Magnonic Aharonov-Casher effect and electric field control of chirality-dependent spin-wave dynamics in antiferromagnets

Abstract

Effective control of spin-wave (SW) dynamics is among the current topical goals of research in magnonics. Electric field control of SW dynamics in insulating magnetic materials by creating the Aharonov-Casher (AC) topological phase without energy dissipation due to joule heating is a highly preferred way. The AC phase is purely a quantum phenomenon and has no classical interpretation. It manifests as the electric-field-induced shift in the SW's phase, group velocity direction, and SW's attenuation. Within a linear approximation, the magnonic AC effect can be considered by adding a Dzyaloshinskii-Moriya-like interaction between neighboring spins, which is proportional to the magnitude and sign of the applied electric field. We study the topological AC effect on magnetization dynamics in two-sublattice easy-axis insulating antiferromagnets. The analytical calculation indicates that a static electric field is an effective tool for selectively and successfully manipulating right-handed and left-handed polarized SWs, their amplitude, and propagation length. Our theory also reveals the electric field effect on anomalous magnon dispersion characteristics—a superluminal-like propagation of magnons at nanoscale distances. We also make numerical evaluations for antiferromagnetic dielectric to illustrate the theoretical predictions. The AC topological effect gives an effective method for the chirality-selective manipulation of magnon dynamics and opens promising research directions and practical applications of antiferromagnets in magnonics. Published by the American Physical Society 2025