Alignment-Dependent Gapless Chiral Split Magnons in Altermagnetic Domain Walls

TL;DR

This paper reports the discovery of gapless chiral split magnons confined within altermagnetic domain walls, which are sensitive to domain wall orientation, detectable in the microwave regime, and controllable via spin-orbit torque, opening new avenues for magnonic devices.

Contribution

It introduces the existence of gapless chiral split magnons in altermagnetic domain walls and demonstrates their controllability and potential for magnonic applications, a novel finding in the field.

Findings

Magnons are confined within altermagnetic domain walls.

Magnon spectrum depends on domain wall orientation.

Spin-orbit torque can manipulate magnon behavior.

Abstract

Altermagnets, an emerging class of magnetic materials, exhibit exotic chiral split magnons that are of great interest for both fundamental physics and spintronic applications. However, detecting and manipulating these magnons is challenging due to their THz frequency response. Here, we report the discovery of gapless chiral split magnons confined within altermagnetic domain walls. Unlike in conventional ferromagnets or antiferromagnets, their spectrum is highly sensitive to the domain wall orientation relative to the crystal axis. These magnons inherit the chiral splitting of their bulk counterparts and are detectable in the microwave regime, offering a distinctive signature for identifying altermagnets. We further show that the interfacial Dzyaloshinskii-Moriya interaction drives hybridization of magnons with opposite chiralities, enabling unidirectional strong magnon-magnon coupling. Moreover, we demonstrate that spin-orbit torque can control the domain wall orientation, providing a practical means to manipulate these chiral magnons. Our findings open pathways for novel magnonic nanocircuitry based on altermagnetic domain walls.