Oral presentation

Session Information

Location: Science and Cultural Center - FORTH
Day: 3. Friday 18th
Time: 10:10-10:30
Chairperson: to be announced…

Presentation Details

Presentation Type: Oral presentation
Title: Magnetostatic interaction to stabilise the magnetic textures in nanostructures
Abstract: Magnetostatic interactions are a ubiquitous feature of ferromagnetic nanostructures. Through the use of analytical modelling and micromagnetic simulations, we present two methods for controlling and stabilising topologically protected magnetic textures within ultrathin nanostructures, by means of spatially engineered magnetostatic fields produced by a hard ferromagnetic nanostructure. Firstly, we show that the stray fields from a Co/ Pd ferromagnetic ring with perpendicular magnetic anisotropy (PMA) can significantly enhance the stability of a Néel-type skyrmion in a ferromagnetic nanodot with PMA. This enhancement can stabilise the skyrmion even in the absence of Dzyaloshinskii–Moriya interactions (DMI). We also show that shaping the ring enables precise control over skyrmion size and stability. This includes the ability to induce multistability, whereby the skyrmion can be stabilised at two or more distinct equilibrium diameters depending on the magnetisation orientation of the ring. These stable states exhibit energy barriers that substantially exceed thermal fluctuations at room temperature, suggesting potential applications in robust multibit memory storage. Secondly, we show that the magnetic field generated by a PMA multilayer nanodot can stabilise a radial vortex in a thin permalloy disk deposited just above the multilayer. This system exhibits high-frequency gyrotropic oscillations of up to 10 GHz without an external bias magnetic field and this can be increased further by anisotropy or DMI, offering promising solutions for microwave applications.

Presenter

Prof Maciej Krawczyk
Adma Mickiewicz University, Poznan | Poland

Authors

1. Krawczyk, Maciej | Institute of Spintronics and Quantum Information, Faculty of Physics and Astronomy, Adam Mickiewicz University, Poznan, Poland