Deterministic Ultra‐Fast All‐Optical Switching in Gd free Ferrimagnetic Spin Valve Structures

作者：Wei Zhang, M. Hehn, Peng Yi, Jon Gorchon, Quentin Remy, Jun‐Xiao Lin, J. Hohlfeld, G. Malinowski, Wei Zhao, S. Mangin · 发表于：Advanced Functional Materials · 年份：2025 · DOI：10.1002/adfm.202505423 · 被引用次数：2 · 研究领域：Magnetic properties of thin films、Magneto-Optical Properties and Applications、Characterization and Applications of Magnetic Nanoparticles

Abstract All‐optical magnetization switching (AOS) using single femtosecond laser pulses has emerged as a promising path for future ultrafast and energy‐efficient spintronic devices, as it enables magnetization reversal on the picosecond timescale. However, most ultrafast phenomena demonstrated so far have only resulted in magnetization toggling, requiring prior knowledge of the initial state to write a bit. Deterministic ultrafast magnetization switching has been largely restricted to Gd‐based multilayers and necessitates the application of two successive laser pulses. In this work, a Gd‐free ferrimagnetic (TbCo or DyCo)/Cu/ferromagnetic (Co/Pt) spin‐valve structure is designed and single‐pulse‐induced ultra‐fast magnetization switching in high‐anisotropy materials is experimentally demonstrated using TbCo and DyCo alloys. Interestingly, for a specific pulse duration (resp. for a given laser fluence), the final magnetic state after a single femtosecond laser pulse depends solely on the laser fluence (resp. pulse duration) and is entirely independent of the initial state. This enables deterministic writing and erasing of magnetization by simply varying one laser parameter. These effects are summarized in a state diagram that maps the results of single laser pulses as functions of both pulse duration and fluence. This breakthrough paves the way for the realization of future optical ultrafast spintronic memory devices.