ABSTRACT

Magnetic skyrmions are nano-metric topologically protected spin structures [1, 2], which can be used in next-generation nonvolatile memories and spin logic devices [3, 4]. However, there exists a significant obstacle to applications, that is, the presence of the skyrmion Hall effect (SkHE) [4]. Namely, the deviation of skyrmion motion from the driving current direction due to a topological Magnus force associated with its topological charge. In this talk, I will demonstrate the suppression of the SkHE in an antiferromagnetically exchange-coupled magnetic bilayer, by exactly cancelling the topological Magnus forces of skyrmions in the top and bottom layers [5, 6]. Furthermore, the dynamics of a synthetic antiferromagnetic skyrmion in a bilayer, including its creation, manipulation enabled by the current-induced spin Hall torque will be discussed. Our work is important to understand the dynamics of magnetic skyrmion and provides a promising pathway to construct future skyrmion-based spintronic devices.

REFERENCES

[1] N. Nagaosa and Y. Tokura, Nature Nanotechnology 8, 899 (2013).

[2] R. Wiesendanger, Nature Reviews Materials 1, 16044 (2016).

[3] X. Zhang, M. Ezawa, and Y. Zhou, Scientific Reports 5, 9400 (2015).

[4] W. Jiang et al., Nature Physics advance online publication, (2016).

[5] X. Zhang, Y. Zhou, and M. Ezawa, Nature Communications 7, 10293 (2016).

[6] X. Zhang, M. Ezawa, and Y. Zhou, Physical Review B 94, 064406 (2016).

ABOUT THE SPEAKER

Xichao Zhang received the B.S. degree from Sichuan Normal University in 2014. He was a Research Assistant with The University of Hong Kong since 2014. Currently, Mr. Zhang is a PhD student at Shinshu University, Japan. He is also a Research Assistant with The Chinese University of Hong Kong, Shenzhen. His research interests lie in the theories of nano-magnetism and spintronics. He has published more than 20 papers, including 10 first-author papers in Nature Physics, Nature Communications, Scientific Reports, Physical Review B, Nanotechnology, etc.