Tunnelling into the twisted Mott insulator Sr2IrO4 with atomic resolution

ORAL

Abstract

We studied the single-layered iridate Sr$_2$IrO$_4$ with a scanning tunneling microscope. The finite low temperature conductance enables the electronic structure of this antiferromagnetic Mott insulator to be measured by tunneling spectroscopy. We imaged the topography of freshly cleaved surfaces and measured differential tunneling conductance at cryogenic temperatures. We found the Mott gap in the tunneling density of states to be 2$\Delta$ = 615 meV. Within the Mott gap, additional shoulders are observed which are interpreted as inelastic loss features due to magnons.

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Authors

  • Armin Ansary

    Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506-0055

  • J. Nichols

    Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506-0055, University of Kentucky, Dept. of Physics and Astronomy, University of Kentucky

  • Noah Bray-Ali

    Joint Quantum Institute, University of Maryland, College Park, Maryland 20742-4111

  • Gang Cao

    Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506-0055, Center for Advanced Materials, Department of Physics and Astronomy, University of Kentucky, University of Kentucky

  • Kwok-Wai Ng

    Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506-0055