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3D topological spin textures in magnetic multilayers

ORAL

Abstract

Magnetic Skyrmions are topological spin textures that are scientifically interesting and hold promise for low-power information technology devices. Although their properties are well understood in the framework of 2D systems, in real materials the extension of skyrmions into the 3rd dimension cannot be neglected and has opened a plethora of novel topological spin textures. Among those spin textures are skyrmion tubes, chiral bobbes, magnetic cocoons, torons and also magnetic Hopfions [1]. Target Skyrmions [2] have been predicted [3] to be precursors of magnetic Hopfions in magnetic multilayers and have recently been experimentally verified using complementary surface and bulk sensitive magnetic soft x-ray microscopies [4].

Here, we present results of magnetic X-ray laminography [5] recorded at the Pollux end station at the Swiss Light Source. Full 3D renderings of chiral spin textures in magnetic Pt/Co/Ir multilayers provide detailed insight into underlying interactions in those spin textures.

In addition to their static character, the fast dynamics, which can be triggered e.g., by current [6] or field [7] pulses are also of great interest. Micromagnetic simulations indicate a field driven transition from a Hopfion to a toron state.

Publication: [1] P. Sutcliffe, "Let's twist again," Nat Mater, vol. 16, no. 4, pp. 392–393, 2017, doi: 10.1038/nmat4883.<br>[2] N. Kent et al., "Generation and stability of structurally imprinted target skyrmions in magnetic multilayers," Appl Phys Lett, vol. 115, no. 11, p. 112404, S­­­­­­­ep. 2019, doi: 10.1063/1.5099991.<br>[3] P. Sutcliffe, "Hopfions in chiral magnets," J Phys A Math Theor, vol. 51, no. 37, p. 375401, 2018, doi: 10.1088/1751-8121/aad521.<br>[4] N. Kent et al., "Creation and observation of Hopfions in magnetic multilayer systems," Nat Commun, vol. 12, no. 1, p. 1562, 2021, doi: 10.1038/s41467-021-21846-5.<br>[5] C. Donnelly et al., "Experimental observation of vortex rings in a bulk magnet," Nat Phys, vol. 17, no. 3, pp. 316–321, 2021, doi: 10.1038/s41567-020-01057-3.<br>[6] Y. Liu, W. Hou, X. Han, and J. Zang, "Three-Dimensional Dynamics of a Magnetic Hopfion Driven by Spin Transfer Torque," Phys Rev Lett, vol. 124, no. 12, p. 127204, Mar. 2020, doi: 10.1103/PhysRevLett.124.127204.<br>[7] D. Raftrey and P. Fischer, "Field-Driven Dynamics of Magnetic Hopfions," Phys Rev Lett, vol. 127, no. 25, p. 257201, Dec. 2021, doi: 10.1103/PhysRevLett.127.257201.

Presenters

  • David Raftrey

    University of California, Santa Cruz

Authors

  • David Raftrey

    University of California, Santa Cruz

  • Peter J Fischer

    Lawrence Berkeley National Laboratory

  • Simone Finizio

    PSI, Paul Scherrer Institute

  • Jörg Raabe

    PSI, Paul Scherrer Institute

  • Tiffany S Santos

    Western Digital Research Center, Western Digital Corporation, San Jose, CA

  • Scott Dhuey

    Lawrence Berkeley National Laboratory