Ferroelectric field and magnetic field effect on the spin-orbit coupled Mott insulator Sr2IrO4

ORAL

Abstract

The 4d and 5d transition metals are commonly characterized by a decreased Hubbard repulsion U which diminishes correlation effects, but simultaneously by an increased spin orbit coupling to create a new type of correlation effects which have been leading to such as spin-orbit coupled Mott insulators, Weyl semimetals, axion insulators and spin liquids. This rich physics allows small perturbations to create large effects in these strongly correlated materials. The Ruddlesden-Popper series of Srx+1IrxO3x+1 shows large differences in conductive behavior, where the n=∞ perovskite SrIrO3 is metallic while the n=1 Sr2IrO4 is an insulator due to a spin-orbit coupling band splitting to a Jeff=1/2 state. This state has many similarities to the high TC cuprate superconductors which show an S=1/2 state, which loses its antiferromagnetism and becomes superconducting upon hole doping. Likewise, theoretically it is argued that under electron doping it is possible to drive Sr2IrO4 superconducting. Here a ferroelectric field effect is used on ultrathin Sr2IrO4 films to drive it to a more metallic state, by playing on the competition between electron doping and the canted antiferromagnetic transition at ~200K.

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Presenters

  • Arnoud Everhardt

    Materials Science and Engineering, University of California, Berkeley, Materials Sciences Division, Lawrence Berkeley National Laboratory, Materials Science Division, Lawrence Berkeley National Laboratory, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands

Authors

  • Arnoud Everhardt

    Materials Science and Engineering, University of California, Berkeley, Materials Sciences Division, Lawrence Berkeley National Laboratory, Materials Science Division, Lawrence Berkeley National Laboratory, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands

  • Yun-Long Tang

    Materials Sciences Division, Lawrence Berkeley National Laboratory, Department of Materials Science and Engineering, University of California, Berkeley

  • Xiaoxi Huang

    Department of Materials Science and Engineering, University of California, Berkeley

  • Jay LeFebvre

    University of California, Riverside

  • Shane Cybart

    University of California, Riverside

  • R Ramesh

    Department of Physics, University of California Berkeley, California, USA, Department of Materials Science and Engineering, University of California at Berkeley, Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA., Department of Materials Science and Engineering, University of California, Berkeley, Department of Physics, University of California, Berkeley