Observation of room temperature polar bubbles/ skyrmions in oxide heterostructures

ORAL

Abstract

The complex non-collinear and non-coplanar topological textures in complex oxides have recently attracted of their various exotic phenomena (such as emergent structural chirality). Among them the recent discovery of polarization vortices with toroidal order in superlattices of (PbTiO3)n/(SrTiO3)n [1]. Topologically protected nanometric polar vortices, skyrmions are being are rarely investigated in complex heterostructures. Here, we describe that for a room-temperature polar bubbles/skyrmions with 6-7 nm size in PbTiO3/SrTiO3 heterostructures via real space imaging transmission electron microscopy, phase field simulations and ab-initio calculations. Phase-field and ab-initio studies have revealed the presence of this new polarization topology of ferroelectric bubbles/skyrmions that arise from a combination of epitaxial strain and layer thickness. This finding of nanometre-scale polar topology in a thin film may be useful as a fertile ground for promising applications.

[1] Yadav, A. K. et al. Observation of polar vortices in oxide superlattices. Nature 530, 198-201 (2016).

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Presenters

  • SUJIT DAS

    Department of Materials Science & Engineering, University of California, MSE, UC Berkeley

Authors

  • SUJIT DAS

    Department of Materials Science & Engineering, University of California, MSE, UC Berkeley

  • Y. L Tang

    Materials Science Division, Lawrence Berkeley National Laboratory, MSE, UC Berkeley

  • S.-L. Hsu

    Department of Materials Science & Engineering, University of California, MSE, UC Berkeley, Department of Materials Science & Engineering, University of California, Berkeley

  • A. Ghosh

    Department of Materials Science & Engineering, University of California, MSE, UC Berkeley

  • M. R. McCarter

    Department of Physics, University of California

  • Z. Hong

    Department of Materials Science and Engineering , Pennsylvania State University

  • Y. Dong

    National Center for Electron Microscopy, Lawrence Berkeley National Laboratory

  • L.-Q. Chen

    Department of Materials Science and Engineering , Pennsylvania State University

  • D. D. Fong

    Materials Sciences Division, Argonne National Laboratory

  • J. Junquera

    Departmento de Ciencias de la Tierra y Física de la Materia Condensada, Universidad de Cantabria

  • L.W. Martin

    Department of Materials Science & Engineering, University of California

  • R. Ramesh

    Department of Materials Science & Engineering, University of California