Electric field Controllable “Negative Capacitance” in Polar Skyrmions: Topological transition?

ORAL

Abstract

Complex topological configurations are a fertile arena to explore novel emergent phenomena and exotic phases in condensed-matter physics. For example, the recent discovery of polar skyrmions, vortices in superlattices of (PbTiO3)n/(SrTiO3)nsuggests the presence of a complex, multi-dimensional system capable of exotic physical responses. Here, we demonstrate electric field controlled room-temperature negative capacitance and topological phase transition in polar skyrmions. In epitaxially grown heterostructures of PbTiO3 and SrTiO3capacitance was found to be larger compared to its indivual constituent's capacitance SrTiO3, PbTiO3. This indicates the indicates the ferroelectric was stabilized in a state of negative capacitance at room temperature. This phenomenon could be controlled by electric field and temperature. The STEM measurement, Phase field and Second principle calculation confirms the stable negative capacitance is due to boundary of polar skyrmions.Such phenomena could advance ferroelectrics towards new levels of functionality.
Das, S, Tang, Y. L. et. al, Nature (under reviw);Yadav, A.K., Nelson, C.T. et al., Nature 530, 198-201 (2016);Shafer, P., García-Fernández. P. etal., Proc. Natl. Acad. Sci. USA115, 915 (2018).

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Presenters

  • 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

Authors

  • 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

  • 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

  • Pablo G. Fernandez

    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

  • 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.

  • Yun-Long Tang

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

  • 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.

  • Long Q. Chen

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

  • 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

  • Sayeef Salahuddin

    University of California, Berkeley, UC Berkeley, Department of Electrical Engineering and Computer Science, UC Berkeley

  • Ramamoorthy Ramesh

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