Excitation and coherent control of magnetization dynamics in magnetic tunnel junctions using acoustic pulses

Abstract

We experimentally study magnetization dynamics in magnetic tunnel junctions driven by femtosecond-laser-induced surface acoustic waves. The acoustic pulses induce a magnetization precession in the free layer of the magnetic tunnel junction through magnetoelastic coupling. The frequency and amplitude of the precession shows a pronounced dependence on the applied magnetic field and the laser excitation position. Comparing the acoustic-wave-induced precession frequencies with precession induced by charge currents and with micromagnetic simulations we identify spatially non-uniform magnetization modes localized close the edge regions as being responsible for the optically induced magnetization dynamics. The experimental scheme even allows us to coherently control the magnetization precession using two acoustic pulses. This might prove important for future applications requiring ultrafast spin manipulation. Additionally, our results directly pinpoint the importance of acoustic pulses since they could be relevant when investigating optically-induced temperature effects in magnetic structures.

arXiv comment17 pages, 4 figures

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Cited by in corpus (5)

• Straintronics: Manipulating the Magnetization of Magnetostrictive Nanomagnets with Strain for Energy-Efficient Applications
• Hybrid magneto-dynamical modes in a single magnetostrictive nanomagnet on a piezoelectric substrate arising from magneto-elastic modulation of precessional dynamics
• Controlling acoustic waves using magnetoelastic Fano resonances
• Full spatiotemporal control of laser-excited periodic surface deformations
• Surface Acoustic Wave induced modulation of tunneling magnetoresistance in magnetic tunnel junctions