Dresden 2020 – wissenschaftliches Programm
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MA 15.3: Vortrag
Montag, 16. März 2020, 15:30–15:45, HSZ 403
Optimal control of magnetization switching in nanowires — •Mohammad Badarneh1, Grzegorz Kwiatkowski1, and Pavel Bessarab1,2,3 — 1University of Iceland, Reykjavík, Iceland — 2ITMO University, St. Petersburg, Russia — 3Peter Grünberg Institute and Institute for Advanced Simulation, Forschungszentrum Jülich, Jülich, Germany
We explore theoretical limits for the energy-efficient control of switching phenomena in bistable magnetic nanowires. We calculate optimal control paths (OCPs) for the magnetization switching as functions of the switching time, damping and various parameters of the nanowires. Following an OCP involves concerted rotation of the magnetic moments in such a way that the system’s internal modes are effectively used to aid magnetization switching. OCP calculations demonstrate that short nanowires reverse their magnetization via coherent rotation which can be induced by applying uniform external magnetic field with frequency defined by a collective in-phase precession of the magnetization. If the length of the wire exceeds a certain critical length, standing spin wave emerges during magnetization switching. Such spin wave assisted magnetization switching has recently attracted much attention as a promising technique to reduce the switching field for magnetic recording. Our results demonstrate that optimal switching mechanisms and corresponding control stimuli can be predicted from first principles, contributing to the development of low-power technologies.
This work was funded by the Russian Science Foundation (Grant No. 19-72-10138) and the Icelandic Reseach Fund (Grant No. 184949-052).