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Negative capacitance in polar skyrmions

ORAL

Abstract

Topological solitons such as magnetic skyrmions have drawn enormous attention as stable quasi-particle-like objects. The recent discovery of polar vortices and skyrmions in ferroelectric oxide superlattices, exhibiting exotic physical phenomena, has opened up new vistas to explore topology, emergent phenomena, and approaches for manipulating such features with electric fields [1,2]. Here, using macroscopic dielectric measurements, phase-field simulations, and second-principles calculations, we demonstrate that polar skyrmions in (PbTiO3)n/(SrTiO3)nsuperlattices are distinguished by a sheath of negative permittivity at the periphery of each skyrmion which enables a strong enhancement of the effective dielectric permittivity as compared to the individual SrTiO3and PbTiO3 layers. Electric-field-dependent X-ray scattering measurements, phase-field simulations, and second-principles calculations are used to determine the relative fraction of skyrmions and quantify the local dielectric susceptibilities. A large, electric-field tunable negative permittivity provides a fundamental framework to enable novel low-power electronics.
1. Das, S et al, Nature 568, 368-372 (2019);
2.Yadav, A. K. et al. Nature 530, 198 (2016);

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Presenters

  • Sujit Das

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

Authors

  • Sujit Das

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

  • Zijian Hong

    Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA

  • Vladimir A Stoica

    Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA

  • Mauro A. P. Gonçalves

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

  • Eric Parsonnet

    University of California, Berkeley

  • Sahar Saremi

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

  • Margaret McCarter

    University of California, Berkeley

  • Armando Reynoso

    University of California, Berkeley

  • Derek Meyers

    University of California, Berkeley, Brookhaven National Laboratory, Oklahoma State University

  • Vishal Ravi

    University of California, Berkeley

  • Hua Zhou

    Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA, Advanced Photon Source, Argonne National Laboratory, Advanced Photon Source, Argonne National Laboratory, Lemont, IL, 60439, USA

  • Zhan Zhang

    Argonne National Lab, Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA, Advanced Photon Source, Argonne National Laboratory

  • Haidan Wen

    Argonne National Laboratory, Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA, Advanced Photon Source, Argonne National Laboratory

  • Fernando Gómez-Ortiz

    Universidad de Cantabria

  • Pablo Garcia-Fernandez

    Universidad de Cantabria

  • Jeffrey Bokor

    University of California, Berkeley

  • Jorge Iniguez

    Materials Research and Technology Department, Luxembourg Institute of Science and Technology (LIST), 5 avenue des Hauts-Fourneaux, L-4362 Esch/Alzette, Luxemburg, Luxembourg Inst of Science and Technology; University of Luxembourg

  • John William Freeland

    Advanced Photon Source, Argonne National Lab, Argonne National Lab, Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA, Argonne National Laboratory, Advanced Photon Source, Argonne National Laboratory

  • Javier Junquera

    Universidad de Cantabria

  • Long Q. Chen

    Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA, Pennsylvania State University, Department of Materials Science and Engineering, Pennsylvania State University

  • Sayeef Salauddin

    University of California, Berkeley

  • Lane Wyatt Martin

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

  • Ramamoorthy Ramesh

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