Spin-Hall nanooscillator based on an antiferromagnetic domain wall

TL;DR

This paper introduces a high-frequency spin-Hall nano-oscillator utilizing an antiferromagnetic domain wall, capable of THz-range tunable oscillations with robust output, advancing spintronic device technology.

Contribution

It presents a novel design for a spin-Hall nano-oscillator based on antiferromagnetic domain walls, demonstrating tunability and robustness of the oscillations.

Findings

Auto-oscillation frequency tunable up to THz range.

Robust ac output achieved via conical precession of Néel vector.

Pinning of domain wall is essential for oscillator stability.

Abstract

We propose here a high-frequency spin-Hall nano-oscillator based on a simple magnetic texture, such as a domain wall, located in an antiferromagnet with easy-axis anisotropy type. We show that the spin current, polarized along the anisotropy axis, excites a conical precession of the N\'eel vector in such a domain wall, which allows obtaining a robust ac output signal, -- contrary to the planar precession in an uniform uniaxial antiferromagnet, where ac output is hard to achieve. The frequency of the auto-oscillations is easily tunable by the applied current up to the THz range, and the threshold current vanishes for pure uniaxial antiferromagnet. By micro-magnetic simulations, we demonstrate that the pinning of the domain wall is crucial for the oscillator design, which can be achieved in nano-constriction layout of the free layer.