Direct Observation of Chiral Bobbers in Nanostructured FeGe

ORAL

Abstract

Chiral magnets represent a special class of magnetically ordered crystals that are characterized by broken inversion symmetry and strong spin-orbit coupling, giving rise to the Dzyaloshinskii-Moriya interaction (DMI). The presence of the DMI usually prevents the stability and coexistence of topological excitations of different types. However, recently a new type of localized particle-like object -- the chiral bobber (ChB) - was predicted theoretically in such materials1. Such hybrid particle-like states are composed of continuum magnetization vector fields and singularities that are known as Bloch points. Here, we report the experimental observation of ChBs in thin films of B20-type FeGe by means of quantitative off-axis electron holography2, which allowed us to identify the part of the temperature-field magnetic phase diagram, in which ChBs exist and to identify two distinct mechanisms for their nucleation. We show that ChBs are able to coexist with skyrmions over a wide range of parameters, suggesting their possible practical application in novel magnetic solid state memory devices, in which a stream of binary data bits can be encoded by a sequence of skyrmions and bobbers2.
[1] F. N. Rybakov et al. Phys. Rev. Lett. 115, 117201 (2015).
[2] F. Zheng et al. arXiv:1706.04654

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Presenters

  • Nikolai S. Kiselev

    • Peter Grünberg Institute and Institute for Advanced Simulation, Forschungszentrum Jülich
    • Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA

Authors

  • Nikolai S. Kiselev

    • Peter Grünberg Institute and Institute for Advanced Simulation, Forschungszentrum Jülich
    • Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA

  • Fengshan Zheng

    • Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich

  • Filipp Rybakov

    • Physics, KTH-Royal Institute of Technology

  • Aleksandr Borisov

    • M.N. Miheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences

  • Dongsheng Song

    • National Center for Electron Microscopy in Beijing, School of Materials Science and Engineering, Tsinghua University

  • Shasha Wang

    • Collaborative Innovation Center of Advanced Microstructures, Nanjing University

  • Zi-An Li

    • Institute of Physics, Chinese Academy of Sciences

  • Haifeng Du

    • The Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, Chinese Academy of Science

  • Jan Caron

    • Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich

  • Mingliang Tian

    • The Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, Chinese Academy of Science

  • Yuheng Zhang

    • The Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, Chinese Academy of Science

  • Stefan Bluegel

    • Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA
    • Peter Grünberg Institute and Institute for Advanced Simulation, Forschungszentrum Jülich
    • Peter Grünberg Institut, Forschungszentrum Jülich
    • Peter Grünberg Institut (PGI) and Institute for Advanced Simulation (IAS), Forschungszentrum Jülich and JARA
    • PGI-1, Forschungszentrum Jülich
    • Forschungszentrum Julich GmbH
    • PGI-1, FZ Juelich

  • Rafal Dunin-Borkowski

    • Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich