Tuning orbital-selective phase transitions in a two-dimensional Hund's correlated system

ORAL

Abstract

For describing the novel quantum phases in multi-orbital materials, Hund’s rule coupling (J) has attracted much attention. Various intriguing phases can occur by roles of J depending on the orbital occupancy. However, experimental confirmation of the orbital occupancy dependency has been challenging since controlling the orbital degrees of freedom normally accompanies chemical inhomogeneities. In this study, we demonstrate a method to investigate the role of orbital occupancy in J related phenomena without inducing inhomogeneities. By growing SrRuO3monolayers on various substrates with symmetry-preserving interlayers, we gradually tune the crystal field splitting and thus the orbital degeneracy of the Ru t2g orbitals. It effectively varies the orbital occupancies. Via in-situ angle-resolved photoemission spectroscopy, we observe a metal-insulator transition (MIT). The MIT occurs with orbital differentiation: concurrent opening of a band insulating gap in the dxy band and a Mott gap in the dxz/yz bands. Our study provides an effective experimental method for investigation of orbital-selective phenomena in multi-orbital materials.

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Publication: E. K. Ko et al., https://doi.org/10.48550/arXiv.2210.05621

Presenters

  • Tae Won Noh

    • Seoul National University
    • Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea

Authors

  • Eun Kyo Ko

    • Seoul Natl Univ
    • Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea

  • Sungsoo Hahn

    • Seoul Natl Univ
    • Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea

  • Changhee Sohn

    • UNIST Korea
    • Ulsan National Institute of Science and Technology, Republic of Korea
    • UNIST
    • Department of Physics, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea

  • Sangmin Lee

    • Department of Materials Science and Engineering and Research Institute of Advanced Materials, Seoul National University, Seoul 08826, Republic of Korea

  • Seung-Sup B. Lee

    • Seoul National University
    • Department of Physics and Astronomy, Seoul National University, Seoul 08826, Republic of Korea
    • Seoul Natl Univ

  • Byungmin Sohn

    • Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea

  • Jeong Rae Kim

    • Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea

  • Jaeseok Son

    • Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
    • Seoul Natl Univ

  • Jeongkeun Song

    • Seoul Natl Univ
    • Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea

  • Youngdo Kim

    • Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
    • Seoul national university

  • Donghan Kim

    • Seoul National University
    • Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
    • Seoul national university

  • Miyoung Kim

    • Department of Materials Science and Engineering and Research Institute of Advanced Materials, Seoul National University, Seoul 08826, Republic of Korea
    • Seoul National University

  • Choong Hyun Kim

    • Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea

  • Changyoung Kim

    • Seoul Natl Univ
    • Seoul National University
    • Department of Physics and Astronomy, Seoul National University
    • Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
    • Seoul national university

  • Tae Won Noh

    • Seoul National University
    • Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea