Spin-Orbit Coupling-Driven Chirality Switching of Spin Waves in Altermagnets

TL;DR

This paper demonstrates a method to electrically switch the chirality of spin waves in altermagnets using Rashba spin-orbit coupling, enabling low-energy, fast, and controllable spintronic device functionalities.

Contribution

It introduces a novel mechanism for chirality switching in altermagnets via electrically induced SOC, avoiding external magnetic tuning.

Findings

Chirality of spin waves can be reversed by tuning SOC strength.

Chirality switching leads to reversal of transverse spin susceptibility.

Proposed experimental setup for practical realization.

Abstract

Altermagnets host intrinsically chirality-splitting spin waves, which offer an ideal platform for chirality-based computing with low energy consumption and fast dynamics. However, achieving precise and efficient control over spin-wave chirality remains a challenge. Here, we propose a mechanism to switch the chirality of spin waves in altermagnets via electrically induced Rashba spin-orbit coupling (SOC), which is free of tuning external fields. For in-plane spin polarization, SOC introduces a splitting effect opposite to the altermagnetism, leading to spin inversion in the electronic energy bands and chirality reversal in the spin-wave dispersion. By tuning SOC strength, the chirality splitting of spin waves can be controllably modified, enabling chirality switching at fixed resonance conditions, which results in the reversal of transverse spin susceptibility. We further design an experimental setup based on an altermagnet/antiferromagnet heterostructure to realize this mechanism. Our work establish a pathway toward efficient electrical control of spin-wave chirality in altermagnets, facilitating the development of chirality-based spintronic devices.