2021/11/02 by D. Turenne, Diego Turenne, A. Yaroslavtsev +107
Engineering · Materials Science · Physics and Astronomy · #FOS: Physical sciences #Magnetic Properties and Applications #Magnetic properties of thin films #Magneto-Optical Properties and Applications #Materials Science (cond-mat.mtrl-sci) #cond-mat.mtrl-sci
paper · pdf · doi:10.48550/arxiv.2111.01649
32 pages, please check the "attachemnts" tab in the pdf file in order to see the movie
arxiv created 2021/11/02 · openalex publication_date 2021/11/02 · arxiv updated 2021/11/03 · openalex created_date 2021/11/08 · openalex updated_date 2026/07/28
Magnetic nanoparticles such as FePt in the L10-phase are the bedrock of our current data storage technology. As the grains become smaller to keep up with technological demands, the superparamagnetic limit calls for materials with higher magneto-crystalline anisotropy. This in turn reduces the magnetic exchange length to just a few nanometers enabling magnetic structures to be induced within the nanoparticles. Here we describe the existence of spin-wave solitons, dynamic localized bound states of spin-wave excitations, in FePt nanoparticles. We show with time-resolved X-ray diffraction and micromagnetic modeling that spin-wave solitons of sub-10 nm sizes form out of the demagnetized state following femtosecond laser excitation. The measured soliton spin-precession frequency of 0.1 THz positions this system as a platform to develop miniature devices capable of filling the THz gap.