Resonant X-ray diffraction study of chiral polar skyrmions in PbTiO<sub>3</sub>/SrTiO<sub>3</sub> superlattices

ORAL

Abstract

Emergent topologies in ferroelectric heterostructures—the polar analogs of magnetic vortices and skyrmions—have become a recent topic of interest for their potential to host exotic functionalities (e.g., emergent chirality and negative capacitance). These topologies can be stabilized in low-dimensional ferroelectrics; namely, superlattices of PbTiO3/SrTiO3. Polar skyrmion structures have been observed in PbTiO3/SrTiO3 superlattices grown on SrTiO3 substrates with a combination of scanning transmission electron microscopy, X-ray diffraction, and second-principles calculations. Using resonant soft X-ray diffraction, we study the chirality of these polar skyrmions and show that the skyrmions have a preferred handedness. The origin of the circular dichroism is shown to be a chiral configuration of the titanium orbitals in the skyrmions.

*Gordon and Betty Moore Foundation’s EPiQS Initiative, under grant GBMF5307

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Presenters

  • Margaret McCarter

    • Department of Physics, University of California, Berkeley
    • University of California, Berkeley
    • Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA.

Authors

  • Margaret McCarter

    • Department of Physics, University of California, Berkeley
    • University of California, Berkeley
    • Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA.

  • Sujit Das

    • Department of Materials Science and Engineering, University of California at Berkeley
    • Department of Materials Science & Engineering, University of California, Berkeley
    • University of California, Berkeley
    • Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA.
    • Physics Department, Univesity of California, Berkeley

  • Yun-Long Tang

    • Materials Science Division, Lawrence Berkeley National Laboratory
    • University of California, Berkeley

  • Christoph Klewe

    • Advanced Light Source, Lawrence Berkeley National Laboratory
    • Lawrence Berkeley National Laboratory

  • Padraic Shafer

    • Advanced Light Source, Lawrence Berkeley National Laboratory
    • Lawrence Berkeley National Laboratory
    • Advanced Light Source

  • Elke Arenholz

    • Advanced Light Source, Lawrence Berkeley National Laboratory
    • Lawrence Berkeley National Laboratory
    • Advanced Light Source

  • Javier Junquera

    • University of Cantabria
    • Departmento de Ciencias de la Tierra y Física de la Materia Condensada, Universidad de Cantabria
    • Departamento de Ciencias de la Tierra y Física de la Materia Condensada, Universidad de Cantabria, Cantabria Campus Internacional, Avenidad de los Castros s/n, E-39005 Santan
    • Universidad de Cantabria, Cantabria Campus Internacional, Avenidad de los Castros s/n, E-39005 Santander, Spain.

  • Lane Martin

    • Department of Materials Science & Engineering, University of California, Berkeley
    • University of California, Berkeley
    • Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA.
    • Materials Science and Engineering, University of California, Berkeley
    • University of Illinois at Urbana-Champaign

  • Ramamoorthy Ramesh

    • Department of Materials Science & Engineering, University of California, Berkeley
    • University of California, Berkeley