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).

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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