Regensburg 2019 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 11: Focus Session: Magnetic materials for energy efficient applications
MA 11.6: Vortrag
Montag, 1. April 2019, 18:15–18:30, H38
Design of control field pulses to efficiently induce magnetic transitions — •Pavel F. Bessarab1,2 and Grzegorz Kwiatkowski1,3 — 1University of Iceland, Reykjavík, Iceland — 2ITMO University, St. Petersburg, Russia — 3Immanuel Kant Baltic Federal Uni- versity, Kaliningrad, Russia
Control of magnetization switching is of critical importance for the development of novel, energy efficient magnetic memory devices. Transitions between stable magnetic states can follow various pathways which are not equivalent in terms of efficiency and required time. In this study, we propose a general theoretical approach to design external field pulses for efficient switching between magnetic states. The approach involves calculation of a minimum energy path (MEP) for desired magnetic transition and systematic identification of the temporal and spatial shape of the pulse needed to drive the system along the MEP.
The approach is applied to the magnetization switching in the atomically-thin Fe nanowires on Cu2N surface, a system that has previously been studied extensively in the laboratory [1]. Short nanowires reverse their magnetization via coherent rotation which is induced by applying a uniform magnetic field. Transitions in longer chains involve nucleation and propagation of transient domain walls, for which a localized, time-dependent pulse needs to be applied. Our results demonstrate that efficient switching pulses can be predicted from first principles, contributing to the development of low-power technologies.
[1] A. Spinelli et al., Nature Mater. 13, 782 (2014).