Micromagnetic Simulation Insights into the Coexistence of Neel and Bloch Skyrmions in [Pt/Co/Cu]<sub>N</sub> Multilayers
POSTER
Abstract
Magnetic skyrmions are one of the most promising candidates for next-generation information storage due to their small sizes, thermal stability, and high energy efficiency. Recently we have discovered magnetic skyrmions in epitaxial [Pt/Co/Cu]N multilayers using magnetic force microscopy (MFM) and Lorentz transmission electron microscopy (LTEM) [1]. In our LTEM experiments on the devices patterned from [Pt/Co/Cu]5 multilayers, we have found that the Bloch and Neel skyrmions can coexist upon applying current pulses. To understand this behavior, we have performed micromagnetic simulations in which [Pt/Co/Cu]N multilayers are modeled as a stack of 3*N layers. With this micromagnetic model, we are able to reproduce several major experimental observations: (1). Out-of-plane single domain to multidomain transition between N = 4 to N = 5. (2). The diameter of skyrmions in [Pt/Co/Cu]5 multilayers, which is ~120 nm. (3). The inherent coexistence of Neel and Bloch skyrmions that undergoes a transition with applied pulse current.
*This work was supported by the DARPA TEE program under Grant No. D18AP00008. This research was partially supported by the Center for Emergent Materials, an NSF MRSEC, under award number DMR-2011876. Electron microscopy was performed at the Center for Electron Microscopy and Analysis (CEMAS) at The Ohio State University.
Publication: arXiv preprint arXiv:2303.02117
Presenters
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Shuyu Cheng
- The Ohio State University
- The Ohio State University, Department of Physics