Interface induced polar metals by multi-mode coupling

ORAL

Abstract

Multi-mode coupling between various phonon modes in ABO3 perovskite oxides can be tuned by forming heterostructures, which can lead to precise control of their functionalities [1]. Considering the interest in ferroelectric properties in a metal i.e., in polar metals [2], an efficient way to induce ferroelectric-like (FEL) displacements in the centrosymmetric phase is by interface-induced coupling [3]. Here, using first-principles density functional theory (DFT) and DFT+U (static d-d Coulomb interaction) we have investigated (BaTiO3)m/(Metal)p/(BaTiO3)m' heterostructures [(m/p/m')= 6/3/7, 7/2/7, 7/1/8, m+p+m'= 16] to explore a new family of polar metals. We have chosen various metal blocks in a way that can represent a BTO/3dn/BTO system, where n= 1-6. We found that a FEL phase coupled with in-plane rotation of BO6 octahedra (a0a0c+) can be induced in the centrosymmetric 'metal' block when BaTiO3 is in the ferroelectric phase. The properties are found to depend strongly on the relative polarization direction of BTO units. [1]. S. Ghosh et. al. Phys. Rev. B. 92, 184112, (2015), [2] S. Ghosh et. al. Phys. Rev. Lett. 119, 177603 (2017), [3] H. Guo, PNAS, 114, E5062-E5069 (2017).

*DOE-DE-FG02-09ER46554 (S.G., S.T.P.), DOE-DE-SC0002136 (H.G , E. W. P)

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Presenters

  • Saurabh Ghosh

    • Department of Physics and Nanotechnology, SRM University
    • Dept. of Physics and Nanotechnology, SRM Institute of Science and Technology, India

Authors

  • Saurabh Ghosh

    • Department of Physics and Nanotechnology, SRM University
    • Dept. of Physics and Nanotechnology, SRM Institute of Science and Technology, India

  • Aafreen Fathima

    • Dept. of Physics and Nanotechnology, SRM Institute of Science and Technology, India

  • Hangwen Guo

    • Fudan University
    • Dept. of Physics and Astronomy, Louisiana State University, USA

  • E Ward Plummer

    • Louisiana State University
    • Department of Physics & Astronomy, Louisiana State University
    • Dept. of Physics and Astronomy, Louisiana State University, USA
    • Department of Physics and Astronomy, Louisiana State University, Baton Rouge
    • Physics and astronomy, Louisiana State University

  • Sokrates T Pantelides

    • Department of Physics and Astronomy, Vanderbilt University
    • Vanderbilt University
    • physics, Vanderbilt University
    • Physics, Vanderbilt University
    • Department of Physics and Astronomy and Department of Electrical Engineering and Computer Science, Vanderbilt University
    • Dept. of Physics and Astronomy, Vanderbilt University, USA