Modelling spin waves in noncollinear antiferromagnets: spin-flop states, spin spirals, skyrmions and antiskyrmions

Abstract

Spin waves in antiferromagnetic materials have great potential for next-generation magnonic technologies. However, their properties and their dependence on the type of ground-state antiferromagnetic structure are still open questions. Here, we investigate theoretically spin waves in one- and two-dimensional model systems with a focus on noncollinear antiferromagnetic textures such as spin spirals and skyrmions of opposite topological charges. We address in particular the nonreciprocal spin excitations recently measured in bulk antiferromagnet $\alpha$--${\text{Cu}}_2{\text{V}}_2{\text{O}}_7$ utilizing inelastic neutron scattering experiments [Phys.\ Rev.\ Lett.\ \textbf{119}, 047201 (2017)], where we help to characterize the nature of the detected spin-wave modes. Furthermore, we discuss how the Dzyaloshinskii-Moriya interaction can lift the degeneracy of the spin-wave modes in antiferromagnets, resembling the electronic Rashba splitting. We consider the spin-wave excitations in antiferromagnetic spin-spiral and skyrmion systems and discuss the features of their inelastic scattering spectra. We demonstrate that antiskyrmions can be obtained with an isotropic Dzyaloshinskii-Moriya interaction in certain antiferromagnets.

26 pages, 9 figures

References in corpus (10)

• Advances in the Physics of Magnetic Skyrmions and Perspective for Technology
• Spontaneous Skyrmion Ground States in Magnetic Metals
• Magnetic skyrmion logic gates: conversion, duplication and merging of skyrmions
• Spirit: Multifunctional Framework for Atomistic Spin Simulations
• Antiferromagnetic skyrmion crystals: generation, topological Hall and topological spin Hall effect
• Topological Magnons and Edge States in Antiferromagnetic Skyrmion Crystals
• Spin excitations in a single La${}_2$CuO${}_4$ layer
• Spin Orbit Coupling and Spin Waves in Ultrathin Ferromagnets: The Spin Wave Rashba Effect
• Spin eigen-excitations of an antiferromagnetic skyrmion
• Magnetic Phase Control in Monolayer Films by Substrate Tuning

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• Nonreciprocal spin-wave dynamics in Pt/Co/W/Co/Pt multilayers
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• Complex magnetism of the two-dimensional antiferromagnetic Ge2F: from a Néel spin-texture to a potential antiferromagnetic skyrmion