Low-lying electronic structure and possible intrinsic gap control in J $=$ 1/2 Mott insulating perovskite iridate Sr$_3$Ir$_2$O$_7$

ORAL

Abstract

Using angle resolved photoemission spectroscopy, the ground state of perovskite iridate Sr$_{3}$Ir$_{2}$O$_{7}$ is found to be in close vicinity to a metal-to-insulator transition. Photoemission data reveal two bands extending up to surprisingly small binding energies around the Brillouin zone corner X, followed by a van Hove-like flat portion at the top of the valence bands. One of these bands form a saddle point while the other shows apparent spectral weight suppression along the the in-plane antiferromagnetic vector direction ($\Gamma $-$\Sigma )$, signaling a possible electronic response to the additional long range order. The energy scale of the Mott insulating gap shows considerable sample-to-sample variation, which points to possible intrinsic control of low temperature resistivity by apical oxygen deficiency - a process suggested by transport experiments and, importantly, similar to the doping process of the cuprates that gives rise to high temperature superconductivity.

*DOE Grant No. DE-FG02-05ER46200

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Authors

  • Chang Liu

    • Joseph Henry Laboratory and Department of Physics, Princeton University, Princeton, New Jersey 08544, USA

  • Su-Yang Xu

    • Joseph Henry Laboratory and Department of Physics, Princeton University, Princeton, New Jersey 08544, USA

  • Nasser Alidoust

    • Joseph Henry Laboratory and Department of Physics, Princeton University, Princeton, New Jersey 08544, USA

  • Madhab Neupane

    • Joseph Henry Laboratory and Department of Physics, Princeton University, Princeton, New Jersey 08544, USA

  • M. Zahid Hasan

    • Joseph Henry Laboratory and Department of Physics, Princeton University, Princeton, New Jersey 08544, USA

  • Tay-Rong Chang

    • Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan

  • Horng-Tay Jeng

    • Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan

  • Hsin Lin

    • Department of Physics, Northeastern University, Boston, Massachusetts 02115, USA

  • Robert Markiewicz

    • Department of Physics, Northeastern University, Boston, Massachusetts 02115, USA

  • Arun Bansil

    • Department of Physics, Northeastern University, Boston, Massachusetts 02115, USA

  • Chetan Dhital

    • Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA

  • Sovit Khadka

    • Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA

  • Yoshinori Okada

    • Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA

  • Vidya Madhavan

    • Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA

  • Stephen Wilson

    • Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA