Universal high-speed dynamics of distorted bubble skyrmions in an uncompensated amorphous ferrimagnet

ORAL

Abstract

Magnetic skyrmions are topologically stabilized spin configurations that, like domain walls (DWs), can react to external stimuli by collective displacement, which is both physically intriguing and bears promises to realize next generation non-volatile data storage technologies.
Analytical equations of motion describe straight 180° DWs in the one-dimensional (1D) model while rigid, circular bubble domains and skyrmions move according to the Thiele equation. However, DWs and skyrmions are often not perfectly straight or circular.
Here, we study how strongly deformed DWs and bubble skyrmions move in uncompensated ferrimagnetic Pt/CoGd/W in response to current pulses. We find that all 1D spin textures exhibit velocity saturation at ~300 m/s in agreement with the 1D model, while all fully enclosed spin textures, even if significantly distorted, reach >500 m/s. We attribute this significant difference in the dynamics to the topology and the canting of spins in the skyrmion’s encircling DWs.

*DARPA TEE program. Devices were fabricated using equipment in the MIT Microsystems Technology Laboratory and the MIT Nanostructures Laboratory.

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Presenters

  • Kai Litzius

    • Massachusetts Institute of Technology MIT

Authors

  • Kai Litzius

    • Massachusetts Institute of Technology MIT

  • Felix Buettner

    • Massachusetts Institute of Technology MIT
    • Materials Science and Engineering, Massachusetts Institute of Technology (MIT)

  • Angela Wittmann

    • Massachusetts Institute of Technology MIT

  • Wei Zhou

    • Department of Physics, University of Virginia
    • Electrical and Computer Engineering, Virginia Tech

  • Chung T Ma

    • Department of Physics, University of Virginia

  • Joachim Graefe

    • Max Planck Institute for Intelligent Systems

  • Nick-André Traeger

    • Max Planck Institute for Intelligent Systems

  • Simone Finizio

    • Swiss Light Source, Paul Scherrer Institut

  • Daniel Suzuki

    • Massachusetts Institute of Technology MIT

  • Siying Huang

    • Massachusetts Institute of Technology MIT

  • Lucas Caretta

    • Massachusetts Institute of Technology MIT
    • Materials Science and Engineering, Massachusetts Institute of Technology (MIT)
    • University of California, Berkeley

  • Mantau Huang

    • Massachusetts Institute of Technology MIT

  • Yassine Quessab

    • Department of Physics, New York University

  • Hans Nembach

    • Quantum Electromagnetics Division, National Institute of Standards and Technology
    • NIST and University of Colorado

  • Grant A Riley

    • Quantum Electromagnetics Division, National Institute of Standards and Technology

  • Justin Shaw

    • National Institute of Standards and Technology Boulder
    • Quantum Electromagnetics Division, National Institute of Standards and Technology

  • Andrew Kent

    • Department of Physics, New York University
    • Center for Quantum Phenomena, Department of Physics, New York University
    • New York University

  • Gisela Schuetz

    • Max Planck Institute for Intelligent Systems

  • Joseph Poon

    • Department of Physics, University of Virginia

  • Geoffrey Beach

    • Massachusetts Institute of Technology MIT
    • Materials Science and Engineering, Massachusetts Institute of Technology (MIT)