Observation of room-temperature polar skyrmions in oxide superlattice

ORAL

Abstract

Recent discovery of polarization flux closures, vortices and skyrmions in polar oxide superlattices suggests the presence of a complex, multi-dimensional system capable of exotic physical responses[i],[ii],[iii], where the exploration of novel emergent phenomena and exotic phases in condensed-matter physics is greatly facilitated. Here, we have observed a room-temperature polar skyrmions in a PbTiO3/SrTiO3 superlattices grown on SrTiO3(001) substrate. X-Ray diffraction and large scale scanning transmission electron microscopy imaging confirmed the present of the polar skyrmions phase. In addition, phase-field modeling and second-principles calculations reveal that the polar skyrmions have a skyrmion number of +1. Moreover, special uniform chirality was revealed by resonant soft X-ray diffraction experiments showing obvious circular dichroism. Such nanometer-scale polar skyrmions are the electric analogs of magnetic skyrmions, and could advance ferroelectrics towards new levels of functionality.
[i] Das, S., Tang, Y. L. et. al, Nature (under reviw)；[ii] Yadav, A. K. et. al, Nature 530, 198-201 (2016).；[iii] Shafer, P., García-Fernández. P. et al., Proc. Natl. Acad. Sci. USA 115, 915 (2018).

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Presenters

  • YUNLONG TANG

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

Authors

  • YUNLONG TANG

    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

  • Zijian Hong

    The Pennsylvania State University, University Park, Pennsylvania 16802, USA

  • M. A. P. Gonçalves

    Luxembourg Institute of Science and Technology (LIST), 5 avenue des Hauts-Fourneaux, L-4362 Esch/Alzette, Luxemburg.

  • 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.

  • Christoph Klewe

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

  • F. Gómez-Ortiz

    Universidad de Cantabria, Cantabria Campus Internacional, Avenidad de los Castros s/n, E-39005 Santander, Spain.

  • 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

  • Vladimir A Stoica

    The Pennsylvania State University, University Park, Pennsylvania 16802, USA

  • Shang-Lin Hsu

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

  • B. Wang

    The Pennsylvania State University, University Park, Pennsylvania 16802, USA

  • Colin Ophus

    Molecular Foundry, Lawrence Berkeley National Laboratory, Lawrence Berkeley National Laboratory

  • J. F. Liu

    Lawrence Berkeley National Laboratory

  • Christopher Nelson

    Oak Ridge National Laboratory, Bethel Valley Rd., Tennessee 37831-6071, USA, Oak Ridge National Laboratory

  • Sahar Saremi

    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, Department of Materials Science and Engineering, University of California, Berkeley

  • Bhagwati Prasad

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

  • Darrell G. Schlom

    Cornell University, Cornell University, Ithaca, New York 14853, USA, Department of Materials Science and Engineering, Cornell University, Department of Materials Science and Engineering, Kavli Institute at Cornell for Nanoscale Science, Cornell University, Materials Science & Engineering, Cornell University, Department of Materials Science and Engineering,, Cornell University, Materials Science and Engineering, University of Cornell

  • A. B. Mei

    Cornell University, Ithaca, New York 14853, USA

  • Jorge Iniguez

    LIST, Luxembourg Institute of Science and Technology (LIST), 5 avenue des Hauts-Fourneaux, L-4362 Esch/Alzette, Luxemburg.

  • Pablo Garcia-Fernandez

    Universidad de Cantabria, Cantabria Campus Internacional, Avenidad de los Castros s/n, E-39005 Santander, Spain.

  • Long Q. Chen

    The Pennsylvania State University, University Park, Pennsylvania 16802, USA

  • 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

  • R Ramesh

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