Chirality and polarization of inertial antiferromagnetic resonances driven by spin-orbit torques

TL;DR

This paper demonstrates that the polarization and handedness of inertial antiferromagnetic resonant modes can be actively controlled by tailoring spin-orbit torque polarization, allowing continuous evolution of mode polarization unlike in ferromagnets.

Contribution

It introduces a method to control the polarization and handedness of AFM inertial modes through tailored spin-orbit torques, revealing new dynamic behaviors.

Findings

AFM inertial modes can be continuously tuned from elliptic to linear polarization.

A critical polarization degree causes mode linearization and handedness reversal.

Active control of AFM mode polarization is achievable via spin-orbit torque polarization.

Abstract

It is widely accepted that the handedness of a resonant mode is an intrinsic property. We show that, by tailoring the polarization and handedness of alternating spin-orbit torques used as the driving force, the polarization state and handedness of inertial resonant modes in an antiferromagnet (AFM) can be actively controlled. In contrast with ferromagnets, whose resonant-mode polarization is essentially fixed, AFM inertial modes can continuously evolve from elliptic through circular to linear polarization as the driving polarization is varied. We further identify an inertia-dependent critical degree of driving polarization at which the mode becomes linearly polarized while its handedness reverses.