Direct imaging of topological phase discontinuities in chiral spin textures via electron ptychography beyond diffraction-limited resolution

ORAL

Abstract

Real-space imaging of magnetic structures can provide crucial information for understanding many magnetic phenomena. Here, utilizing a new electron microscope detector, EMPAD, we resolve the internal fine structure of skyrmions in single crystal FeGe using Lorentz STEM and electron ptychography. We have unambiguously uncovered the topological phase discontinuities near the skyrmion lattice dislocation and boundaries. We also demonstrate a significant resolution improvement using electron ptychography, allowing magnetic imaging beyond the diffraction limit imposed by the electron optics. Magnetic domain images from ultrathin metallic multilayer films show the outstanding detection limit of our new imaging method. This new direct imaging technique can be applied to determine complex chiral spin structures in a wide variety of materials.

*Supported by NSF DMR-1539918 and MRSEC DMR-1719875 and DARPA D18AC00009

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Presenters

  • Zhen Chen

    • Applied and Engineering Physics, Cornell University

Authors

  • Zhen Chen

    • Applied and Engineering Physics, Cornell University

  • Emrah Turgut

    • Department of Physics, Oklahoma State University

  • Krishnan Chander

    • Applied and Engineering Physics, Cornell University

  • Kayla Nguyen

    • Applied and Engineering Physics, Cornell University

  • Matthew Stolt

    • University of Wisconsin–Madison

  • Song Jin

    • Chemistry, University of Wisconsin-Madison
    • University of Wisconsin–Madison

  • Dan Ralph

    • Cornell University
    • Department of Physics, Cornell University
    • Physics, Cornell University

  • Gregory Fuchs

    • Cornell University
    • Applied and Engineering Physics, Cornell University
    • School of Applied and Engineering Physics, Cornell University

  • David Anthony Muller

    • School of Applied and Engineering Physics, Cornell University
    • Cornell University
    • Applied and Engineering Physics, Cornell University