Phys. Rev. B 104, L180401 (2021)

Magnetically switchable spin-wave retarder with 90^∘ antiferromagnetic domain wall

Feiyang Ye and Jin Lan*

Center for Joint Quantum Studies and Department of Physics, School of Science, Tianjin University, 92 Weijin Road, Tianjin 300072, China

* Corresponding author :   lanjin@tju.edu.cn

Abstract

Polarization, denoting the precession direction with respect to the background magnetization, is an intrinsic degree of freedom of a 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^∘ antiferromagnetic domain wall naturally acts as a spin-wave retarder (waveplate). Moreover, for a 90^∘ domain wall pair developed by introducing a second domain in a homogenous antiferromagnetic wire, the sign of the retarding effect can be flipped by simply switching the magnetization direction of the intermediate domain.