Domain wall dynamics in metallic and insulating ferrimagnets

ORAL

Abstract

In ferromagnet systems, engineered interfaces can give rise to the chiral Dzyaloshinskii-Moriya interaction (DMI) in otherwise symmetric systems1. Research has primarily focused on the study of chiral solitons in metallic systems, where heavy metal underlayers provide a large spin-orbit torque and an interfacial DMI. This resulted in extensive research of chiral solitons in ferromagnetic systems1,2. However, damping in metals is generally high, which limits soliton mobility. The low damping and ferrimagnetic dynamics of insulating garnets make them ripe candidates for ultrafast spin textures. Moreover, spin-orbit effects and spin-transport phenomenon from adjacent heavy metal layers have been used to manipulate the magnetisation in these materials3. Here, we use a pure spin current from an adjacent Pt overlayer to characterise chiral domain wall motion and DMI in epitaxial iron garnet films with perpendicular magnetic anisotropy. We use the significant interfacial DMI and a large spin-orbit torque to drive chiral domain walls to record velocities of a few thousand meters per second.
1 Emori, S. et al. Nat. Mater. 12, 611–616 (2013)
2 Woo, S. et al. Nat. Mater. 15, 501–506 (2016)
3 Avci, C. O. et al. Nat. Mater. 16, 309–314 (2017)

*DARPA TEE program & SMART, an nCORE Center.

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Presenters

  • Lucas Caretta

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

Authors

  • Lucas Caretta

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

  • Ethan Rosenberg

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

  • Takian Fakhrul

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

  • Se-Hyeok Oh

    • Department of Nano-Semiconductor and Engineering, Korea University

  • Dong-Kyu Lee

    • Materials Science and Engineering, Korea University

  • Felix Buettner

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

  • Pierluigi Gargiani

    • ALBA Synchrotron

  • Manuel Valvidares

    • ALBA Synchrotron

  • Se Kwon Kim

    • Univ of Missouri
    • Department of Physics and Astronomy, University of Missouri, Columbia
    • Department of Physics and Astronomy, University of Missouri
    • Univ of Missouri - Columbia

  • Caroline Ross

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

  • Kyung-Jin Lee

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

  • Geoffrey Beach

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