Controlling effective field contributions to laser-induced magnetization precession by heterostructure design

• DOI: 10.1038/s42005-024-01602-z
• Publication Date: 2024-03-30T13:01:49Z
• Authors: Jasmin Jarecki; Maximilian Mattern; Fried-Conrad Weber; Jan-Etienne Pudell; Xi-Guang Wang; Juan-Carlos Rojas...; Michel Hehn; Alexander von Rep...; Matias Bargheer
• Keywords: Condensed Matter - Materials Science; temperature variation ; optical excitation; Physics; QC1-999; ddc:530; Institut für Physik und Astronomie; Materials Science (cond-mat.mtrl-sci); FOS: Physical sciences; 02 engineering and technology; Astrophysics; QB460-466; 0210 nano-technology

AbstractNanoscale heterostructure design can control laser-induced heat dissipation and strain propagation, as well as their efficiency for driving magnetization precession. Here, we incorporate MgO layers into the experimental platform of metallic Pt-Cu-Ni heterostructures to block the propagation of hot electrons. We show via ultrafast x-ray diffraction the capability of our platform to control the spatio-temporal shape of the transient heat and strain. Time-resolved magneto-optical Kerr experiments with systematic tuning of the magnetization precession frequency showcase control of the magnetization dynamics in the Ni layer. Our experimental analysis highlights the role of quasi-static strain as a driver of precession when the magnetic material is rapidly heated via electrons. The effective magnetic field change originating from demagnetization partially compensates the change induced by quasi-static strain. The strain pulses can be shaped via the nanoscale heterostructure design to efficiently drive the precession, paving the way for opto-magneto-acoustic devices with low heat energy deposited in the magnetic layer.