Magnetically switchable spin wave retarder with $90^\circ$ antiferromagnetic domain wall

TL;DR

This paper demonstrates that a 90-degree antiferromagnetic domain wall can act as a spin wave retarder, with the ability to switch the retarding effect by manipulating the domain configuration, advancing reprogrammable magnonic devices.

Contribution

It introduces the concept of using intrinsic cubic anisotropy in antiferromagnetic textures to control spin wave polarization in a reprogrammable manner.

Findings

A 90-degree antiferromagnetic domain wall functions as a spin wave retarder.

The retarding effect can be flipped by switching the intermediate domain.

The mechanism relies on intrinsic cubic anisotropy and domain wall configurations.

Abstract

Polarization, denoting the precession direction with respect to the background magnetization, is an intrinsic degree of freedom of spin wave. Using magnetic textures to control the spin wave polarization is fundamental and indispensable toward reprogrammable polarization-based magnonics. Here, we show that due to the intrinsic cubic anisotropy, a $90^\circ$ antiferromagnetic domain wall naturally acts as a spin wave retarder (wave-plate). Moreover, for a $90^\circ$ domain wall pair developed by introducing a second domain in a homogenous antiferromagnetic wire, the sign of retarding effect can be flipped by simply switching the direction of the intermediate domain.