2D Layered Ferromagnet: the Emergence of Skyrmions in Transition Metal Dichalcogenides

ORAL

Abstract

Recently there is great attraction drawn towards Van der Waals (vdW) ferromagnet since the discovery of ferromagnetism in monolayer CrI3. Due to the extraordinary topology driven properties, magnetic transition metal dichalcogenides (TMDCs) appear to behave more exotically. In this work, utilizing molecular beam epitaxy, a stable CrTe2, one of TMDCs, films are fabricated down to monolayer (ML) level. Ferromagnetism is exhibited even down to the 2D insulating limit - 1 ML film. Surprisingly, the topological Hall effect (THE), which manifests the real space topology of magnetic structure in TMDCs, is observed in thicker films (> 6 ML) up to 130 K, a first such observation. Electric transport data and magnetometry data indicate a high possibility of presence of magnetic Skyrmions, real space nanometer-sized quasi-particles with topological spin textures. Although they are found in many systems even at room temperature, but not in TMDCs, until now. The discovery of magnetism in monolayer CrTe2 and topological magnetic structure in thicker CrTe2 not only enriches the 2D magnet family and the capability of TMDCs, but also pave a way for all vdW materials based spintronic devices.

*Supported by NSF (NSF-DMR 1700137), ONR (N00014-16-1-2657), CIQM (DMR-1231319) and ARO (ARO W911NF1920041).

Presenters

  • Yunbo Ou

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

Authors

  • Yunbo Ou

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

  • Norbert Marcel Nemes

    • Unidad Asociada ICMM-CSIC “Laboratorio de Heteroestructuras con Aplicación en Espintrónica”,, Complutense University of Madrid
    • Fisica de los Materiales, Universidad Complutense de Madrid and ICMM-CSIC

  • Jose Luiz Martinez

    • Instituto de Ciencia de Materiales de Madrid ICMM-CSIC
    • Instituto de Ciencia de Materiales de Madrid - CSIC

  • Mirko Rocci

    • Francis Bitter Magnet Laboratory, Plasma Science and Fusion Center, Massachusetts Institute of Technology
    • MASSACHUSETTS INSTITUTE OF TECHNOLOGY
    • Massachusetts Institute of Technology MIT

  • HANG CHI

    • Francis Bitter Magnet Laboratory, Plasma Science and Fusion Center, Massachusetts Institute of Technology
    • Plasma Science and Fusion Center, and Francis Bitter Magnet Laboratory, and U.S. Army CCDC, MIT and Army Research Laboratory

  • Daniel Larson

    • Department of Physics, Harvard University
    • Harvard University

  • Austin Akey

    • Center for Nanoscale Systems, Harvard University

  • Wenbo Ge

    • Department of Physics and Astronomy, Rutgers University

  • Dhavala Suri

    • Francis Bitter Magnet Laboratory, Plasma Science and Fusion Center, Massachusetts Institute of Technology
    • Plasma Science and Fusion Center, and Francis Bitter Magnet Laboratory, MIT
    • MASSACHUSETTS INSTITUTE OF TECHNOLOGY
    • Massachusetts Institute of Technology MIT

  • David Charles Bell

    • School of Engineering and Applied Sciences, Harvard University
    • Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University
    • Harvard University

  • Weida Wu

    • Physics and Astronomy, Rutgers University, New Brunswick
    • Department of Physics and Astronomy, Rutgers University
    • Department of Physics and Astronomy, Rutgers, The State University of New Jersey
    • Department of Physics and Astronomy, Rutgers University, New Brunswick
    • Rutgers University, New Brunswick

  • Efthimios Kaxiras

    • Harvard University
    • Department of Physics, Harvard University

  • Jagadeesh Moodera

    • Department of Physics, Massachusetts Institute of Technology
    • Plasma Science and Fusion Center, and Francis Bitter Magnet Laboratory, and Department of Physics, MIT
    • Massachusetts Institute of Technology
    • MASSACHUSETTS INSTITUTE OF TECHNOLOGY
    • Massachusetts Institute of Technology MIT