2008/01/30 by Markus Bolte, Guido Meier, Benjamin Krüger +13 · 2 citations
Engineering · Physics and Astronomy · #Characterization and Applications of Magnetic Nanoparticles #Magnetic properties of thin films #Physics of Superconductivity and Magnetism #cond-mat.mtrl-sci #cond-mat.other
paper · pdf · doi:10.1103/physrevlett.100.176601
10 pages, 3 figures
arxiv created 2008/01/30 · openalex publication_date 2008/04/30 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Time-resolved x-ray microscopy is used to image the influence of alternating high-density currents on the magnetization dynamics of ferromagnetic vortices. Spin-torque-induced vortex gyration is observed in micrometer-sized permalloy squares. The phases of the gyration in structures with different chirality are compared to an analytical model and micromagnetic simulations, considering both alternating spin-polarized currents and the current's Oersted field. In our case the driving force due to spin-transfer torque is about 70% of the total excitation while the remainder originates from the current's Oersted field. This finding has implications to magnetic storage devices using spin-torque driven magnetization switching and domain-wall motion.