Emergence of Magnetic Skyrmions in Ferromagnetic Transition Metal Chalcogenides

ORAL

Abstract

Van der Waals magnets have drawn great attention since the discovery of intrinsic 2D ferromagnetism. Due to the extraordinary correlations among charge, spin, orbital and lattice degrees of freedom, layered magnetic transition metal chalcogenides (TMCs) is a rich area for uncovering exotic topological phenomena. Particularly, magnetic skyrmions have high potential for ultra-dense memory and logic devices while skyrmions are yet to be experimentally found in TMC monolayers (MLs) despite theoretical predictions. Here we report the realization of quasi-2D TMC Cr2Te3 down to 1 ML on SrTiO3 (111) by molecular beam epitaxy (MBE). The spin-glass behavior in thick films has enabled the investigation of magnetic skyrmions in the ML limit, while robust ferromagnetism survives in insulating ML film (Tc =17 K). Topological Hall effect and unusual hysteresis observed in transport/magnetometry measurements unveil the emergence of stable magnetic skyrmions, down to 1 ML. The unique concomitant occurrence of 2D ferromagnetism and skyrmionic behavior in ultrathin Cr2Te3 films widens TMC-based material possibilities for various quantum hybrid studies.

*This work was supported by NSF (DMR 1700137), ONR (N00014-16-1-2657 and N00014-20-1-2306), and CIQM (DMR-1231319) and ARO (W911NF-19-2-0015).

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Presenters

  • Yunbo Ou

    • Massachusetts Institute of Technology
    • Francis Bitter Magnet Laboratory, Plasma Science and Fusion Center, Massachusetts Institute of Technology

Authors

  • Yunbo Ou

    • Massachusetts Institute of Technology
    • Francis Bitter Magnet Laboratory, Plasma Science and Fusion Center, Massachusetts Institute of Technology

  • Hang Chi

    • Massachusetts Institute of Technology
    • Francis Bitter Magnet Laboratory, Plasma Science and Fusion Center, Massachusetts Institute of Technology

  • Norbert Marcel Nemes

    • Departamento de Fisica de Materiales, Universidad Complutense de Madrid

  • Jose Luis Martinez

    • Instituto de Ciencia de Materiales de Madrid ICMM-CSIC

  • Mirko Rocci

    • NEST, Instituto Nanoscienze-CNR and Scuola Normale Superiore
    • Francis Bitter Magnet Laboratory, Plasma Science and Fusion Center, Massachusetts Institute of Technology

  • Austin Akey

    • Harvard University
    • Center for Nanoscale Systems, Harvard University

  • Wenbo Ge

    • Department of Physics and Astronomy, Rutgers University

  • Dhavala Suri

    • Tata Institute of Fundamental Research (TIFR)
    • TIFR Centre for Interdisciplinary Sciences
    • Francis Bitter Magnet Laboratory, Plasma Science and Fusion Center, Massachusetts Institute of Technology

  • Yiping Wang

    • Department of Physics, Boston College

  • Kenneth Burch

    • Physics, Boston University
    • Physics, Boston College
    • Boston College
    • Department of Physics, Boston College

  • David Charles Bell

    • School of Engineering and Applied Sciences, Harvard University

  • Weida Wu

    • Rutgers Department of Physics and Astronomy, Rutgers University, Piscataway, NJ, USA
    • Department of Physics and Astronomy, Rutgers, The State University of New Jersey
    • Rutgers University
    • Department of Physics and Astronomy, Rutgers University

  • Jagadeesh S Moodera

    • Massachusetts Institute of Technology
    • Plasma Science and Fusion Center, and Francis Bitter Magnet Laboratory, and Department of Physics,, Massachusetts Institute of Technology
    • Physics, Massachusetts Institute of Technology
    • Department of Physics, Massachusetts Institute of Technology