Skyrmionics: Second Transformation of Spin Era

A magnetic skyrmion is a particle-like topological spin texture, where the forming nots are key parameters to hold its topology. Its existence has been proposed in a system with low symmetry since late 80’s and especially MnSi in 2006[1], and the experimental proof of this structure in crystalline form has come out in 2009[2]. After that, isolated magnetic skyrmion has been the main target since each magnetic skyrmion can carry the information in all kinds of devices. Especially, it has drawn a lot of attention for its potential use in spintronic devices. From memory to logic devices, its manipulations(creation, deletion, movement) with pure electric external variables are most demanding. Contrary to its expectation for the appearance of a revolutionary device, even the generation of this magnetic skyrmion at the place aimed has not been possible. Recently we have shown several unique methods for the generation and manipulation of this magnetic skyrmion based on the detailed skyrmion formation process[3-5]. With these methods, we can demonstrate several skyrmionic devices[6-8] such as skyrmion racetrack memory, skyrmion transistor, and skyrmion neuromorphic device. Our next step is leading the quantum effects with magnetic skyrmions. What we need at this stage is to decrease its size. With the consideration of shrinking its size down to the scales of lattice spacing, we can discuss several examples of quantum skyrmions.

[1] A. N. Bogdanov, D. A. Yablonskii, Zh Eksp Teor Fiz. 95, 178 (1989), U. K. Rößler et al., Nature 442, 797 (2006)

[2] S. Mu¨hlbauer et al. Science, 323, 915(2009).

[3] K.-W. Moon et al., NPG Asia Materials 13, 20 (2021)

[4] S. Yang et al., JMMM 539, 168381(2021)

[5] S. Yang, Nano Letters accepted (2022)

[6] S. Yang et al., Adv. Mater. 33, 2104406(2021)

[7] M. Song et al., Adv. Mater. 34, 2270277(2022)

[8] under review