Resonant magneto-acoustic switching: influence of Rayleigh wave frequency and wavevector

P Kuszewski,L Becerra,W Savero Torres,J-Y Duquesne,N Biarrotte,C Gourdon,J Von Bardeleben,A Lemaître,I S Camara,L Thevenard

doi:10.1088/1361-648x/aac152

Abstract

We show on in-plane magnetized thin films that magnetization can be switched efficiently by 180 degrees using large amplitude Rayleigh waves travelling along the hard or easy magnetic axis. Large characteristic filament-like domains are formed in the latter case. Micromagnetic simulations clearly confirm that this multi-domain configuration is compatible with a resonant precessional mechanism. The reversed domains are in both geometries several hundreds of , much larger than has been shown using spin transfer torque- or field-driven precessional switching. We show that surface acoustic waves can travel at least 1 mm before addressing a given area, and can interfere to create magnetic stripes that can be positioned with a sub-micronic precision.

Highlights

Resonant magnetization switching relies on triggering large angle magnetization precession by high frequency stimuli
Sub nanosecond deterministic switching was demonstrated using short magnetic field pulses [1,2,3,4,5,6,7], spin transfer torque (STT) [8,9,10,11,12,13], electric fields or ultra-short light pulses [14,15,16] to induce an efficient torque on the magnetization
We have presented a comprehensive investigation of resonant magnetic switching by a surface acoustic wave with a special emphasis on the role of the surface acoustic waves [17–19] (SAWs) frequency and the interplay between the SAW wavevector direction and the easy magnetic axis

Summary

Introduction

Resonant magnetization switching relies on triggering large angle magnetization precession by high frequency stimuli. Voltage-driven ‘straintronics’ hold the promise of a lower power consumption [14, 15, 24]. In this framework, we report on the optimum conditions for acoustic magnetization reversal, and hint to its limits. Micromagnetic simulations validate the resonant switching mechanism at work, and the shape of the domains. Acoustic attenuation variations calculated for a SAW propagating along [1 ̄1 0] at f0, 3f0, 5f0 and 7f0—same color coding as (a). (c) SAW attenuation variations at resonance, extracted from the data of (a) and the calculation of (b) Acoustic attenuation variations calculated for a SAW propagating along [1 ̄1 0] at f0, 3f0, 5f0 and 7f0—same color coding as (a). (c) SAW attenuation variations at resonance, extracted from the data of (a) and the calculation of (b)

Experimental methods

Conclusion