Efficient motion of 90^{\circ} domain walls in Mn_{2}Au via pure optical torques

TL;DR

This study demonstrates that optical torques can efficiently move 90-degree domain walls in Mn2Au antiferromagnets, revealing relativistic effects and texture nucleation at high velocities, advancing all-optical spintronics.

Contribution

It introduces a novel method of driving 90-degree domain walls using optical torques in Mn2Au, highlighting symmetry constraints and relativistic dynamics.

Findings

Optical torques effectively drive 90-degree domain walls.

180-degree walls are forbidden to move due to symmetry.

High-velocity regime involves nucleation of magnetic textures.

Abstract

Discovering alternative ways to drive domain wall (DW) dynamics is crucial for advancing spintronic applications. Here we demonstrate via atomistic spin dynamics simulations that optical torques can efficiently drive 90^{\circ} DWs in the Mn2Au antiferromagnet but their spatial symmetry forbids the motion of 180^{\circ} walls. In the steady-state regime, the kinematics display special relativity signatures accessed for low laser intensities. At velocities higher than the magnonic limit, the DW enters a proliferation regime in which part of its relativistic energy is invested into the nucleation of novel magnetic textures. Our investigation contributes towards the fundamental understanding of opto-magnetic effects, supporting the development of next generation, all-optically controlled antiferromagnetic spintronics.