Observation of Antiferromagnetic Magnon Pseudospin Dynamics and the Hanle effect

TL;DR

This paper demonstrates the coherent control of magnon pseudospin dynamics in antiferromagnetic hematite, revealing an analog of the Hanle effect and paving the way for advanced antiferromagnetic magnonic devices.

Contribution

It provides the first experimental observation of magnon pseudospin precession and the Hanle effect in an antiferromagnetic insulator using all-electrical methods.

Findings

Magnon spin signals oscillate with magnetic field polarity.

Coherent pseudospin precession explained by anisotropy and Dzyaloshinskii-Moriya interaction.

Potential for antiferromagnetic magnonic electronics.

Abstract

We report on experiments demonstrating coherent control of magnon spin transport and pseudospin dynamics in a thin film of the antiferromagnetic insulator hematite utilizing two Pt strips for all-electrical magnon injection and detection. The measured magnon spin signal at the detector reveals an oscillation of its polarity as a function of the externally applied magnetic field. We quantitatively explain our experiments in terms of diffusive magnon transport and a coherent precession of the magnon pseudospin caused by the easy-plane anisotropy and the Dzyaloshinskii-Moriya interaction. This experimental observation can be viewed as the magnonic analogue of the electronic Hanle effect and the Datta-Das transistor, unlocking the high potential of antiferromagnetic magnonics towards the realization of rich electronics-inspired phenomena.