Dimerization-Induced Cross-Layer Quasi-Two-Dimensionality in Metallic Iridate IrTe$_{2}$

ORAL

Abstract

IrTe$_{2}$ a layered chalcogenide metal composed of stacked layers of IrTe$_{6}$ octahedra, has recently received a lot of interest due to: (1) the structural phase transition ($T_{S}=$280 K) to a modulated structure characterized by the wave vector \textbf{\textit{q}}$_{\mathbf{0}}=$(1/5, 0, 1/5) and (2) the superconducting properties of the Pd/Pt-doped/intercalated samples. Using the crystal structure obtained from single crystal X-ray diffraction and first principle calculations we show that the mechanism for the structural phase transition is driven by the Ir dimerization and bonding, contrary to mechanisms proposed before based on: orbital-driven Peierls instability, crystal field splitting the Te $p$ orbitals and depolymerization of the inter-layer Te bonds. In this talk I will describe the Ir/Te dimers and the electronic structure calculations which reveal an intriguing quasi-two-dimensional electronic state, with planes of reduced density of states cutting diagonally through the Ir and Te layers. These planes are formed by the dimers exhibiting a signature of covalent bonding character development. The role of the electronic correlations and spin orbit coupling will be also discussed.

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Authors

  • Gheorghe-Lucian Pascut

    Rutgers University, NJ, USA

  • Kristjan Haule

    Rutgers The State University of New Jersey, Rutgers University, Department of Physics, Rutgers University, Piscataway, New Jersey 08854, USA, Rutgers Univ, Rutgers University, NJ, USA, Department of Physics and Astronomy, Rutgers University

  • Matthias J. Gutmann

    ISIS, UK

  • Sarah A. Barnett

    Diamond, UK

  • A. Bombardi

    Diamond, UK, Diamond Light Source,Didcot OX11 0DE, UK

  • Sergey Artyukhin

    Rutgers University, NJ, USA

  • Turan Birol

    Rutgers University, NJ, USA

  • David Vanderbilt

    Rutgers University, Rutgers Univ, Rutgers University, NJ, USA, Chinese Academy of Sciences, Rutgers University - New Brunswick

  • J.J. Yang

    Pohang University of Science and Technology, Korea, Pohang University of Science and Technology, Laboratory for Pohang Emergent Materials and Department of Physics, Pohang University

  • S.-W. Cheong

    Rutgers University, Department of Physics, Rutgers University, Rutgers University, NJ, USA, Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA, Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers U., NJ, USA, Rutgers, The State University of New Jersey, Department of Physics and Astronomy, Rutgers University, Rutgers Center for Emergent Materials and Department of Physics and Astronomy, 136 Frelinghuysen Road, Piscataway 08854, NJ, USA

  • Valery Kiryukhin

    Rutgers University, NJ, USA