# Antiferromagnetic textures and dynamics on the surface of a heavy metal

## TL;DR

This paper explores how antiferromagnetic textures form and behave on heavy metal surfaces, revealing ultrafast dynamics driven by spin currents and proposing new experimental approaches for Terahertz spin-torque oscillators.

## Contribution

It demonstrates the formation of nontrivial antiferromagnetic textures and ultrafast dynamics induced by spin currents, and introduces a new geometry for experimental realization.

## Key findings

- Ultrafast (THz) oscillations of Néel order driven by current
- Effective anisotropy and Dzyaloshinskii-Moriya interactions influence textures
- Proposed alternative geometry for ultrafast antiferromagnetic dynamics

## Abstract

We investigate the formation and dynamics of spin textures in antiferromagnetic insulators adjacent to a heavy-metal substrate with strong spin-orbit interactions. Exchange coupling to conduction electrons engenders an effective anisotropy, Dzyaloshinskii-Moriya interactions, and a magnetoelectric effect for the N\'{e}el order, which can conspire to produce nontrivial antiferromagnetic textures. Current-driven spin transfer enabled by the heavy metal, furthermore, triggers ultrafast (THz) oscillations of the N\'{e}el order for dc currents exceeding a critical threshold, opening up the possibility of Terahertz spin-torque self-oscillators. For a commonly invoked antidamping-torque geometry, however, the instability current scales with the energy gap of the antiferromagnetic insulator and, therefore, may be challenging to reach experimentally. We propose an alternative generic geometry for inducing ultrafast autonomous antiferromagnetic dynamics.