High-frequency spin wave modes excited by strain pulse in vortex state magnetostrictive nanomagnets

Huanqing Cui,Yabo Chen,Jiahao Liu,Mingliang Zhang,Bo Wei,Jiahui Yuan,Lin Ni,Xiaokuo Yang

doi:10.1063/5.0070897

Abstract

Using micromagnetic simulations, we find that the high frequency spin wave modes of vortexes in circular magnetostrictive nanomagnets can be excited by in-plane strain pulses, which are quite distinct from the spin wave modes excited by magnetic field pulses. The spectrum and spatial distribution of spin wave modes are obtained as a function of the diameter (D) and thickness (L) of nanomagnets. Our results show that the increase in diameter leads to a redshift of the frequencies of spin wave modes. Furthermore, we investigate the impact of ring shape impurities on the high frequency spin wave modes, and it is found that both the type and position of impurities can be used to tailor the strain induced spin wave spectroscopy of magnetic vortexes. Our findings provide meaningful guidelines for the further study of strain-mediated sub-nanosecond magnetization dynamics, which may obviously improve the operating frequency of straintronic devices.

Highlights

Spin based nanomagnetic technology has attracted lots of attention for its intrinsic non-volatility,1 making it a promising candidate for the construction of logic-in-memory computing
We find that the high frequency spin wave modes of vortexes in circular magnetostrictive nanomagnets can be excited by in-plane strain pulses, which are quite distinct from the spin wave modes excited by magnetic field pulses
According to our previous study,12 the frequency of single domain nanomagnet based straintronic devices cannot exceed 1 GHz due to the magnetoelastic coupling induced 180○ magnetization switching mechanism, which cannot satisfy the demand of high-speed computing

Summary

INTRODUCTION

Spin based nanomagnetic technology has attracted lots of attention for its intrinsic non-volatility, making it a promising candidate for the construction of logic-in-memory computing. The method of controlling the magnetization is a key issue in spintronics. Traditional methods such as magnetic field induced magnetization switching or current-induced switching inevitably dissipate large amounts of energy, which may nullify the static power dissipation advantage of spin based logic devices. According to our previous study, the frequency of single domain nanomagnet based straintronic devices cannot exceed 1 GHz due to the magnetoelastic coupling induced 180○ magnetization switching mechanism, which cannot satisfy the demand of high-speed computing. We obtain the spectrum and spatial distribution of strain excited high-frequency spin wave modes of vortex state magnetostrictive nanomagnets as a function of geometry size. The impact of impurities on the strain excited spin wave spectroscopy of the magnetic vortex is investigated

MICROMAGNETIC MODEL

Strain excited high-frequency spin wave modes of magnetic vortex

The impact of impurities on the high-frequency spin wave modes

CONCLUSIONS