Regensburg 2019 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 54: Magnetic textures: Transport and dynamics III
MA 54.8: Vortrag
Freitag, 5. April 2019, 11:30–11:45, H37
On rate theory for continuous multidimensional magnetic systems — •Grzegorz Kwiatkowski1,2 and Pavel F. Bessarab1,3 — 1University of Iceland, Reykjavík, Iceland — 2Immanuel Kant Baltic Federal University, Kaliningrad, Russia — 3ITMO University, St. Petersburg, Russia
The search for optimal magnetic memory bits combining high stability and energy-efficient writability is a key problem in the field of future information technologies. In this respect, designing samples characterized by low attempt frequency appears to be particularly promising. Here we demonstrate that internal degrees of freedom have a crucial impact on thermal stability of magnetic systems. Due to the effect of the internal modes, even monodomain particles which reverse their magnetization by strictly uniform rotation can have much lower attempt frequency compared to the values predicted by the rate theory due to Néel and Brown [1,2]. Our results also demonstrate the need for revision of classical rate theories for 2D- and 3D-systems due to inherent divergent behaviour. We propose a generalization of the rate theories for continuum systems in line with ideas of Debye [3] and present illustrative examples. Our results are particularly important for describing the thermal stability of magnetic skyrmions which are praised to be the information-carrying bits in next-generation data storage and logic devices.
L. Néel, Ann. Geophys. 5, 99 (1949).
W. F. Brown, Phys. Rev. 130, 1677 (1963).
P. Debye, Ann. Phys. 344, 14 (1912).