SPICE Workshop on Nanomagnetism in 3D, April 30th - May 2nd 2024
Jiadong Zang
Chiral magnets are a series of magnets with broken inversion symmetry. A new type of spin interaction therein, the Dzyaloshinskii-Moriya interaction, stimulates the formation of many novel topological spin textures. One important example is the emergence of magnetic skyrmion, whose nontrivial topology enables unique dynamical property and thermal stability and gives rise to promising applications in future spintronic devices.
In the first part of the talk, I will give a pedagogical overview of the formation and dynamics of skyrmions and other skyrmion-related textures. I will generalize the skyrmion texture from two dimensions (2D) to three dimensions (3D), and discuss skyrmionic 3D spin textures in chiral magnets, including target skyrmion, skyrmion bundle, and skyrmionic vortices. I will also discuss the magnetic hopfion, a rigorously defined 3D topological texture. We propose the presence of zero-field hopfion in synthetic chiral magnetic multilayers. All these 3D textures exhibit novel dynamical properties that can be formulated in terms of collective coordinates. These works could stimulate the development of 3D spintronics.
Reference:
1. W. Wang, D. Song, W. Wei, P. Nan, S. Zhang, B. Ge, M. Tian, J. Zang, H. Du, Electrical manipulation of skyrmions in a chiral magnet, Nature Communications, 13, 1593 (2022)
2. K. Niitsu, Y. Liu, A. C. Booth, X. Yu, N. Mathur, M. J Stolt, D. Shindo, S. Jin, J. Zang, N. Nagaosa, Y. Tokura, Geometrically stabilized skyrmionic vortex in FeGe tetrahedral nanoparticles, Nature Materials 21, 305 (2022),
3. D. Song, W. Wang, J. X. Yu, P. Zhang, S. S. Pershoguba, G. Yin, W. Wei, J. Jiang, B. Ge, X. Fan, M. Tian, A. Rosch, J. Zang, H. Du, Experimental observation of one-dimensional motion of interstitial skyrmion in FeGe, arXiv:2212.08991
4. Y. Liu, R. K. Lake, J. Zang, Binding a hopfion in a chiral magnet nanodisk, Physical Review B 98 (17), 174437 (2018).
5. Y. Liu, W. Hou, X. Han, J. Zang, Three-dimensional dynamics of a magnetic hopfion driven by spin transfer torque, Physical review letters 124, 127204 (2021).