Curvilinear manipulation of polarized spin waves

Abstract

Polarization, the precession direction with respect to the background magnetization, is an intrinsic degree of freedom of spin wave. Introducing symmetry-breaking mechanisms lies in the heart of lifting the degeneracy between polarized spin-wave modes and is essential in constructing polarization-based magnonic devices. Here we show that polarized spin waves can be naturally harnessed in a curved antiferromagnetic wire via tuning its curvature and torsion. Specifically, we investigate evolution of polarized spin wave in a spin-wave rotator and a spin-wave interferometer based on magnetic circular helices and correlate these curvilinear effects to the Berry phase accumulated along the wire.