Topological Magnetic-Spin Structures in Two-Dimensional Van Der Waals Cr<sub>2</sub>Ge<sub>2</sub>Te<sub>6</sub>

ORAL

Abstract

Long-range ferromagnetic order down to atomic layers provides an important degree of freedom in engineering two-dimensional (2D) materials and their heterostructure devices for spintronics, valleytronics and magnetic tunnel junction switches. Using direct imaging by cryo-Lorentz transmission electron microscopy we report that topologically nontrivial magnetic-spin states, skyrmionic bubbles, can be realized in exfoliated insulating 2D van der Waals Cr2Ge2Te6. Due to the competition between dipolar interactions and uniaxial magnetic anisotropy, hexagonally-packed nanoscale bubble lattices emerge in the ab plane by field cooling. Despite a range of topological spin textures arising due to pair formation and annihilation of Bloch lines, bubble lattices with single chirality are prevalent. Our observation of topologically-nontrivial homochiral skyrmionic bubbles in exfoliated vdW materials provides a new avenue for novel quantum states in atomically-thin insulators for magneto-electronic and quantum devices.

*This work was supported by the US Department of Energy, Basic Energy Sciences, Materials Sciences and Engineering Division (Contract No. DE-SC0012704).

–

Presenters

  • Myung-Geun Han

    • Condensed Matter Physics and Materials Science, Brookhaven National Laboratory
    • Brookhaven National Laboratory

Authors

  • Myung-Geun Han

    • Condensed Matter Physics and Materials Science, Brookhaven National Laboratory
    • Brookhaven National Laboratory

  • Joseph Garlow

    • Brookhaven National Laboratory

  • Yu Liu

    • Brookhaven National Laboratory

  • Huiqin Zhang

    • Electrical and Systems Engineering, University of Pennsylvania
    • Department of Electrical and System Engineering, University of Pennsylvania

  • Donald DiMarzio

    • NG Next, Northrop Grumman Corporation

  • Mark Knight

    • Northrop Grumman Corporation
    • NG Next, Northrop Grumman Corporation

  • Cedomir Petrovic

    • Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory
    • Brookhaven National Laboratory
    • Condensed Matter Physics and Materials Science, Brookhaven National Laboratory
    • Condensed Matter Physics & Materials Science Department, Brookhaven National Laboratory
    • Brookhaven National Laboratory, NY 11973, USA

  • Deep Jariwala

    • Department of Electrical and System Engineering, University of Pennsylvania

  • Yimei Zhu

    • Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory
    • Brookhaven National Laboratory
    • Brookhaven National Lab
    • Condensed Matter Physics and Materials Science, Brookhaven National Laboratory
    • Department of Energy Science and Technology, Brookhaven National Laboratory