Effects of spin-orbit coupling on the metal-insulator transition in Sr2Ir(1-x)T(x)O4 (T = Rh,Ru)

ORAL

Abstract

We study the role of spin-orbit coupling (SOC) in the metal-insulator transition of Rh- and Ru-substituted Sr2IrO4. Although similar, Rh and Ru have significantly different effects in driving the insulator to metal transition. Whereas Rh substitution realizes a Fermi surface at concentrations of 0.16 and higher, Ru substituted samples are insulating for similar values. We study the progression of effective SOC in the Rh substituted samples through a method based on photoemission matrix elements. We find that Rh reduces the effective SOC. This interpretation is substantiated by cluster models which show that SOC mixes into an average of the two subspecies. This mixing however, is strongly dependent on orbitals having similar energies. We argue that this quantitatively explains the difference between Ru and Rh substitution: since Ru has one less electron, the orbital energies are different from Ir, hence SOC mixing is ineffective. The model thus does not only explain the observed reduction of SOC in the Rh doped samples, it also shows why this reduction does not occur in Ru doped samples, thereby demonstrating that SOC is a key parameter in describing the MIT in Rh substituted Sr2IrO4.

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Presenters

  • Berend Zwartsenberg

    Quantum Matter Institute, University of British Columbia, Department of Physics & Astronomy, University of British Columbia

Authors

  • Berend Zwartsenberg

    Quantum Matter Institute, University of British Columbia, Department of Physics & Astronomy, University of British Columbia

  • Ryan P Day

    University of British Colombia, QMI, University of British Columbia, Physics and Astronomy, University of British Columbia, Quantum Matter Institute, University of British Columbia, University of British Columbia, Department of Physics & Astronomy, University of British Columbia

  • Elia Razzoli

    University of British Colombia, QMI, University of British Columbia, Physics and Astronomy, University of British Columbia, Quantum Matter Institute, University of British Columbia, Department of Physics & Astronomy, University of British Columbia

  • Matteo Michiardi

    University of British Colombia, QMI, University of British Columbia, Physics and Astronomy, University of British Columbia, Quantum Matter Institute, University of British Columbia, Department of Physics & Astronomy, University of British Columbia

  • Nan Xu

    Swiss Light Source, Paul Scherrer Institute

  • Ming Shi

    Swiss Light Source, Paul Scherrer Institute

  • Jonathan Denlinger

    ALS, Lawrence Berkeley National Laboratory, Lawrence Berkeley National Laboratory, Lawrence Berkeley National Labotatory, Advanced Light Source, Lawrence Berkeley National Laboratory, Lawrence Berkeley Natl Lab

  • Stuart Calder

    Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge National Laboratory, Neutron Scattering Division, Oak-Ridge National Laboratory

  • Bumjoon Kim

    Pohang University, Pohang University of Science and Technology, Physics, Pohang University of Science and Technology, Department of Physics, POSTECH, Institute for Basic Science, Department of Physics, Pohang University of Science and Technology

  • Hidenori Takagi

    Department of Advanced Materials, University of Tokyo, Max Planck Institute for Solid State Research, Physics, University of Tokyo, University of Tokyo (Japan)

  • Ilya Elfimov

    Quantum Matter Institute, University of British Columbia, Stewart Blusson Quantum Matter Institute

  • Andrea Damascelli

    University of British Columbia, University of British Colombia, QMI, University of British Columbia, Physics and Astronomy, University of British Columbia, Stuart Blussom Quantum Matter Institute, University of British Columbia, Quantum Matter Institute, University of British Columbia, Department of Physics & Astronomy, University of British Columbia