Spin-Hall nano-oscillator with oblique magnetization and Dzyaloshinskii-Moriya interaction as generator of skyrmions and nonreciprocal spin-waves

TL;DR

This study demonstrates that Spin-Hall oscillators with oblique magnetization and Dzyaloshinskii-Moriya interaction can generate nonreciprocal spin-waves and skyrmions, offering new functionalities for magnonic devices and ultralow power computing.

Contribution

It provides an analytical and micromagnetic analysis of magnetization dynamics in Spin-Hall oscillators, revealing their ability to generate skyrmions and nonreciprocal spin-waves.

Findings

Nonreciprocal spin-waves propagating perpendicularly to magnetization

Generation of skyrmions by pure spin-current

Discovery of a spiral spin-wave mode from skyrmion gyrotropic rotation

Abstract

Spin-Hall oscillators are promising sources of spin-wave signals for magnonics applications, and can serve as building blocks for magnonic logic in ultralow power computation devices. Here, we analytically and micromagnetically study magnetization dynamics excited in a Spin-Hall oscillator with oblique magnetization when the spin-Hall effect and interfacial Dzyaloshinskii-Moriya interaction act simultaneously. Our key results are (i) excitation of nonreciprocal spin-waves propagating perpendicularly to the in-plane projection of the static magnetization, (ii) skyrmions generation by pure spin-current, (iii) excitation of a new spin-wave mode with a spiral spatial profile originating from a gyrotropic rotation of a dynamical skyrmion. These results demonstrate that Spin-Hall oscillators can be used as generators of magnetic skyrmions and different types of propagating spin-waves for magnetic data storage and signal processing applications.