introduced by a cubic magnetic anisotropy in the media, through the anisotropic dispersion of dipole-exchange spin waves.