Effect of inhomogeneous Dzyaloshinskii-Moriya interaction on antiferromagnetic spin-wave propagation

TL;DR

This paper explores how inhomogeneous Dzyaloshinskii-Moriya interaction affects antiferromagnetic spin-wave propagation, revealing amplification, band structure control, and polarization-dependent phase shifts, with potential applications in magnonic devices.

Contribution

It introduces a theoretical and numerical analysis of inhomogeneous DMI effects on antiferromagnetic spin waves, including amplification and polarization control mechanisms.

Findings

Antiferromagnetic spin waves can be amplified at DMI boundaries.

Inhomogeneous DMI creates magnonic band gaps in terahertz frequencies.

Spin waves experience polarization-dependent phase shifts passing through inhomogeneous DMI.

Abstract

We investigate the effect of inhomogeneous Dzyaloshinskii-Moriya interaction (DMI) on antiferromagnetic spin-wave propagation theoretically and numerically. We find that antiferromagnetic spin waves can be amplified at a boundary where the DMI varies. The inhomogeneous DMI also provides a way to construct a magnonic crystal with forbidden and allowed antiferromagnetic spin-wave bands in terahertz frequency ranges. In contrast to ferromagnetic spin waves, antiferromagnetic spin waves experience a polarization-dependent phase shift when passing through the inhomogeneous DMI, offering a magnonic crystal that also serves as a spin-wave polarizer.